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[ D A N P L O T A N D D A N C A M ]
DOCUMENTATION FILE
CAMPLOT.DOC
FOR
DANPLOT.COM v2.5 AND DANCAM.COM v2.5
THE TWO COMPANION
COMPUTER AIDED MANUFACTURING PROGRAMS
FOR USE WITH DANCAD3D v2.5
Copyright (c) 1989-1991 by Daniel H. Hudgins, All rights reserved.
Daniel H. Hudgins, 466 Diamond Street, San Francisco, CA 94114, USA
SEE ALSO THE FILE DANCAD3D.DOC ON THE DANCAD3D SHAREWARE DISKS.
USE THE PROGRAM PRINTDOC.EXE ON THE DANCAD3D SHAREWARE DISKS TO PRINT
OUT THIS FILE IN ORDER TO HAVE THE PRINT CENTERED PROPERLY.
You may not copy this DANCAM/DANPLOT disk, this documentation file
or printed copies of this documentation file (other that to make a
working copy for your own personal use) without obtaining express
written permission form the author of this disk, i.e. Daniel H.
Hudgins. Under no conditions is this DANCAM/DANPLOT disk to be sold
for more than $10. None of the files of the DANCAM & DANPLOT disk may
be altered, modified, deleted, or translated on copies of the DANCAM &
DANPLOT disk that are to be sold, shared, or loaned without express
written permission from Daniel Hudgins.
The latest version of DANCAM and DANPLOT come with the disk set
and manuals that are included with the DANCAD3D v2.5 user outfit. The
DANCAD3D user order form is accessed from the opening menu that comes
up when DANCAD3D v2.5 is run from DOS. Additional documentation and
schematics for use with DANCAM and DANPLOT are supplied with the
DANCAD3D user outfit.
Please read all disclaimers and all warnings, notices, and danger
statements before You use DANCAM or DANPLOT. Since DANCAM and DANPLOT
control motors, and other electro-mechanical hardware, the use of
DANCAM or DANPLOT can cause serious or fatal personal injury. It is
assumed that the user of DANCAM and DANPLOT understands the dangers
involved with working with power driven machinery, and high voltage
circuitry, and will take any and all safety precautions necessary to
protect himself and others from injury. Although DANCAM and DANPLOT
are being used successfully, DANCAM and DANPLOT may not function
properly at all times and are provided AS IS for you to USE ONLY AT
YOUR OWN RISK.
[1]
[ D I S C L A I M E R A N D W A R N I N G ]
DISCLAIMER
Please remember that DANCAM can DANPLOT are sold AS IS, please use
them ONLY AT YOUR OWN RISK. Daniel H. Hudgins will not be responsible
or liable for any loss, damage, or injury of any kind. Please read
the disclaimer that is in the DANCAD3D manual since it covers DANPLOT
and DANCAM as well. Also read the disclaimer in the file DANCAD3D.DOC
on the DANCAD3D shareware disks, as well as this disclaimer and the
warning below.
This documentation for DANCAM and DANPLOT may contain errors and
or omissions. Under no circumstances or conditions will Daniel
Hudgins be held accountable for any errors or omissions.
This documentation includes suggested connections for hooking up
devices to your computer's parallel port. Daniel Hudgins will not and
shall not be held accountable or liable for any loss or damage that
might occur to your computer to other devices. It is your
responsibility to check and verify all the appropriateness of
connections to your computer before turning on the power. Verifying
the appropriateness of connections may require you to read and
understand more information than this DANCAM and DANPLOT documentation
contains.
Under no circumstances are DANCAM or DANPLOT to be used in
equipment that is used for medical purposes. DANCAM and DANPLOT
should not be used in equipment that could cause injury to persons or
loss of property if the equipment or software failed to operate
properly.
The use of DANCAM or DANPLOT is disallowed if any laws might
require Daniel Hudgins to be in any way responsible or liable for any
loss or injury. DANCAM and DANPLOT may not satisfy occupational
safety laws in your state or country.
No license to third parties is expressed or implied. No violation
of copyrights or patents held by third parties is implied by the
suggested use and connection of DANCAM and DANPLOT. The user should
confirm that no copyrights or patents will be violated by his use of
DANCAM or DANPLOT.
The use of DANCAM or DANPLOT indicates full acceptance of all
disclaimers and an understanding that DANCAM and DANPLOT are only to
be used at the users OWN RISK.
In this documentation the what is said about using stepper motors
will also generally apply to servo motors and any other type of motors
that might be used. It is a fact that any component can and should be
expected to fail, therefore your safety depends on your not relaying
of any particular component to protect you from harm. To improve your
safety from harm use several stages of protection, so that if any
single safety measure fails you have several others to back the failed
[2]
[ D I S C L A I M E R A N D W A R N I N G ]
one up. Always be more careful than you think you need to be!
WARNING
Power driven and or automated equipment can cause serious injury
or even death. You must take serious efforts to protect yourself and
anyone else near such equipment. Do not place your hands or other
body parts near power driven equipment without first disconnecting the
power to the stepper motors (or other type of motors) in such a way
that the motors and tool cannot harm you or others. DANPLOT and
DANCAM are only to be used by people that understand the dangers
involved and have been trained in the necessary safety precautions.
Be aware that failure of electrical connections or computer
hardware/software related faults can cause motors to start
unexpectedly. To help avoid injury caused by unexpected motor starts
you should disconnect the motor power at both the AC input of the
motor power supply and the DC output of the motor power supply before
you expose yourself or others to the equipment. Evaluation of the
completeness of any safety measures is the users (your)
responsibility.
DO NOT USE any TSR program that puts a clock on the screen while
the DANCAM or DANPLOT programs are in use! Do not use any
multitasking, or print spooling programs while DANCAM or DANPLOT are
in use! Such programs interfere with the computers CPU timing and
therefore make the motors not run smoothly. Do not use the DOS screen
dump command, e.g. [Shift] and [PrtSc], while running DANCAM or
DANPLOT since the parallel port is not connected to a printer and the
motors or auxiliary relays may be accidentally turned on (the computer
may also lock up since the screen print command will not be getting
the correct printer messages!)
If the computer re-boots because of a power failure, your turning
the computer off, your pressing [Ctrl] & [Alt] & [Del], or any other
reason the voltage on the output pins of the parallel port may change
and activate the auxiliary relays and other equipment in an
inappropriate and possible harmful manner. You should investigate the
default state of the parallel port pins after a computer reboot to
determine if you have the high/low state for the output optimized to
minimize any hazard.
[3]
[ A B S T R A C T ]
ABSTRACT
DANCAM and DANPLOT are two utility programs that you can use to
automatically manufacture parts. DANCAM and DANPLOT run on your IBM
(tm) compatible personal computer and use your personal computers
parallel port to send motion control signals to almost any TTL signal
compatible steeper motor translator/driver module, as well as using
the parallel port to drive all the necessary control relays and to
read all of the necessary home, limit and pause switches. If you have
a desire to use servo motors in preference to stepper motors, a set of
plans for a special closed loop servo motor driver compatible with
DANCAM v2.52 and DANPLOT v2.52 is included in the DANCAD3D v2.5H user
outfit, write to Daniel Hudgins for full information and pricing.
Specifically DANCAM and DANPLOT are designed to read drawing files
made with DANCAD3D.COM v2.5 and control stepper motors movement in
such a way as to follow the lines drawn with DANCAD3D. You can attach
stepper motors to almost any 2 or 3 axis machine tool or plotting type
device's hand wheel (crank, knob) shafts to automate it. Additionally
DANPLOT can be used to drive 4 axis devices where the forth axis (the
"C" axis) keeps the cutting edge of a saber saw or knife blade pointed
into the direction of the tool motion.
DANCAM and DANPLOT offer very high possitional accuracy (when
properly installed) and can be used for applications requiring fine
accuracy to points spaced large distances (the actual accuracy of the
cutting tool location depends on the quality of the device you are
automating, e.g. flexing in the tool post and play in the ways will
cause the tool to be slightly misplaced, if the error is repeatable
you can adjust the tool path file with DANCAD3D to compensate for the
errors.)
Because DANCAM and DANPLOT are general purpose Computer Aided
Manufacturing programs you can use them to automate most if not all of
the types of machine tools you use. Additionally because of the
extreme low cost and high repeatable accuracy of DANCAM and DANPLOT
you may become interested in automating tasks that are currently done
with manual hand labor.
[4]
[ O V E R V I E W O F D A N C A M A N D D A N P L O T ]
ABOUT THE DANCAM AND DANPLOT DISK
The DANCAM and DANPLOT disk has several example files on it in
addition to the program files. Please read the file FILES.DOC for a
description of the files on this disk. Before you can use the
programs DANCAM or DANPLOT you will need to make a copy of this floppy
disk and then delete the *.DOC files on your disk working copy.
EXAMPLE: C>COPY A:*.* B:
C>DELETE B:*.DOC
The need to delete the *.DOC files is to make room for DANCAM and
DANPLOT to save their configuration files i.e. DANCAM.CFG and
DANPLOT.CFG. When you copy the configured versions of the programs
remember to copy the *.CFG file along with the *.COM files.
