** == **› INSTALLING A COOLING FAN ON YOUR DISK› DRIVE  -  A DIFFERENT VIEW! (Excerpts› from a letter by BEN POEHLAND  Editor› of ATARI CLASSIC to Ron Fetzer.)›› (Editor, The article  BEN  refers  to› was printed before BEN's response was› received, but so that both views  are› given, this is being printed. You are› on your own as to what you decide  to› do.   See  Jan/Feb  1994  OL' HACKERS› newsletter for the  original  article› to which B. P. is reponding.)›› A FAN FOR THE 1050 DRIVE?›      ...The problems I have with your› article   (upgrade)  are  more  of  a› philosphical    nature.    ...    I'm› philosophically opposed to  the  idea› of  adding fan cooling to disk drives› generally. And, although the  additon› of a fan is conceptually a good idea,› you can end up doing more  harm  than› good  in the long run if you don't do› it right. Let me explain.›› FANS SHOULD RUN COOL.›       First   off,   a   disk   drive› (especially  a 1050) that runs hot is› probably defective. ...I'm  rather  a› staunch  believer  in curing problems› at the source  rather  than  applying› band-aids.  Some  1050 run abnormally› hot because certain repair  companies› installed  underspec'd  rectifiers in› the charge-pump circuit of the  power› supply.  The  cure  is to replace the› diodes, not carve  up  the  drive  to› install  a  fan. Replacing the diodes› is a  lot  cheaper,  too  (the  high-› current diodes are available at Radio› Shack).›› NORMAL HEAT!›      It's normal for the heatsinks in› the  Atari  drives  to  get hot. They› serve to keep the voltage  regulators› at a steady-state temperture. As long› as the regulators don't get so hot as› to  trip   their   thermal   shutdown› circuits, the drive is OK.›      In  most  Atari drives there's a› power   transistor  attached  to  the› regulator heatsink.  This  transistor› provides  current  to the drive motor› in the mechanism. If there is a fault› in  the mechanism or a defective disk› or   someone   operating   the  drive› irresponsibly, this  transistor  will› pass  excess  current and heat up the› heatsink. ...›› CURING THE PROBLEM!›      Again, you cure the  problem  at› the  source:  don't use crummy disks,› repair the mechanism, or correct  the› operator's  sloppy  habits (impatient› people flipping the latch  while  the› drive  light  is  on  is  a   typical› case).›      ...Cheap disks can cause spindle› motors (and heatsinks)  to  run  hot.› There's a simple test you can perform› to detect one of these nasty buggers,› I  call it the "two-finger test". You› stick your index and  middle  fingers› into the hub hole of the disk. Spread› your fingers slightly until the  disk› is  securely  held.  Then  rotate the› diskjacket with your other  hand.  It› should  turn  easily.  If it doesn't,› trash that  disk,  it  has  too  much› internal  friction  ...  My  favorite› disks are the Verbatim Datafile Plus.› Their jackets are  internally  coated› with teflon, they pass the two-finger› test easily and  work  flawlessly  in› all drives ...›› WHEN TO USE A FAN!›      About  the  only justification I› can see for adding fans to drives  is› if  you live in a hot climate and use› the drive for more than 3  hours/day,› or  if  you  live  in  an  area where› chronic overvoltage (above 130VAC) is› a  problem (very rare!)... Once a fan› is installed you are  moving  massive› volumes of air through the case, much› more  than  by  ordinary  convection.› Consequently,   you  are  now  moving› massive  amounts  of  dirt  into  the› case. The air leaves, but most of the› dirt  stays  behind.  Bad  news! Dirt› does two bad things. First, it  coats› individual  electonic components with› an  insulating  layer  that  inhibits› their ability to dissipate  heat,  so› you  actually  increase the potential› for failure at the  component  level.› Second (and even worse), on damp days› dirt   conducts    electicity.    The› electronic  effects are variable, but› typically act to  introduce  unwanted› capacitance,  change  the  value   of› resistors  by   providing   alternate› current  paths  and  distort  dynamic› signals  by  partly  rectifying  then› (diode action). Such drives behave as› if they were inhabited by demons.›› HOW THE FAN AND A FILTER CAN BE USED!›       In  electronic  equipment,  you› ALWAYS   install  a  fan  in  such  a› fashion that  is  draws  outside  air› into at the fan location and create a› positive pressure differential inside› the  case.  