NetNews Usenet Archive 1992 #27

home *** CD-ROM | disk | FTP | other *** search

/ NetNews Usenet Archive 1992 #27 / NN_1992_27.iso / spool / rec / models / rockets / 3060 < prev next >

Wrap

Text File | 1992-11-21 | 37.1 KB | 767 lines

Newsgroups: rec.models.rockets Path: sparky!uunet!seas.smu.edu!vivaldi!rsd0!rsd.dl.nec.com!buzz From: buzz@rsd.dl.nec.com (Buzz McDermott) Subject: Frequently Asked Questions - Part 1 of 5 Message-ID: <1992Nov21.171959.498@rsd0.rsd.dl.nec.com> Keywords: FAQ Lines: 753 Sender: usenet@rsd0.rsd.dl.nec.com Nntp-Posting-Host: rsd2.rsd.dl.nec.com Organization: NEC America, Radio Software Dept Date: Sat, 21 Nov 1992 17:19:59 GMT Expires: Sat, 19 Dec 1992 15:00:00 GMT Rec.Models.Rockets FAQ (Frequently Asked Questions): Part 1 of 5 Last Modified: 20 Nov 1992 This FAQ will be posted approximately once a month. *** PART 1: INTRODUCTION AND GENERAL INFORMATION Part 1: Introduction and General Information Table of Contents Introduction to r.m.r and This FAQ Section 1.1: Glossary Section 1.2: Some Commonly Sought Addresses Section 1.3: Other Sources of Information Part 2: Model Rocketry Section 2.1: Model Rocketry Questions Section 2.2: Born-Again Rocketeers Section 2.3: Scale Modeling Section 2.4: Construction and Finishing Tips Part 3: High Power Rocketry Section 3.1: On To High Power Section 3.2: Construction and Finishing Tips Section 3.3: Ignition and Launch Systems Tips Section 3.4: Large Rocket Glider Construction Tips Part 4: Payloads Section 4.1: Camera Payloads Section 4.2: Data Gathering Payloads Section 4.3: Bio-payloads Section 4.4: Novelty Payloads Part 5: Competition Section 5.1: Summary of Events and How to Get Started Section 5.2: Competition Tips and Strategies Section 5.3: Some Model and High Power Rocketry Records ---------------------------------------- Introduction to Rec.Models.Rockets and This FAQ Rec.models.rockets (r.m.r) is a Usenet newsgroup oriented towards discussions and topics related to non-professional rocketry of all types. All questions, comments, and ongoing discussions related to non-professional rocketry are welcome. This FAQ (list of Frequently Asked Questions) is an attempt to compile a number of questions and suggestions that have been repeatedly posted to r.m.r into a single, quickly readable document. This document is NOT a 'how to' on any form of non-professional rocketry. It's hoped that it might be of use in answering some of the more commonly asked questions, summarizing some good tips and suggestions, and directing the reader to other documents, books, sources, etc., where more information may be found. It is organized as a list of primary topics (see the Table of Contents) with a number of questions and answers under each. The majority of this document deals with, but is not limited to, consumer rocketry in the United States and Canada. This document was originally compiled (with much help from many others) by Buzz McDermott. He would like to thank all those who contributed and helped with this FAQ. Special thanks goes to Jack Hagerty, who has acted as both an excellent editor and major contributor to the contents of this document. Jack is now also the editor of Part 4, Payloads. Comments, corrections, suggestions for improvements and new ideas for this FAQ may be mailed to buzz@rsd.dl.nec.com. All comments and suggestions (both good and bad) are welcome and encouraged. Many of the rocket manufacturer and mail order house addresses in this document were originally obtained from the 'List of rocket manufacturers and organizations (Updated Nov 1992)', maintained by R. M. Jungclas. ---------------------------------------- Section 1.1: Glossary The following are some commonly used abbreviations, terms, and acronyms used within r.m.r. These definitions have come from many contributors. Thanks to all for their help in building this glossary. advanced see 'high power rocket' rocket AmSpac Abbreviations for "American Spacemodeling", the journal of AmSpam the National Association of Rocketry. amateur rocket The class of non-professional rocket beyond HPR. Amateur or rockets use structural metal parts and very often the motor experimental casing doubles as the airframe (as with professional rockets). rocket These rockets can be very large and powerful, capable of placing payloads many miles up. Activities in this field (one can scarcely call it a hobby) include formulation and manufacture of fuels and thus can be *extremely* hazardous. This is the main reason that amateur rocketry is not to be attempted alone. Another is expense as these vehicles can run many hundreds or thousands of dollars and take months to build. The equipment necessary to safely pursue amateur rocketry (sandbagged bunkers, loading pits, standby fire truck, etc.) are quite beyond the resources of individuals. The Black Rock Society and Pacific Rocketry Association are two amateur