If you want to use DANCAM and DANPLOT from a harddisk just copy
them into an appropriate subdirectory, i.e. if DANCAD3D v2.5 is on the
harddisk just copy all the files into DANCAD3D subdirectory DC25.
EXAMPLE: C>COPY A:*.* C:\DC25\*.*
To print out this documentation file use the program PRINTDOC.EXE
on the DANCAD3D shareware disks. If your printer is on the serial
port use the DOS mode command to configure your serial port before
trying to print the file. PRINTDOC.EXE will print the file centered
on the page (the leading spaces have been omitted from this file to
save disk space.)
EXAMPLE: C>C:\DC25\PRINTDOC A:CAMPLOT.DOC PRN
C>C:\DC25\PRINTDOC A:CAMPLOT.DOC LPT2
C>C:\DC25\PRINTDOC A:CAMPLOT.DOC COM1
OVERVIEW OF HOW DANCAM AND DANPLOT WORK
DANPLOT and DANCAM are two programs that you can run on your
computer to manufacture parts. YOU DO NOT NEED to understand or have
any background in CNC or "G" codes to use DANCAM and DANPLOT. DANCAM
and DANPLOT work in a SIMPLE AND DIRECT MANNER, they simply move the
tool along lines and curves THAT YOU DRAW with DANCAD3D. All you have
to do is draw on DANCAD3D's drawing screen a series of lines and
curves in the order you want the tool to trace out those motions and
DANCAM or DANPLOT will FOLLOW THE MOTIONS YOU HAVE DRAWN OUT.
To use DANCAM and DANPLOT you simply go to a motor supply house
and purchase some stepper motors and driver modules (instructions and
schmatics for low cost stepper and servo motor driver modules and
power supplies you can build are included in the DANCAD3D v2.5 user
outfit.) You will also need a power supply (some driver modules are
powered from the AC line and do not require a power supply) and a 36
pin mating connector for your parallel port cable. Connect the motors
[5]
[ O V E R V I E W O F D A N C A M A N D D A N P L O T ]
to drive your machine's lead screws with timing belts and pulleys.
Follow the connections shown in the drawing HOOKUP1.2D that comes on
the DANCAD3D v2.5 shareware disks and connect up the motors, modules,
and relays to the mating 36 pin connector (note that use of the
information in this file and the HOOKUP drawings is at your own risk,
Daniel Hudgins is not responsible for any damage or loss that might
occur.) Connect the mating 36 pin connector to the printer end of your
parallel port printer cable. Run DANCAM and/or DANPLOT and select
menu option 4. from the DANCAM or DANPLOT main menu. Answer the
questions in the configuration menu so that the motors will move the
proper amount when the program is used. Press [E]scape to exit the
configuration section. Try using main menu option 3. to manually move
the motors. Use a dial gage if you have one to confirm that the tool
is moving the proper amount (when you test the movement make the tool
or work-piece move 0.25 inch two or three times in order to take up
the backlash in your machine, and ignore the first reading.) Quit
DANCAM or DANPLOT.
Now that you have an automated machine tool or plotter hooked up
to your computer you can use DANCAD3D v2.5 to make some ASCII type
data files for tool paths. Run DANCAD3D and select DRAW from
DANCAD3D's main menu. Draw the tool path. Save the tool path element
as an ASCII type file (if you save the ASCII tool path to a floppy
drive you can take the drawing from your home or office computer to
the computer in the shop and read the drawing from the shop computer's
floppy drive or copy the file to the shop computer's harddisk and read
(execute) the drawing from the shop computer's harddisk (a single
computer can be hooked up to many machine tools to have many parts
made simultaneously, or each machine can have its own computer and the
tool path file can be run separately and or concurrently on each
machine tool.)) Quit DANCAD3D.
Turn the power supply for the automation motors (DANCAM and
DANPLOT can control relays to turn things on, but for safety reasons
you should have a manual switch to control the master power supply.)
Run DANCAM or DANPLOT, select menu option 1., and enter the name of
the tool path, e.g. SOMEFILE.ASC or A:\SOMEFILE.ASC, to execute
(execute means trace out the path drawn by moving the tool or work-
piece relative to each other.) DANCAM or DANPLOT should then make your
part for you. When the tool path is finished DANCAM or DANPLOT will
return the tool to home position and be ready to make another part
from the same tool path or another tool path file. You can file the
floppy disk copy of the tool path so that if you ever need more parts,
or replacement parts, all you have to do is shove the floppy disk in
the computer and enter the tool path name to make another identical
part. If you have manufacturing stations around the world you can
send tool paths on floppy disks so that the remote stations can make
up parts on demand locally and reduce your shipping and inventory
costs.
DOS batch files can be used to operate DANCAM and DANPLOT
automatically to make several parts. The machine operator DOES NOT
NEED TO USE ANY OF THE MENUS in DANCAD3D, DANCAM, and DANPLOT to
[6]
[ O V E R V I E W O F D A N C A M A N D D A N P L O T ]
manufacture parts. The machine operator does need to understand the
meaning of some of the messages that come on the screen (such as the
DOS PAUSE command telling him to press ANY-KEY when ready) or at least
know enough to alert a more knowledgeable operator when something goes
wrong. The machine operator should also be told that the power driven
tool can move unexpectedly and hurt him, therefore THE POWER TO THE
MOTORS COILS SHOULD ALWAYS BE SWITCHED OFF BEFORE EXPOSING HIMSELF TO
THE EQUIPMENT. Safety switches on the equipment access covers to turn
off the motor coil power are advisable to help reduce injuries (to
maintain possitional accuracy the logic power to the motor driver
modules should not normally be switched off in the middle of a tool
path execution, so when hooking up DANCAM and DANPLOT you should try
to wire up two separate power switches: one for the motor coil power,
and the other for the motor driver module logic power.)
To summarize, using DANCAM and DANPLOT takes these steps:
PHASE ONE: HOOKING IT UP
1. Hook up automation motors and switches mechanically to machine.
2. Hoop up electrical connections to modules and switches.
3. Configure DANCAM and DANPLOT to fit your mechanical hook up.
4. Test the installation to make sure the motors are working.
PHASE TWO: COMPUTER AIDED DESIGN
1. Use DANCAD3D to draw tool paths for the tool paths needed.
2. Save the tool paths to floppy disks.
3. Write a DOS batch file to control the manufacture of the parts
needed, and save the batch file to the floppy disk with the
corresponding tool path files. Set up the AUTOEXEC.BAT on the shop
computer so that the user will be prompted to insert the floppy
disk with the tool path and batch file to control the number of
parts to make. For safety, the batch file should prompt the
operator to turn the motor power on and off at the appropriate
points in the manufacturing cycle.
PHASE THREE: MACHINE OPERATION
1. Turn power on to the shop computer. The AUTOEXEC.BAT file will
automatically prompt the operator to insert the tool path disk.
The AUTOEXEC.BAT file then runs the batch file on the tool path
floppy disk (in order to have the AUTOEXEC.BAT file run the batch
file of the floppy disk you would always use the same filename for
the batch file on the floppy disk, e.g. GO.BAT.)
2. Operator inserts the stock and turns the motor power on.
3. Operators presses [Any-Key] to start making a part.
4. Operator is prompted to turn the power off, insert stock, and turn
the power back on (it is important that a manual safety power
switch be used since automatic control of power may not be reliable
[7]
[ O V E R V I E W O F D A N C A M A N D D A N P L O T ]
(the manual control may not be reliable either, but the manual
control of the power puts the responsibility for motor power on the
user/operator).)
5. The manufacturing cycle continues under the direction of the batch
files on the tool path floppy disks (i.e. GO.BAT can prompt the
user to insert further floppy disks and run sub-batch files.)
Phase three is of course not necessary if you are going to be the
operator of the machine. In the case that you are doing all the work
yourself you would save the data file on your harddisk from DANCAD3D
and then run DANCAM or DANPLOT, turn on the power for the machine, and
enter the filename of the tool path you saved to your harddisk.
[8]
[ P R O G R A M F E A T U R E S ]
PROGRAM FEATURES
DANCAM and DANPLOT both have several features that make setup and
operation simple and relatively easy to accomplish:
* All commands displayed on screen.
* Menu driven configuration is adjustable to any units.
* Works with tool paths drawn in metric, inch, or other units.
* Motor testing utilities to check maximum motor speed under load.
* Jog menu lets you position tool manually and has position read out.
* Can be paused while making parts from keyboard or switch on port.
* Supports up to four auxiliary relays to control anything.
* Has automatic or manual home up to home switches.
* Limit switches can be used to protect against out of range movement.
* Can be operated from dos command line automatically.
* Can be automatically operated from DOS batch files.
* Uses user accessible DANCAD3D ASCII data file type.
* Overall scaling factor to adjust part size.
* Adjusts to any pitch lead screws or drive chain.
* High accuracy over large distances of tool travel.
* Works with any motor driver using step pulse and direction signals.
* Feed rates can be installed from rapid movement to very slow.
* Feed rate change, auxiliary relay toggle, and pause can be
controlled automatically from line colors in the tool path file.
* Installable delay after relay toggle lets equipment settle down.
* Automatic backlash compensation when needed.