The fan intake opening is› then covered with a  suitable  filter› to  ensure  the air entering the case› is free of gross  particulate  matter› (submicron particulates exit the case› with   the   exhaust  air  so  aren't› usually a problem). ... These filters› are  sold  at  most  electonic supply› houses.   I  get  them  for  $.95  at› American  Design  Components  in  New› Jersey. You can get  them  to  fit  a› standard  3.5  muffin  fan  ...  I've› developed  the  trick of deliberately› installing   the  filters  backwards.› This permits  you  to  snap  out  the› plastic  grille so you can remove and› wash   the   filter  element  without› opening up the case.›      Installing  a  negative-pressure› fan  (fan  sucking  air  out  of  the› case)is   as   bad   as   installing › positive-pressure   fan   without   a› filter...  In such condition you have› no control  over  airflow  direction,› and   it's   impossible   to   filter› incomming    air.    Most    IBM-type› computers are cooled this  way.  Like› most IBM things: Bass-Ackwards.›› THE INDUS DRIVE.›      Your  (RON  FETZER's)  idea   to› increase  convection  cooling  in the› Indus was more to my liking  but  not› well  implemented.  Much  simpler  to› just  pencil  a  gird on the case and› drill a bunch  of  closely-spaced  #4› holes,  followed  by deburring with a› drillstone and covering with a  piece› of screen held in place on the inside› by a bead of silicone adhesive. ... I› question  whether  the  rather  large› hole  you  described for the Indus is› really necessary.›› USE OF OIL---- HORRORS!›      Finally, I recoil at your advice› to  apply  sewing  machine oil to the› head   rails.   NO,  NO,  NO!  Liquid› lubricants   must  NEVER  be  applied› there! Or anywhere inside a drive for› that matter.›      There  are  two   problem   with› liquid    lubricants.   First,   even› assuming you put it  where  you  want› it,  it  doesn't  stay there. Liqulid› lubricants migrate, especially in the› warm  invironment  of  a  drive case.› Sooner or later it ends up where  you› don't  want it. And second, sooner or› later     all    liquid    lubricants› evaporate/polymerize,   depositing  a› gummy   residue  that  inhibits  head› movement. This gummy polymer  residue› junk is nasty to clean off.›      The correct type of lubricant to› use is a lightweight silicone grease.› CSS  sells  a  product   called   the› "Silencer"...My  standard, that I use› computer/electronic    lubricant   is› "Lube-Gel". It comes in  a  tube  for› $6.00  at   Radio   Shack.(#64-2326--›  $2.49  -- RON)... one tube will last› several liftimes, you can pass it  on› to  your  grandchildren  as  part  of› their  inheritance. It's a chemically› stable  slilicone-base  clear  grease› containing microparticluate  emulsion› of teflon.›› HOW TO:›       The    application    techingue› requires  breaking  a  wooden   Q-tip› handle  so  you  can  get a nice thin› sliver of  wood  (Radio  Shack  sells› wooden  - handled Q tips.) Using this› sliver, ... apply tiny amounts of the› grease to practically any location in› the  drive.  The  rails  have  to  be› greased on the sides and  the  bottom› as well as the top. The cotton end of› the   swab  is  used  to  remove  any› excess. The stuff stays where you put› it,  doesn't  migrate,  evaporate  or› polymerize.  I  also  use  it  on the› drive latches and the  disk  ejection› mechanism;  some  drives  turn   into› "disk  cannons"  after the treatment.› Lube-Gel is also  great  for  printer› mechanisms,  especially the head bars› on the 1027.›› MY OPINIONS.›       As  you  can  see,  this  is  a› subject in which I have quite  a  bit› of experience and, consequently, some› rather  strong  biases.  I  certainly› won't say the advice in your  article› is    incorrect:    only    that   it› contradicts so many of my own  biases› that it would bother my conscience to› print it.›      Warmest regards,›      Ben Poehland›››               >> <> <<› RON FETZER replies:››      I  have  used the disk drives as› described in the article of the OHAUG› NEWSLETTER of JAN/FEB 1994 for over a› year without any trouble.›       The   advice   BEN   gives   is› wothwhile.  I  will  limit the use of› the   fans   only  during  long  copy› sessions. And finally I will use ONLY› "LUBE-GEL" inside the drives.›       The    INDUS     disk     drive› modification  that  BEN   suggests is› also much easier to do.›      I thank  BEN  POEHLAND  for  the› many great suggestions and worthwhile› procedures   and   for  reviewing  my› article. (Ed. Thanks for both views!)›› >>>>>>>>>>>>>>>>END<<<<<<<<<<<<<<<›