rocketry organizations. Not all amateur rockets are so large. Many of the "beginner" vehicles would qualify as HPR or even model rockets in terms of liftoff weight and total impulse, but fail the NAR/Tripoli codes due to their metal airframes and user-compounded propel- lants. Note: There is a fine, but significant, difference between using a metal cased reloadable motor with pre-manufactured fuel slugs and stuffing a pipe with zinc/sulphur (a common amateur beginner fuel). Neither the NAR nor Tripoli sanction amateur rocket activities. B/G Boost glider. A glider which is boosted to altitude by a rocket motor. The pod containing the expended motor may separate from the glider at ejection to be returned by streamer or parachute (this is typical but is not required). The more aerodynamically clean glider section is then free to glide more slowly. BAR Born Again Rocketeer. An individual who has rediscovered the hobby/sport after an absence of several years. black powder Basically, gunpowder. The 'traditional' model rocket motor fuel. Used by Estes, Quest, FSI, and most other model rocket motor through D power. FSI has black powder motors through F (and maybe, G) power. CA Cyanoacrylate ('super glue'). A very strong adhesive popular for use in competition and high power rockets, as well as 'on the field' repairs. The three most common forms of CA are often referred to as 'hot', 'gap filling' and 'slow'. Hot CA is very thin and has strong wicking properties. It dries in only a few seconds. Gap filling CA is a little thicker and generally comes in 15 - 30 second bond times. Slow CA forms the strongest bond but its bond times are also much longer. Hot or gap filling CA is often used to tack parts into place prior to applying a stronger adhesive with a much longer bonding time (such as an expoy). CATO a motor failure, generally explosive, where all the propellant is burned in a much shorter time than planned. This can be a nozzle blow-out (loud, but basically harmless), an end-cap blow-out (where all of the pyrotechnic force blows *forward* which usually does a pretty good job of removing any internal structure including the recovery system) and finally, a casing rupture which has unpredictable, but usually devastating, effects. Another form of CATO is when there is a motor delay train or ejection failure. This may be caused by either the delay train failing to burn or the ejection charge not firing, but the result is the same: the model prangs. Opinions on the meaning of the acronym range widely. Some say it's not an acronym at all, but simply a contraction of 'catastrophic' and should be pronounced 'Cat-o'. Others maintain that it is an acronym but disagree on the meaning, offering both 'Catastrophic Take Off' and 'Catastrophically Aborted Take Off'; the latter, at least, uses all the letters. Either of these are usually pronounced 'Kay-Tow', like the Green Hornet's side kick. A CATO does not necessarily burn all of the fuel in a rocket motor. This is especially true for composite fuels, which do not burn well when not under pressure. For this reason you should be especially careful when approaching a CATO. Opinions on the origins say that it is either from the military rocket programs of WWII, the post war development era, or even a modroc-only term which originated with the MESS (Malfunctioning Engine Statistical Survey) performed at NARMIT. CG Center of Gravity. The point about which a free body will rotate when disturbed by an outside force. For a model rocket, this is the point where the model balances with exactly half its mass on either side. composite The term used broadly to cover solid fuel rocket motor using other than black powder. Composite motors require different ignitors and ignitor systems from black powder motors. core sample Synonyms describing a failure mode where the model comes down tent peg fast and hard (nose first) and ends up tail-high in the ground lawn dart (this is where large, colorful fins come in handy :-). Often the nose cone has separated (taking the recovery device with it) and the model body tube ends up containing a nice 'core sample' of mud/dirt when pulled out of the ground. CP Center of (Aerodynamic) Pressure. The point on a rocket where stability-restoring forces due to airflow against the back part of the rocket (fins, etc.) exactly equal the disturbing forces due to airflow against the part of the rocket ahead of that point. The location of this point depends on how much the rocket's orientation is disturbed at the time of measurement. If it is at a very small angle to the "local wind" (line of flight), the fins' restoring contribution will be large, while the nose's disturbing contribution will be small, resulting in a CP that is way back. The CP in this case can be located using the Barrowman Equations. If the rocket is nearly sideways, the CP will be much more