* DANCAM is fully three dimensional and can make any three axis shape.
* DANCAM and DANPLOT will run on almost any low cost PC compatible.
* Low cost simple connection to parallel port, LPT1, LPT2, OR LPT3.
When run on a 10 MHz 80286 computer DANCAM and DANPLOT can produce
about 3420 step pulses per second which would run servo motors with
200 steps per revolution at a speed of about 1026 RPM. Most stepper
motors have a reliable top speed less than 200 RPM so when stepper
motors are used the reliable operation of the motors limits the top
speed obtainable and not DANCAM or DANPLOT. The built in rate
multiplier can be used to increase the step angle for servo drives
(i.e. to 3.6 degrees) to get speeds of 2000 rpm or more since servo
motors are normally feed through a 6:1 or 8:1 reduction before driving
a 5 tpi lead screw, giving about 300 RPM at the lead screw or a feed
of 60 inches per minute.
[9]
[ A P P L I C A T I O N S ]
APPLICATIONS FOR DANCAM AND DANPLOT
DANCAM and DANPLOT are similar programs, but each one has been
optimized for different applications. DANCAM is designed for
applications that require the tool or actuator to move between points
at any location in three dimensions. DANPLOT is optimized for working
on flat material, e.g. sheet or plate, and will automatically lift the
tool or turn off the cutting flame or laser beam before moving to the
next point in the drawing file. In other words DANCAM is used used
for applications like 3D milling, and DANPLOT is used for plotter like
work such as engraving and torch cutting.
Both DANPLOT and DANCAM can draw circles and curves of any type.
DANCAM can manufacture any part that can be produced on a three axis
machine tool. The production of circles and curves takes place in
DANCAD3D as part of the preparation of the drawing of the tool path.
For complex contoured surfaces the tool path must define points that
are more closely spaced than for the tool paths of parts than have
flat surfaces. In the event that the tool path is to complex to fit
entirely in DANCAD3D's workspace at once, the required tool path can
be drawn in sections, and chained together for use with DANCAM or
DANPLOT. DANCAM and DANPLOT can read tool path files of any length.
DANCAD3D has special macro commands that can produce swept or
contoured surfaces. The macro commands for DANCAD3D are explained in
detail in the DANCAD3D manuals and example disks that come with the
registered user outfit.
APPLICATIONS DANCAM CAN BE USED FOR
MAIN USES OF DANCAM
* Three axis fully Three-Dimensional vertical milling.
* Operation of lathes.
* Cutting foam and other materials with hot wires.
* Flame cutting where the torch height needs to be adjusted.
* Laser cutting where the laser height needs to be adjusted.
* Drilling holes to varying depths.
ADDITIONAL POSSIBLE USES FOR DANCAM
* Spray application where sprayer moves in three dimensions.
* Glue application where applicator moves in three dimensions.
* Welding, spot or arc.
* Parts insertion, screw insertion, or nailing.
* Automated warehouse loading and unloading.
* Three axis motion control photography.
* Automation of a motion picture animation stand.
* Dipping of parts for coating by use of a gripper.
* Processing film, PC boards, or micro chip wafers.
[10]
[ A P P L I C A T I O N S ]
In addition to the linear three axis applications noted above
DANCAM can be used to have one axis or more move in a non-linear
manner. For instance the X axis could control a rotating table, so
when the drawing for the motion of the X axis is drawn with DANCAD3D
the person drawing the tool path would use units of arc (i.e. 0 to 360
degrees) rather than units of distance (e.g. 0.001 inch as +/- 10
inches.)
For lathes the third axis in DANCAM can be used to control the
spindle speed by connecting a small stepper motor to the shaft of an
SCR speed control for the spindle motor.
THREE AXIS APPLICATIONS WHERE DANPLOT CAN BE USED
* Building a large pen plotter to plot drawings full life size.
* Engraving scales and lettering.
* Cutting fabric or leather from a pattern.
* Drilling printed circuit boards.
* Drilling holes to constant depth, slow down & fast up motion option.
* Flame cutting with automatic flame control on the Z axis.
* Laser cutting automatic laser on and off control on the Z axis.
* Automated routing of wood for cabinets and stair runners.
* Stamping or punching of sheet metal or other material.
* Glue, Grease, Potting compound, OR Oil application.
With DANPLOT the third (Z) axis can be used in several ways: you
can control a stepper motor, you can control a relay, or you can
control a solenoid. The normal use of the stepper motor for the Z
axis would be to raise and lower the tool, such that the tool is not
in contact with the work-piece when the tool moves to the next
starting point if the line segments drawing in the file being executed
to not touch. Additionally the Z axis stepper motor can be used to
open or close a valve or rheostat. A relay on the Z axis direction
control line can be used to turn a laser or other electrical device on
or off. A solenoid triggered by the Z axis could be used to stamp or
punch the sheet material.
FOUR AXIS APPLICATIONS WHERE DANPLOT CAN BE USED
* Knife cutting of signs out of vinyl.
* Saw cutting of wood with a Saber, Band or Scroll saw.
* Cutting fabric or leather from a pattern.
* Broaching of key ways, groves, or gear teeth.
* Automating nibbling tools.
The forth or "C" axis (the c axis is rotation around the Z axis,
such that the cutting edge of the tool is parallel to the Z axis) in
DANPLOT will rotate the cutting edge of a knife or recriprecating saw
so the cutting edge always faces into the direction of the motion the
tool as the tool moves through the work-piece. A tolerance on how
[11]
[ A P P L I C A T I O N S ]
large a C axis angle change is required before the tool will lift is
available to speed the cutting of curves and circles (normally in
knife cutting no harm comes if the knife rotates in the work-piece as
circles are cut out, but you will want (and DANPLOT will perform) a
tool removal, tool rotation, and tool insertion when large angle
changes (such as at a 90 degree corner) need to be made.
[12]
[ G E N E R A L I N F O R M A T I O N ]
GENERAL INFORMATION
To use DANPLOT and DANCAM you will need to create a text file that
contains information on the end points of line segments, such that the
line segments define the path you want your tool (or work-piece as the
motion between the tool and work-piece is relative) to move through
space. The easiest way to create the necessary file of line segment
data is to use DANCAD3D v2.5 to draw the line segments in the order
you want them and in the direction you want the motion to proceed.
The necessary line segment data file can also be made with a text
editor or by a data file conversion program (to convert some other
data filetype such as DXF, HPGL, or "G" code, into DANCAD3D v2.5 *.ASC
file format.) Information about the DANCAD3D ASCII data file format is
given in the DANCAD3D technical reference manual, but is not needed to
use DANCAM and DANPLOT since DANCAD3D will create the proper file
format for you automatically.
DANPLOT and DANCAM are very similar programs but have each have
special features to make them work better for their intended task.
When you install DANCAM and DANPLOT by using the configuration
utilities accessed from DANCAM's or DANPLOT's main menu you should
keep in mind the different applications that the programs are designed
for.
DANPLOT is designed for use for working on flat or sheet material.
The Z axis for DANPLOT has two states, up or on and down or off.
DANPLOT can be used to build large plotters for plotting large
drawings. A "C" axis motor can be used with its rotational axis
parallel to the the Z axis in order to point the cutting tool into the
direction of the motion of the cut (i.e. for use with knifes and saber
saws.) The Z (pen) axis motor can be replaced with a relay to control
(toggle) a laser or torch automatically (the Z axis direction pin on
the port connector indicates the state, on or off.) Only the line
segments that will appear on the work-piece need to be in the data
file since DANPLOT will automatically lift the tool clear (turns off)
of the work-piece when moving between the drawn line segments and when
the tool path is done. Tool paths for use with DANPLOT have all
points in the Z = 0 plane.
DANCAM is designed for use for working on 3D parts where the tool
moves in all three dimensions. The Z axis in DANCAM is equal to and
interchangeable with to the X axis and Y axis. DANCAM is also useful
for 2 axis work where the full motion of the tool will be drawn out.
With DANCAM it is best to draw all motions out fully, including a safe
path to the start of cutting, controlled feed rate for the cuts (the
change in feed rate is accomplished by changing the line color in the
tool path drawing), and a safe path from the final cut back to the
home position (you can draw every other line segment in the tool path
for DANCAM to reduce the total number of line segments in the data
file, if you keep in mind that DANCAM will always take the shortest
path through three dimensions to the next first point of the next line
segment.)
[13]
[ G E N E R A L I N F O R M A T I O N ]
When making a tool path files for use with DANCAM or DANPLOT keep
the differences between the way the programs carry out the execution
of line segments in the drawing file in mind.
DANPLOT will read two types of file (ASCII and Plotter driver
output) made with DANCAD3D. You can draw a tool path as a set of line
segments or as a set of dots (holes to be drilled can be indicated by
dots) with DANCAD3D without connecting the dots since DANPLOT will
automatically lift the tool before moving to the next point (i.e.
DANPLOT works like a pen plotter, such that the pen will automatically
lift and move to the next line segment without drawing unwanted
connecting line segments that were not in the DRAWING made with
DANCAD3D.) DANPLOT can also read special plotter driver output files
made in DANCAD3D with the DANPLOT.PLT plotter driver that accompanies
DANPLOT on this disk. The plotter driver DANPLOT.PLT would be used
for applications such as engraving that require DANCAD3D's line
thickness attribute to be carried accurately to the finished result.