forward. The CP in this case can be located by balancing a cardboard silhouette of the rocket. Since all free bodies can rotate only on their center of mass, stability is usually a simple matter of ensuring that your CG is ahead of your CP, which ensures that the restoring forces of airflow on the rear of the model will always overcome the disturbing forces on the front. A good rule of thumb for sport models (both high and low power) is to design the rocket with the CP one or two body diameters behind the CG. CPSC Consumer Product Safety Commission. The government agency which has the task of deciding whether or not a given product is safe for 'general consumer' use. DQ Disqualified flight. engine A machine that converts energy into mechanical motion. Such a machine distinguished from an electric, spring-driven or hydraulic motor by its consumption of a fuel (from _American Heritage Dictionary_). (FIRE)BALLS an annual experimental rocketry launch where emphasis is on VERY LARGE advanced rockets. high power a non-professional rocket weighing more than 1500 grams rocket at liftoff, containing more than 133 grams of propellant, or or containing any motor with more than 160NS of advanced total impulse. High power motors go all the way to class 'O', rocket with over 40,000NS of total impulse. High power rockets require an FAA waiver to launch. Tripoli defines a high power rocket as those with over 40NS of total impulse (i.e., 'F' power and above) and advanced rockets as those with more than 160NS total impulse (i.e., 'H' power and above). HPR High Power [Rocket(ry)]. See 'high power rocket'. HPR 'High Power Rocketry Magazine', formerly 'Tripolitan... Magazine America's High Power Rocketry Magazine'. An independent magazine dealing with all aspects of consumer rocketry, but with a definite emphasis on high power, advanced and experimental consumer rocketry. See section 5 for address. land shark A rocket which has failed in such a way that it ends up on the ground while still under power. Upper stages of unstable multi-stage rockets often end up like this, as due some (too) heavy HPR rockets with long-burning, low thrust motors. LDRS The annual national high power sport launch sanctioned by Tripoli. The 1992 LDRS (XI) will be held in the Black Rock Dessert, NV., the week after NARAM. LDRS reportedly stands for 'Large Dangerous Rocket Ships'. Lovelace A phenomenon where the nose cone is apparently "sucked" out of Effect the body after motor burnout, but well before the expected ejection. It is more prevalent on parabola, ogive and other low drag nose shapes. The theory (as yet unproven) is that since the nose cone has much less drag than the body, its momentum tends to carry it forward faster (or, more correctly its lower drag decelerates it more slowly) than the body putting tension on the nose-body joint. The condition is exacerbated by any nose weights added for stability (which also raise the momentum of the nose) and/or a loose fit of the nose in the body. The term is named after an early '70s X-rated movie actress who, ahh, um...well, go ask your dad :-) medium power a term sometimes used to describe rockets using motors between rocket the 'D' and 'H' power classes (exclusive). Also used to sometimes describe rockets which fall between the current NFPA 1122 weight limit of 1 pound (~454 grams) and the new proposed model rocket weight limit of 1500 grams. Rockets in the 'E' through 'G' class aren't normally considered advanced, high power rockets but are often built using many of the same construction techniques as the larger rockets. model rocket An aero-vehicle that ascends into the air without the use of aerodynamic lifting surfaces. The gross launch weight, including motor(s), will not exceed 1500 grams. Motor(s) for said vehicle will not exceed 160 Newton seconds of impulse and/ or contain more than 62.5 grams of propellant each, and no more than a total of 125 grams of propellant in multiple motor situations. All components of said vehicle will be of wood, paper, rubber, breakable plastic or similar material and without substantial metal parts. Note: Current NFPA regulations (NFPA 1122) limits model rockets to ~454 grams (1 pound) gross launch weight, 115 grams total propellant, and no motor with more than 80NS of total impulse. The FAA requires a waiver application and approval for any model over 1 pound. The FAA is considering amending its FAR 101 to allow models up to the current NAR model rocket definition (1500 grams weight , 125 grams fuel...) to fly without a waiver. Model rockets in Canada are limited to 1 pound total launch weight and 80NS of total impulse. The same rules apply for construction materials as with US NFPA guidelines. modroc Model Rocket. Also seen as 'modrocer', or similar spelling, to mean 'model rocketry enthusiast'. motor Something that imparts or produces motion, such as a machine or