For all applications other than engraving use DANCAD3D's ASCII
filetype for tool paths that will be used with DANPLOT.
DANCAM works like DANPLOT except the movement of the tool is fully
3D, with all 3 axis motors being simultaneously controlled by the
lines you draw with DANCAD3D. DANCAM only reads the DANCAD3D v2.5
ASCII file format.
DANCAM is useful for most 3 axis tasks such as vertical milling.
You do however need to draw the tool path fully as a continuous series
of line segments. If you skip a line segment DANCAM will take the
shortest path to the next given point or to the home position
currently installed in DANCAM's configuration menu if there is no next
point to go to. So when you use DANCAM you should always draw all the
movements you want the tool to make, including the safe path clear of
the work-piece when done (in DANPLOT to tool automatically lifts to
clear the work-piece when done and goes home, DANCAM can not
automatically know what a safe return path is since dovetail mills or
other odd shape cutters may be in use (DANCAM will take the shortest
path from the last point drawn to home when done, so make sure the
last point in the tool path is clear of the work-piece!).)
HOW TO USE DANCAM AND DANPLOT
In general the use of DANCAM and DANPLOT follows these steps:
1. Build or buy a machine to automate. Generally you will want the
lead screws that have about 5 threads per inch so that the stepper
motors 200 or 400 steps per shaft rotation will give a resolution
of 0.001 or 0.0005 of an inch. Chain or timing cable drive in
place of a lead screw is an excellent choice for drives that
require less resolution and faster feed rates. Always try to
minimize inertia in components that must be driven, i.e. use small
[14]
[ G E N E R A L I N F O R M A T I O N ]
radius aluminum pulleys.
2. Install stepper motors on your machine. Use timing belts or
flexible shaft (bellows) couplings between the motor shafts and
lead screws to reduce noise and lost steps caused by vibration in
the motor coupling. Stepper motors get hot (80C to 85C) in
operation so proper mounting would allow the conduction of heat
from the motor and circulation of cooling air. Used or surplus
stepper motors can be purchased for a fraction of what new motors
cost. In general stepper motors should have a rated holding torque
that is at least FOUR TIMES THE TORQUE that will be required at the
operating RPM (the torque of stepper motors falls off as the motor
turns faster, so that a motor rated at 500 inch/ounce holding
torque might only have 200 inch/ounce at 60 RPM, and only 100
inch/ounce at 120 RPM, with the torque falling completely to zero
at 180 RPM.) Using stepper motors that are two small, and or
running the motors faster than they can reliable go is the major
cause of problems people have with stepper motors. Also stepper
motors need to be operated at 4 to 6 times their rated voltage to
give satisfactory results (a constant current stepper translator
module or resistors in series with the motor windings are required
to prevent the motor from overheating when operated at high
voltages, i.e. 48 to 96 volts.)
3. Buy or build the stepper motor translator modules and motor power
supplies (instructions for building the electronics required are
included in the DANCAD3D v2.5 outfit's manuals.) Stepper motors
generally operate with two coils (phases) on so the current draw is
double the rated current, e.g. three motors rated at 2 Amps will
require a power supply that can deliver at least 12 amps. The
stepper driver translator modules you will need are available form
your local motor distributor. Most stepper motor manufactures
supply driver modules optimized for their own brand of motors.
Surplus or used stepper motors can be purchased for a fraction of
what new motors cost, e.g. 500 inch ounce motors can be found for
less than $75. If you want to use solid state relays to control
the spindle of your machine or other auxiliary device buy solid
state relays that are rated for input of 3 volts DC or less since
the parallel port cannot supply more than 3 volts (if more power is
needed than the parallel port can supply a TTL buffer chip such as
the 74H07 and pull-up resistors (approximately 330 ohm) can be used
amplify the signal.) You can build your own stepper driver modules
to drive three five amp motors for about $100 or less depending on
how fancy you want to get. Ready made translator modules cost from
$50 to $600 per axis depending on the power and speed required.
4. Use the diagram HOOKUP1.2D on the DANCAD3D v2.5 shareware or
program disks to connect the stepper motor translator driver
modules to your computers parallel port. If four auxiliary relays
are to be used a 5 volt 500ma power supply (about a $10 item) will
be required for the pull-up bias, otherwise the auxiliary C and D
outputs can be used to pull-up the home and limit switch inputs (X,
Y, and Z home switch inputs being pulled up through 10K ohm
[15]
[ G E N E R A L I N F O R M A T I O N ]
resistors to auxiliary C output, and the pause/limit input being
pulled up through a 5K ohm resister to the auxiliary D output pin.)
5. Run DANCAM and DANPLOT and install the values for speed and
resolution that correspond to your machine. Test the motors under
load to make sure they can keep up with the movements they will
need to make. If the motors "louse steps" (that is slip and fail
to rotate to the proper position) under load use a larger Pulse
With Factor (p.w.f.) to give the motor time to complete one step
before another is requested (if a stepper motor louses steppes the
rotor will no longer have the proper rotational position (until the
motors are sent home again which is a good reason for installing
the home switches.)) Reducing the motor current to 80% of the rated
current can sometimes reduce lost steps caused by resonance in the
middle speed range.
6. Run DANCAD3D, draw a tool path, and save the tool path drawing as
an ASCII data file (or a plotter driver output file if you need the
line width feature for DANPLOT.)
7. Run DANCAM or DANPLOT, select menu option 1, and enter the file
name of the ASCII (*.ASC) tool path file you just saved from
DANCAD3D. If you did the installation properly your first part
should come out as designed. If the first part is not proper
adjust the installation and or the tool path drawing and try again.
Keep in mind that DANCAM and DANPLOT can run from the DOS command
line and therefore from DOS batch files. Operators of equipment do
not need to use any of DANCAM or DANPLOT's menus since you can
write a batch file to read the data file from a floppy disk
automatically.
[16]
[ D O S C O M M A N D L I N E A N D B A T C H F I L E S ]
EXAMPLE OF HOW TO RUN DANCAM OR DANPLOT FROM THE DOS COMMAND LINE
To operate DANCAM or DANPLOT from the DOS command line simply
enter DANCAM or DANPLOT followed by a space and then the name of the
data file to be plotted and then followed by another space and the
number 1 (or 1 or 2 for DANPLOT.) The number following the data
filename is equilevent to the menu option number from DANCAM's or
DANPLOT's main menu.
EXAMPLE: C>DANCAM A:DATAFILE.ASC 1
C>DANPLOT A:DATAFILE.ASC 1
If you want to have one of the other menu options come up from the
DOS command line you can use the dummy filename NUL.
EXAMPLE: C>DANCAM NUL 3
C>DANPLOT NUL 3
EXAMPLE OF BATCH FILES THAT AUTOMATICALLY RUN DANCAM OR DANPLOT
The following DOS batch file will make parts from data files saved
on floppy disks. Note that all the data files should have the same
name (when you save the DOS batch file you should always use the
filename extension *.BAT.)
EXAMPLE: :START
ECHO OFF
CLS
ECHO PUT TOOL PATH DISK IN DRIVE A:
PAUSE
DANCAM A:DATAFILE.ASC 1
GOTO :START
Since the floppy drives are somewhat slow you can get faster and
smoother plots by coping the data file to a harddisk or RAM disk (the
delay for the floppy drive to come up to speed when data is being read
will cause the cutter to idle for a moment periodically, a problem
that can be avoided by reading the data file from a harddisk or RAM
disk.)
EXAMPLE: :START
ECHO OFF
CLS
ECHO PUT TOOL PATH DISK IN DRIVE A:
PAUSE
COPY A:DATAFILE.ASC C:\DC25\*.*
DANCAM C:\DC25\DATAFILE.ASC 1
GOTO :START
You can have DANCAM automatically run after you quit DANCAD3D by
using a DOS batch file. To break a loop in a DOS batch file you need
[17]
[ D O S C O M M A N D L I N E A N D B A T C H F I L E S ]
to press [Control] & [C] while the batch file is operating.
EXAMPLE: :START
CLS
DANCAD3D
DANCAM
GOTO :START
[18]
[ H A R D W A R E R E Q U I R E M E N T S ]
HARDWARE REQUIREMENTS
Although DANCAD3D requires a fast computer and harddisk, DANPLOT
and DANCAM can be used with a less expensive system. One advantage of
using a less expensive computer in the shop with the automated
equipment is that if the shop computer is damaged you will not have to
spend much to repair it. In applications requiring higher motor shaft
speeds (i.e. Greater than about 100 RPM) a 80286 replacement mother
board can be put in an XT type case (replacement 80286 mother boards
only cost about $140 or less.) Since a 10MHz 80286 XT size AT mother
board can run as much as 8 times as fast as a 4.7MHz 8088 XT mother
board it is very much worth the slight added cost to use a 80286
mother board for DANCAM or DANPLOT.
DANCAM and DANPLOT will work on almost any IBM (tm) compatible PC
that has one floppy drive and a IBM (tm) PC standard parallel port.
No special hardware is required for the computer. Many standard
stepper motor driver modules and solid state relays can be connected
directly to the parallel port. The signals from the parallel port can
be boosted with inexpensive parts to drive almost any other stepper
driver module or relay that requires more power than the power the
parallel port can supply.
COMPUTER: 100% IBM PC-XT or AT compatible.
PORTS: One Parallel Port is required, i.e. LPT1, LPT2, or LPT3.
VIDEO: Any 80 column by 25 line video text display.
MEMORY: 192KB RAM DOS system memory, 128KB or more free.
DRIVES: 1 floppy disk drive. Reading the tool path data file from a
RAM disk can avoid periodic short interruptions due to
blocks of data being loaded from the data file. If you have
640KB on the computer you are using for DANCAM or DANPLOT a
RAM disk program to make a 448KB RAM disk from your DOS
system memory and have enough left over to run DANPLOT and
DANCAM (you would copy the ASCII tool path data file into
the RAM disk, and have DANPLOT of DANCAM read the tool path
from the RAM disk drive.) A RAM disk is created by running a
small utility program before you run DANCAM or DANPLOT. RAM
disk utility programs are available from ShareWare dealers.
CABLES: You will need a parallel port cable. If you have a printer
connected to your computer you can use that cable. To
connect the wires to the translator modules you will need a
Centronics 36 pin connector that will mate with your printer
cable. You can then solder wires onto the Centronics
connector rather than your printer cable and that will allow
you to disconnect the printer cable from the Centronics
connector at any time to use the printer cable on your
printer (reboot your computer after using DANCAM or DANPLOT
[19]
[ H A R D W A R E R E Q U I R E M E N T S ]
before you use your printer.) If you buy a printer switch
box make sure all of the needed pins are connected since
some cheaper switch boxes may not connect all of the pins.
The wire going between the parallel port pins and the input
pins of the translator modules should be shielded.
Microphone or video coaxial cable can be used with the
shields of the two cables being tied to common (one cable
for the step signal, and one cable for the direction
signal.) Electro-Magnetic noise can be a problem because of
a high current that flows through the wires that connect to
the motor power supply and to the motors themselves. Always
keep the step and direction cables as separated and far away
from the motor coil wires as you can. Putting a 2.2K ohm
pull up resistor from the step and direction inputs of the
translator module to a positive five volt regulated supply
can help reduce the input impedance of the translator module
and therefore the voltage of induced electro-magnetic noise.
Opto isolators, or LC or RC low pass filters on the inputs
of translator modules can also help reduce incorrect
triggering of the translator modules since opto isolators
and filters reduce the input impedance. To filter the step
and direction signals at the input of the translator module
connect a 1000 pf capacitor from the input to common,
connect a 2.2K ohm resistor from the input to +5 volts, and
connect a 100 ohm resister between the input of the
translator and the parallel port signal. If adequately
shielded and filtered the parallel port to translator cable
can be as long as 50 feet.
Wire for connecting the motors should be stranded and large
enough to handle the current required, i.e. 14 to 16 gage.
The wires for the limit and home switches can be rather thin
(22 gage) since very little current flows through the
switches.
MODULES: Stepper motor translator driver modules for stepper motors.
Hundreds of different driver modules are available to drive
different types of stepper motors. You will want TTL signal
compatible modules that have MOTOR STEP (pulse) and motor
DIRECTION (cw/ccw) inputs. Since steeper motors need to be
operated at voltages above what the motors are rated for the
stepper motor translator you purchase should offer some
constant current or current cutback feature to keep the
motors from burning up when they stop turning (stepper
motors get hottest when run slowly or are stopped.) Two
types of translator module that give good performance are
Bipolar chopper and Bilevel Bipolar. Bipolar drives give
more torque at medium speeds than Unipolar driver modules.
You should check that the stepper motors you are going to
use are compatible with the driver type you want to use.
Regardless of the type of module selected the top motor
speed will be less than the motor's best if the motor supply
[20]
[ H A R D W A R E R E Q U I R E M E N T S ]
voltage is less than five times the rated motor voltage,
e.g. a motor rated at 5 volts will run well with a 25 volt
supply, but a 25 volt motor will need a supply voltage of
125 volts to run well. The maximum rated voltage of the
motor driver module of course limits the supply voltage you
can use. Modules also have a rated range of motor coil
current they can handle (the coil current for the motors
should never exceed the rated current!)
RELAYS: Solid state relays such as the HAMLIN model 7521D or
equivalent can be used to control auxiliary devices directly
form the parallel port. The solid state relay should
operate from a 3 volt or smaller signal. Solenoid relays
can be controlled from the parallel port if you use a
transistor and DC power supply (instructions for circuit
details of such advanced wiring are in the DANCAD3D outfit's
technical information.)
POWER: External power supply. You will need a power supply
powerful enough to drive all the stepper motors you are
using. For medium duty tasks this would be 20 to 50 amps at
35 to 96 volts (stepper motors are run at voltages 4 to 6
times their rated voltage, so if you have motors rated at 10
volts you would want to have at least a 50 volt power supply
(how high the power supply voltage can be is of course
restricted by the maximum voltage of the translator modules
you will be using.)) To determine the total current required
figure that two coils will be drawing current in each
stepper motor so if your motors are rated at 1 amp per coil
and you have 3 motors you will need 6 amps plus another 4 to
6 amps for "headroom" due to the dynamic nature of the motor
load. To assure that the motors can get all the current
they need while stepping I recommend that you put a 20000 mf
capacitor across the power supply input of each of your
motor driver modules. A 5 volt 500 ma power supply may also
be required to bias any pull-up resistors required.
SWITCHES: Three Normally Open (N.O.) micro switches for home switches.
Six Normally Closed (N.C.) micro switches for limit
switches. One Normally Closed (N.C.) toggle switch for
pause switch. One Normally Open (N.O.) push button for
bypass button.
RESISTOR: Five 2.2K ohm 1/4 watt, for pull-up of the switch inputs
(pull-up resistors connect from TTL logic IC's inputs or
outputs to a plus five volt power supply (the common from
the five volt power supply would of course connect to the
logic common or ground.)) Since the switches connect between
the input pins of the parallel port and common the pull-up
resistors are needed to insure that the input pins are
always at logic high (logic high is 2.8 to 5.0 volts.) If
you do not want to use a special 5 volt supply for the limit
and home switch inputs you can use 10K ohm 1/4 watt
[21]
[ H A R D W A R E R E Q U I R E M E N T S ]
resistors from the input pins to auxiliary outputs C and D
(of course auxiliary C and D cannot then be used for relays
since they will need to be logic high all the time.)
HARDWARE: To mount the motors you will need flexible shaft couplings
(metal bellows type) or timing belts and pulleys. It is
important that the coupling used on the stepper motor have
about 0.5 degree of give (elasticity) so that the motor can
step easily and smoothly and without excessive vibration.
[22]
[ H O O K U P C O N E C T I O N S ]
HOOK UP CONNECTIONS TO THE PARALLEL PORT
The complete schmatic for the basic DANCAM and DANPLOT hook up is
provided in drawing file HOOKUP1.2D on the DANCAD3D v2.5 shareware
program disks. Printing out the HOOKUP1 drawing will make reading
this section much more understandable. Additional schmatic diagrams
are included in the DANCAD3D outfit. This following information gives
all the basic connections for using DANCAM and DANPLOT.
DANPLOT and DANCAM use the same basic connections to the pins of
the parallel port. The basic connections to the 36 pin printer end of
the Centronics parallel port cable are:
Pin No.
36 18
35 17
34 16
TIE TO COMMON - 33 15
AUXILIARY INPUT - 32 14
AUXILIARY RELAY "D" OUTPUT - 31 13 - Z AXIS HOME SWITCH INPUT
TIE TO COMMON - 30 12 - Y AXIS HOME SWITCH INPUT
TIE TO COMMON - 29 11 - X AXIS HOME SWITCH INPUT
TIE TO COMMON - 28 10 - LIMIT & PAUSE SWITCH INPUT
TIE TO COMMON - 27 09 - AUXILIARY RELAY "B" OUTPUT
TIE TO COMMON - 26 08 - Z AXIS DIRECTION OUTPUT
TIE TO COMMON - 25 07 - Y AXIS DIRECTION OUTPUT
TIE TO COMMON - 24 06 - X AXIS DIRECTION OUTPUT
TIE TO COMMON - 23 05 - AUXILIARY RELAY "A" OUTPUT
TIE TO COMMON - 22 04 - Z AXIS STEP PULSE OUTPUT
TIE TO COMMON - 21 03 - Y AXIS STEP PULSE OUTPUT
TIE TO COMMON - 20 02 - X AXIS STEP PULSE OUTPUT
TIE TO COMMON - 19 01 - AUXILIARY RELAY "C" OUTPUT
All of the input pins must be "pulled up" to logic high through
2.2K ohm 1/4 watt resistors to a +5 volt regulated power supply (you
should be able to find a +5 volt 500 milliampere power supply for less
than $10 (you can use three flashlight 1.5v dry cells in series to get
about 4.5 volts, but NEVER use more than 5 volts or less than 3
volts.)) ALWAYS check that the MINUS (-) end of the five volt supply
connects to the COMMON point, since reversed connections will damage
your parallel port and possibly other parts of your computer. If you
do not want to bother with a +5 volt power supply and do not need to
use the auxiliary outputs "C" and "D", you can usually use the
auxiliary outputs "C" and "D" to pull up the switch inputs, as shown
here:
[23]
[ H O O K U P C O N E C T I O N S ]
Pin No.
36 18
35 17
34 16
TIE TO COMMON - 33 15
AUXILIARY INPUT - 32 14
PULL UP FOR PIN 10 & 32 - 31 13 - Z AXIS HOME SWITCH INPUT
TIE TO COMMON - 30 12 - Y AXIS HOME SWITCH INPUT
TIE TO COMMON - 29 11 - X AXIS HOME SWITCH INPUT
TIE TO COMMON - 28 10 - LIMIT & PAUSE SWITCH INPUT
TIE TO COMMON - 27 09 - AUXILIARY RELAY "B" OUTPUT
TIE TO COMMON - 26 08 - Z AXIS DIRECTION OUTPUT
TIE TO COMMON - 25 07 - Y AXIS DIRECTION OUTPUT
TIE TO COMMON - 24 06 - X AXIS DIRECTION OUTPUT
TIE TO COMMON - 23 05 - AUXILIARY RELAY "A" OUTPUT
TIE TO COMMON - 22 04 - Z AXIS STEP PULSE OUTPUT
TIE TO COMMON - 21 03 - Y AXIS STEP PULSE OUTPUT
TIE TO COMMON - 20 02 - X AXIS STEP PULSE OUTPUT
TIE TO COMMON - 19 01 - PULL UP FOR PINS: 11, 12, & 13
The value of the pull up resistor will need to be increased to 10K
ohm when auxiliary "C" and "D" are used as the pull up source to avoid
over loading the parallel port. When the auxiliary input on pin 32 is
not used a 4.7K ohm resistor can be connected between pin 31 and pin
10 in place of a 10K ohm resistor.
The home switches are normally open (N.O.) and connect between the
home switch input pins and the common (ground) point. The six limit
switches, and pause switch, are normally closed (N.C.) and are
connected in series between pin 10 and the common point. The bypass
push button for the limit switches is normally open (N.O.) and
connects from pin 10 to the common point. If one of the limit
switches opens (due to out-of-range travel, the motors will stop, and
an error message will come up on the computer screen) press the
[Control] and [X] keys on the keyboard and then press the limit switch
bypass button you wired from pin 10 to the common point. When
installing the limit switches at the home end of the travel be sure
that the limit switches become open several motor steps AFTER the home
switches have closed (otherwise the motors will stop before the home
position is reached!) The WINDOW command in DANCAD3D should be used to
clip the tool path before you save the tool path to an ASCII file to
avoid out-of-range motions.
DANPLOT can be hooked up in some additional configurations. In
order to use the C axis the auxiliary relay "A" and "B" output pins
are used for the C axis step and direction signals, and the auxiliary
input is used for the C axis home switch:
[24]
[ H O O K U P C O N E C T I O N S ]
Pin No.
36 18
35 17
34 16
TIE TO COMMON - 33 15
C AXIS HOME SWITCH INPUT - 32 14
AUXILIARY RELAY "D" OUTPUT - 31 13 - Z AXIS HOME SWITCH INPUT
TIE TO COMMON - 30 12 - Y AXIS HOME SWITCH INPUT
TIE TO COMMON - 29 11 - X AXIS HOME SWITCH INPUT
TIE TO COMMON - 28 10 - LIMIT & PAUSE SWITCH INPUT
TIE TO COMMON - 27 09 - C AXIS DIRECTION OUTPUT
TIE TO COMMON - 26 08 - Z AXIS DIRECTION OUTPUT
TIE TO COMMON - 25 07 - Y AXIS DIRECTION OUTPUT
TIE TO COMMON - 24 06 - X AXIS DIRECTION OUTPUT
TIE TO COMMON - 23 05 - C AXIS STEP PULSE OUTPUT
TIE TO COMMON - 22 04 - Z AXIS STEP PULSE OUTPUT
TIE TO COMMON - 21 03 - Y AXIS STEP PULSE OUTPUT
TIE TO COMMON - 20 02 - X AXIS STEP PULSE OUTPUT
TIE TO COMMON - 19 01 - AUXILIARY RELAY "C" OUTPUT
You still have auxiliary outputs "C" and "D" available if you need
to have control relays and use a +5 volt supply for the pull up
resistors on the switch inputs. So the C axis above hook up can
connect to four motors and two relays.
Another option when hooking up DANPLOT is to use the Z axis
direction bit to control a relay or solenoid rather than a stepper
motor. This option gives you the possibility of two motors and five
relays:
Pin No.
36 18
35 17
34 16
TIE TO COMMON - 33 15
AUXILIARY INPUT - 32 14
AUXILIARY RELAY "D" OUTPUT - 31 13 - Z AXIS HOME SWITCH INPUT
TIE TO COMMON - 30 12 - Y AXIS HOME SWITCH INPUT
TIE TO COMMON - 29 11 - X AXIS HOME SWITCH INPUT
TIE TO COMMON - 28 10 - LIMIT & PAUSE SWITCH INPUT
TIE TO COMMON - 27 09 - AUXILIARY RELAY "B" OUTPUT
TIE TO COMMON - 26 08 - Z AXIS RELAY OUTPUT
TIE TO COMMON - 25 07 - Y AXIS DIRECTION OUTPUT
TIE TO COMMON - 24 06 - X AXIS DIRECTION OUTPUT
TIE TO COMMON - 23 05 - AUXILIARY RELAY "A" OUTPUT
TIE TO COMMON - 22 04
TIE TO COMMON - 21 03 - Y AXIS STEP PULSE OUTPUT
TIE TO COMMON - 20 02 - X AXIS STEP PULSE OUTPUT
TIE TO COMMON - 19 01 - AUXILIARY RELAY "C" OUTPUT
[25]
[ H O O K U P C O N E C T I O N S ]
When using a relay on the Z axis you need to set the default state
for the Z axis direction bit and the rotation of the Z axis motion so
that the relay is off before the tool path starts and is automatically
set off when the tool path ends, by using the configuration setup menu
option number 4. from the DANPLOT and DANCAM main menus. Normally
this means default to logic low and have the Z axis motion -10 to -200
steps. The pulse width factor for the Z axis can be used to control
the delay after the Z direction bit changes before the X and Y motors
start to turn (to allow for the time the Z axis relay/device takes to
respond.)
You can of course use the C axis motor and a Z axis relay if you
want to (three relays and three motors.) You can omit the home and
limit switches if you wish, since both DANCAM and DANPLOT can operate
without the switches connected. The minimum hook up would be:
Pin No.
36 18
35 17
34 16
TIE TO COMMON - 33 15
32 14
31 13
TIE TO COMMON - 30 12
TIE TO COMMON - 29 11
TIE TO COMMON - 28 10 - TIE TO COMMON
TIE TO COMMON - 27 09
TIE TO COMMON - 26 08 - Z AXIS DIRECTION OUTPUT
TIE TO COMMON - 25 07 - Y AXIS DIRECTION OUTPUT
TIE TO COMMON - 24 06 - X AXIS DIRECTION OUTPUT
TIE TO COMMON - 23 05
TIE TO COMMON - 22 04 - Z AXIS STEP PULSE OUTPUT
TIE TO COMMON - 21 03 - Y AXIS STEP PULSE OUTPUT
TIE TO COMMON - 20 02 - X AXIS STEP PULSE OUTPUT
TIE TO COMMON - 19 01
If you wish to connect directly to the pins on your parallel port
card 25 pin connector rather than use the printer end of a parallel
port cable the connections are:
[26]
[ H O O K U P C O N E C T I O N S ]
Pin No.
13 - Z AXIS HOME SWITCH INPUT
TIE TO COMMON - 25
12 - Y AXIS HOME SWITCH INPUT
TIE TO COMMON - 24
11 - X AXIS HOME SWITCH INPUT
TIE TO COMMON - 23
10 - LIMIT & PAUSE SWITCH INPUT
TIE TO COMMON - 22
09 - AUXILIARY RELAY "B" OUTPUT
TIE TO COMMON - 21
08 - Z AXIS DIRECTION OUTPUT
TIE TO COMMON - 20
07 - Y AXIS DIRECTION OUTPUT
TIE TO COMMON - 19
06 - X AXIS DIRECTION OUTPUT
TIE TO COMMON - 18
05 - AUXILIARY RELAY "A" OUTPUT
TIE TO COMMON - 17
04 - Z AXIS STEP PULSE OUTPUT
AUXILIARY RELAY "D" OUTPUT - 16
03 - Y AXIS STEP PULSE OUTPUT
AUXILIARY INPUT - 15
02 - X AXIS STEP PULSE OUTPUT
14
01 - AUXILIARY RELAY "C" OUTPUT
You can of course adjust connections on the 25 pin connector to
correspond to any of the alternate hook-ups, e.g. use auxiliary input
on pin 15 for the C axis home switch, and or use the auxiliary relay
"D" output on pin 16 to pull up pin 10. As you have probably noticed
pins 1 through 13 have the same connections on both the parallel port
25 pin connector and the 36 pin parallel printer cable connector.
[27]
[ C O N F I G U R E A N D I N S T A L L ]
CONFIGURE AND INSTALL
DANCAM and DANPLOT send messages to the motor translator modules
in the form of what are called "steps". The motor shaft rotation is
divided into fractions, usually 1.8 degrees per step, or 200 steps per
360 degrees (360/200=1.8). Sometimes motors are run "half step" mode
where the step is divided in half, e.g. 400 per revolution of the
motor shaft. Micro stepping divides the motor step into smaller
parts, but does not usually offer higher actual possitional accuracy
under fluctuating loads since the motor shaft of a stepper motor will
typically exhibit 0.9 degrees of possitional error when driven under
full load from clockwise, and then counter-clockwise rotation. For
servo motors the shaft encoder defines the minimum rotational interval
or "step."
Note that the unit name inches is given in the configuration menus
in DANCAM and DANPLOT even though any units can be used so long as all
of the set up is done in the same units of measurement. This was done
to avoid the confusion some users have about the meaning of the word
units. You will also have to set the overall scaling factor in the
configuration menu of DANCAM and DANPLOT to relate to the units
scaling factor used while drawing the tool path in DANCAD3D. If this
gets confusing, just set the global scale in DANCAD3D at 240 and
configure DANCAM and DANPLOT in steps per inch, and set the DANCAM -
DANPLOT overall scaling factor to 1 (then one unit in DANCAD3D's
drawing editor will move the tool one inch (this is the default
configuration.))
So since the motor shaft has finite positions that it can stop at,
the driven load will also have finite positions it can stop at. When
working out the ratio of the timing belt pulleys for the motor and
lead screw you should figure that one motor step should move the work-
piece relative to the tool by one half the smallest amount necessary.
If you are machining to 0.001 of an inch and have a 10 pitch lead
screw then 1:1 coupling of the stepper motor will give you 0.0005
inches of movement per motor step, i.e.:
200 steps per revolution
-------------------------- = 2000 steps/inch = 0.0005 inches/step
0.1 inch per revolution
Successfully installing DANCAM or DANPLOT requires having the
motors installed to give the coarsest resolution that will be
acceptable. Excessively fine resolution will limit the maximum speed
the tool can move (because the steps per second is constant.) Reducing
the resolution will increase the maximum speed the tool can travel.
In our example we can calculate the maximum tool feed speed in inches
per minute from the motor RPM, since with 1:1 drive the tool will move
0.1 inch per revolution, and 120 RPM would be a reliable maximum speed
for the motor shaft.
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[ C O N F I G U R E A N D I N S T A L L ]
120 revolutions per minute
-------------------------- = 12 inches per minute
10 revolutions per inch
Feed rates for other resolutions can be worked out for the motor
shaft speed of 120 RPM and 1:1 shaft coupling:
LEAD SCREW FEED/REV STEPS/INCH INCH/STEP INCHES/MINUTE
2.5 tpi 0.4" 500 .002 48
5.0 tpi 0.2" 1000 .001 24
10.0 tpi 0.1" 2000 .0005 12
20.0 tpi 0.05" 4000 .00025 6
Since the torque of stepper motors falls off the faster the motor
turns you may only be able to get reliable operation at speeds slower
than 60 RPM. In general doubling the voltage used to drive a stepper
motor will increase the top speed by 50%, i.e. if a motor works well
at 60 RPM at 24 volts you can probably get it up to 90 RPM by
increasing the voltage to 48 volts. The top voltage for stepper
motors is about five times the rated voltage, you will of course need
to limit the current to the rated current to avoid burning out the
motor (in the simplest scheme a series power resistor is used to limit
the current flowing through the motor winding when the motor is not
turning to the rated current, because the motor is an inductive load
the resistor will allow the voltage to rise briefly at the beginning
of each motor step before the voltage drops back to the static level,
thereby making the motor turn faster.)
When building a plotter you can drive the pen holder by using a
timing belt driven directly by a pulley. Small motors can generally
run at 240 RPM in half step mode to give 1600 (half) steps per second.
PULLEY DIAMETER FEED/REV STEPS/INCH INCH/STEP INCHES/SECOND
0.25" 0.785" 509.55 0.00196" 3.14159"
0.50" 1.570" 254.65 0.00392" 6.28318"
0.75" 2.356" 169.76 0.00589" 9.42477"
0.10" 3.141" 127.32 0.00785" 12.56636"
When selecting stepper motors to drive your equipment you should
use motors that have a rated holding torque AT LEAST FOUR TIMES the
torque that will be required under load and at full speed. Also use
the motor testing utilities built into DANCAM and DANPLOT to do the
start and stop test to make sure that the spacing of the pulses sent
to the motor translator module are far enough apart (a larger pulse
[29]
[ C O N F I G U R E A N D I N S T A L L ]
width factor will space the pulses wider apart) for the motor to keep
up with the step pulses (if the pulses are to fast the motor will not
come back to the point it was at at the beginning of the motor test,
indicating unreliable operation.) The ramping should be set to 0 when
testing stepper motors.
I would like to warn you that stepper motor manufactures published
speed v.s. torque curves can be very optimistic, and are not generally
applicable to use with DANCAM or DANPLOT. As a rule of thumb based of
my experience you can expect these values for maximum top speeds for
reliable error free operation under working load, with the higher RPM
number being obtained by using the maximum voltage the motors can take
(when the voltage is more than six times the rated voltage stepper
motors may become unstable in the middle of the motors speed range, so
you are limited in how much the motors can be boosted):
MOTOR HOLDING TORQUE MAXIMUM MOTOR SHAFT SPEED
20 - 40 in/oz 240 - 300 RPM
40 - 150 in/oz 120 - 240 RPM
150 - 400 in/oz 90 - 120 RPM
400 - 1500 in/oz 30 - 90 RPM
To configure DANPLOT and DANCAM to produce the proper number of
steps per inch of travel simply run DANCAM or DANPLOT from DOS and
select mode #4 from the main menu that comes up. Since stepper motors
typically can only step 300 to 1000 full steps per second (600 to 2000
half steps) the motor step delay of 0.5 ms to 3 ms is needed to keep
the motors working properly. The minimum motor single step delay is
controlled a value called the pulse width factor (p.w.f.). Each axis
has its own p.w.f so the motors can run as fast as possible
(allowable) when the maximum feed rate is requested.
When you install DANCAM and DANPLOT using their main menu option
#4, be sure to work through the sub-menu options in order 1,2, (sub-
menu of 2 options 1,2,3 for each axis) and then 3,4, and 5.
When you work through the menus keep in mind the number of steps
the motor shaft makes per revolution. If you run a motor in half step
mode then multiply the number of motor steps by two. For servo motors
the number of steps per revolution can be derived from the encoder
counts per revolution and any pulse rate multiplier used.
In the motor test sub-menu (#2 in the configuration menu) use
option #1 to find the smallest p.w.f. that makes the motor run
smoothly under load, use #2 (of #2 of #4) to check that the motor is
not missing any steps (make the p.w.f. larger if the motor is missing
steps and test again), and use #3 (of #2 of #4) to test the RPM if
needed. When the p.w.f. has been configured for each axis press [Esc]
to go back to the installation sub-menu and answer the other
questions. The ramping should be set to 0 for testing stepper motors.
[30]
[ C O N F I G U R E A N D I N S T A L L ]
The questions in option #3 in the installation sub-menu should be
used to install the scaling factors before you enter the feed rate
controlling delays with option #4. In this version of DANPLOT and
DANCAM the feed rate is controlled by a delay between motor steps.
Since the p.w.f. keeps each motor working properly the feed rate delay
can vary from 0 to 65000000 micro seconds per step depending on how
slow you want the feed. To get different feeds, enter the delays you
want in the feed rate table, then make the tool path drawing with
DANCAD3D so that the line segments have the color attribute that
corresponds to the delay set in the feed table. The line color
attribute is set while drawing in DANCAD3D v2.5 by pressing the [L]
key of the keyboard or by using the mouse to click on the with [L]ine
style option of the [L]ines sub-menu from the drawing editor root
menu. Any step delay value can be assigned to any line color number.
Set all the delays to 0 if you want the tool to move as fast as
possible for all motion.
Another configuration menu option lets you assign which line
colors will turn on or off the auxiliary control relays. Line
segments used to control the auxiliary relays can have starting and
ending points at the same location (i.e. zero length.)
Option #5 of the installation sub-menu asks about the home
switches. Both DANPLOT and DANCAM let you install home switches on
your equipment so that you can have the tool automatically home up
before each tool path file is read. The ability to home up
automatically can be a great time saver. You should note that without
the use of the switches to home up, an error of +/- 3 full motor steps
can occur when DANPLOT and DANCAM are first run since the motor rotors
will jump to the position dictated by the mechanical relationship of
the motor rotor and the state of the motor winding sequence that the
motor controller starts with. Most stepper motor controllers start
with the same coil (phase) energizition pattern, so you can loosen the
motor coupling, reboot your computer, re-run DANPLOT or DANCAM and
tighten the motor coupling with the tool carrier at it's home
position. Lousing, rebooting the computer, and tightening the motor
coupling will not help if the motor controller initializes with a
random energizition of the motor windings, in such a case you would
have to use the home switches or manually check to see if the motors
shafts have an incorrect position and use main menu option #3 to get
the motor shafts into the proper starting orientation.
DANPLOT has some additional special configurations. The "C" axis
lets you mount a fourth motor with its shaft parallel to and centered
on the Z axis such that a knife, saw, or broach will automatically
rotate to point the cutting edge into the motion of travel. The
tolerance on the C axis lets the tool stay down while cutting out
curves. The manual up and down option lets you manually activate the
Z axis for use in automating a drill press with two motors (one for X
axis and one for Y axis.) In manual up/down mode the work-piece is
positioned and then the computer is made to pause while you drill the
hole, then you press a key on the keyboard and the work-piece will
[31]
[ C O N F I G U R E A N D I N S T A L L ]
move to the next position, and so on.
[32]
[ D R A W I N G T O O L P A T H F I L E S ]
DRAWING TOOL PATHS WITH CUTTER TOOL COMPENSATION
The following are the steps required to draw a tool path element
while being able to visually see the shape of the cutter on the
computer screen. Please read the file DANCAD3D.DOC on the DANCAD3D
v2.5 program disks and read the menus in the DANCAD3D program drawing
editor to learn more about what these steps mean.
NOTE: You will need DANCAD3D v2.5H or later to draw cutter paths with
compensation for the cutter shape.
1. Run the DANCAD3D program. Press [Return] until you reach its main
menu.
2. Select [D]raw from the DANCAD3D main menu. Select the [F]ront
view. If the drawing workspace is not empty select [I]nitialize
to clear the workspace.
3. Select [D]raw from the drawing editor root menu. Draw an outline
of the shape of the finished work-piece you wish to make. You can
make the inside corners sharp if the radius will be determined by
the cutter shape. You can make the shape outline in 3D if you are
going to do 3D work. Remember that lathes are 2 axis devices, so
the tool path for the lathe will be 2D (i.e. a profile.) You can
include an outline of the raw material in the outline of the
finished piece to make visualization of the amount of material to
remove easier. The outline of the work-piece can include outlines
of holding fixtures and other machine parts so that you can check
for interference with the cutter.
4. The next step is to make an outline for the cutting tool. If you
are going to use an end mill you can use the [P]olygon command
(try to keep the sides total to 36 or less) in the 2D shapes
drawing editor sub-menu. For other shape cutters press [B] to
begin a new element (element 2) and draw the outline of the
cutter. The center of the cutter outline element should be on the
cutter's axis of rotation if the cutter rotates. The cutter
outline can be 3D and include the tool holder or tool post so that
you can visually check for interference with the work-piece or
other parts of the machine.
5. To draw the actual tool path element go into the drawing editor's
[E]lements sub-menu and select [D]rag. Select [E]nter element
number and enter the element number for the cutter outline
(element 2.) Select the element center as the reference point.
Press [Return] to start the drag command. The cutter outline will
blink. Press [B]egin element to begin the tool path element (the
tool path will be element number 3.) Move the cutter outline to
the home position with the [G]oto drawing command. Use the mouse
to position the cutter outline near the edge of the raw material.
Press the left mouse button to draw the first line segment in the
tool path. Move the mouse for the path of the first cut and press
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[ D R A W I N G T O O L P A T H F I L E S ]
the left mouse button again. Continue drawing zig-zag,
concentric, or spiral tool path until the blinking outline of the
cutter comes in contact with the outline of the final shape. When
drawing tool paths be sure that you only feed the amount that can
be safely taken off (so the tool will not stall or break!) Also
remember that some cutters can only cut going one way, so you may
have to retrace without feed when drawing in one direction.
Pressing [L] while inside the [D]rag command will let you change
the drawing line color, and therefore set the feed rate, auxiliary
relays, and programed pause.
6. When the tool path is finished press [Escape] to exit the [D]rag
command. [Q]uit the drawing editor and select [F]iles [S]ave
[A]SCII from the main menu. Enter the element number for the
element of the tool path (normally element 3) as the element to
save.
7. Make a trial part using DANPLOT or DANCAM.
8. Measure the trial part. Record any error in the final shape.
9. Load the tool path ASCII file into DANCAD3D and use the [P]ull-
Point command in the [L]ines sub-menu of the drawing editor to
alter the tool path line segments for the final cut, in order to
correct the error. Save the corrected tool path element again as
an ASCII file.
10. Repeat steps 7 to 9 if needed until the finished part is in
tolerance. Make the run of parts as needed. Store the ASCII tool
path file on a floppy disk for future use. You should also copy
the DANPLOT.CFG or DANCAM.CFG file used to make the part onto the
floppy with the tool path so the tool path will match up if used
again. You should also file notes about the spindle speed and
cutter seating used and also the location of the limit switches
relative to the work-piece.
If you want to change the line color attribute for any of the line
segments in the tool path such as the line segment for the final cut
you can use the commands in DANCAD3D's drawing editor [L]ines sub-
menu. The conversion of the line color attributes in the tool path
data file to feed rates is done using the values for the step delay
that you have entered into the DANPLOT and DANCAM feed rate table
(option #4 in the DANPLOT and DANCAM installation sub-menu.)
You can also draw the bulk of the tool path in the drawing editor
[D]raw lines sub-menu and then go into the [D]rag command in the
[E]lements sub-menu to align the cutter outline to the final shape
outline for the last few cuts. If you want to add line segments to
the tool path element that you started in the [D]raw lines sub-menu
use the [D]rag command as described above in step 5. but select
command [E]lastic line in place of [B]egin element.
When you need to use commands that create new elements such as the
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[ D R A W I N G T O O L P A T H F I L E S ]
[P]olygon command, or the [F]it-curve in DANCAD3D's, you can unite
later the elements created into a single ASCII file by erasing the
finished part outline, and the tool outline from the workspace, then
use element 0 as the element to save rather than element number 3.
The [J]oin command in DANCAD3D's drawing editors [E]lements menu can
also be used to unite elements into a single tool path element.
[35]
[ R U N N I N G T H E C A M D E M O F I L E S ]
RUNNING THE DEMO FILES FOR DANPLOT AND DANCAM
A demo is provided for each program. Enter DEMOPLOT.BAT from DOS
with the prompt indicating the drive and directory all the DANPLOT
files are in. DEMOCAM.BAT does the same for DANCAM.
EXAMPLE: C>DANPLOT DANPLOT.ASC 1
You can interrupt the motion of the motors momentarily by pressing
the [P] key, press [P] or [SpaceBar] to restart the motors. If you
need to touch or otherwise expose yourself to the equipment while the
motors are paused from the keyboard you should also use the pause
switch wired in series with the limit switches (as shown on drawing
HOOKUP1.ASC) and turn off the motor power (if your translator module
will re-initialize when the motor power is cut off you will have a
problem (because the motors may jump when the power is switched back
on), the circuit schmatics I provide with the DANCAD3D user outfit for
the stepper motor translator allow the translator logic to stay
powered while the motor coil (phase) power is switched on or off
thereby avoiding any motor jumping.)
You can load the example *.ASC tool path files into DANCAD3D to
look at how they were drawn. DANCAD3D's main menu [P]review command
will let you rotate the display of the tool path's line segments so
you can see the spatial relationships.
[36]
[ H E L P W I T H D A N C A M A N D D A N P L O T ]
HELP AND FEEDBACK
If you have any questions or comments about DANCAM or DANPLOT feel
free to write me at:
ADDRESS: DAN HUDGINS
c/o DANCAD3D CNC
466 DIAMOND STREET
SAN FRANCISCO, CA 94114
The UNITED STATES of AMERICA
When you write PLEASE enclose some stamps for the replay postage.
If you live outside the U.S. you can get some postal vouchers for
first class international air mail postage from your post office.
More information and schematics for wiring up inexpensive motor
driver modules is included in the DANCAD3D user outfit. I can help
you design custom hardware special applications.
If you need help in locating stepper motors, drivers, and other
mechanical and electronic components feel free to contact me for help
in locating just what you need. I am always on the look out for parts
that are at the lowest cost.
If you would like to discuss something on the phone I can call you
collect if you send me a letter telling me what time to call and
asking me to call collect (sorry but collect calls cannot be made to
Germany.) I can call on evenings or weekends if you prefer, but be
sure to tell me what days and times I should call.
I am always working on a improvements to the programs and
documentation. If you register with me by sending one dollar and your
full name and address I will put your name on my user mailing list.
If you are using DANCAM or DANPLOT at all you will benefit from
communicating with me directly. If you have a machine hooked up I
would be most appreciative if you could send me a photo of what you
have built, I always enjoy seeing what users are doing with the
programs.
Feel free to send me your "wish list" for DANCAD and DANPLOT
improvements. Although "G" codes are not needed since DANCAD3D makes
tool paths graphically I may write a "G" code converter if enough
users ask for me to write one. If you are interested in "G" codes
send me a "G" code file on a floppy disk so I can see the type of file
you need.
[37]