engine. A device that converts any form of energy into mechanical energy (from _American Heritage Dictionary_). NAR National Association of Rocketry. A national hobby organization promoting model and high power rocketry in the United States. The NAR promotes rocketry related sport flying, competitions, and education. See 'Often Sought Addresses'. NARAM National Association of Rocketry Annual Meet. The NAR national championships competition, held in August of each year. NARCON National Association of Rocketry Annual Convention. An annual event sanctioned by the NAR oriented towards non-competitive (i.e., sport) model and high power rocketry. It includes seminars, R&D presentations and lots of sport flying. NARTS National Association of Rocketry Technical Services. See section 5 for address. Newton & The standard used to measure and record thrust and total Newton-second impulse, respectively, of NAR and Tripoli certified rocket (NS) motors. One pound = 4.45 newtons. NSL Nation Sport Launch. An annual, national sport fly. It has been immediately preceding each year's NARAM the last few years. NFPA National Fire Protection Association. The government body responsible for setting rules and regulations dealing with the use of non-professional rockets and motors. The current NAR Model Rocket Sporting Code was developed by the NAR and NFPA. Both the NAR and Tripoli are members of the NFPA. G. Harry Stine ('the old rocketeer') is currently the chairmen of the pyrotechnics committee of the MFPA. NFPA 1122 The current NFPA regulation concerning model rocketry. The last adopted regulations were enacted in 1987 and defined a model rocket as being less than 1 pound in launch weight, containing less than 4 ounces (~114 grams) of fuel, with no more than 160NS total impulse in all motors, and no motor over 80NS of total impulse. The NAR is currently working with the NFPA to update the definition of 'model rocket' to agree with the current NAR definition (see 'model rocket'). PMC Plastic Model Conversion. The term used to describe a plastic, static model of some type (typically an aircraft, rocket or spaceship) that has been converted to fly as a model or high power rocket. This term is also used as an abbreviation for an NAR-sanctioned competition utilizing converted models. prang Synonyms describing a failure mode whereby a model comes auger in down aerodynamically stable, in other words, 'streamlines in'. This is almost always caused by some sort of recovery system failure usually the result of a too-tight nose cone, too- tightly packed parachute or a too-loose motor that ejects out the back. Multi-stage models with upper stage ignition failures also result in a prang. The results of a prang range from no damage at all (other that a few grass stains) on lightweight sport models to the total destruction of the rocket (usually a payloader with a *very* expensive payload on board :-(. A prang that occurs while the motor is still burning (e.g. a marginally unstable rocket that becomes stable after doing half a loop due to propellant burn off shifting the CG) is called a 'Power Prang'. red baron a boost glider which has tangled with the streamer or parachute of the booster pod. The entire model tends to nose dive into the ground, like a WWI airplane which has just been shot down. R/G Rocket glider. A glider which is boosted to altitude by a rocket. The entire model glides down together. No part of the model separates, as in a boost glider. Technically, an R/G is a particular form of B/G. RMS(TM) Reloadable Motor System. The trademarked name of the Aerotech/ ISP reloadable motors. Often used (incorrectly) as a generic name for all reloadable technology. shred a model which has lost one or more fins due to take-off acceleration. Also used to refer to a shredded parachute or streamer. May also be used to refer to a model which has completely come apart during takeoff. Tripoli Tripoli Rocketry Association. A consumer rocketry organization (TRA) founded to promote the interests of high power and advanced rocketry enthusiasts. See section 5.1 for address. Tripolitan "The Tripolitan...America's High Power Rocketry Magazine". The bi-monthly journal of the Tripoli Rocketry Association, published until July/August 1992. See 'HPR Magazine'. waiver The term used to describe the official permission given by the FAA allowing rockets with more than 4 ounces of fuel or weighing more than 1 pound to be flown into FAA controlled airspace. See section 8.7 for more details. details on FAA waivers. YABAR Yet Another Born Again Rocketeer. --------------------------------------- Section 1.2: Some Commonly Sought Addresses 1.2.1 What national-level consumer rocketry organizations exist? Canadian Association of Rocketry P.O. Box 1031 Postal Station "B" Mississauga, Ontario L4Y 3W3 (416) 272-4622 National Association of Rocketry P.O. Box 177 Altoona, WI 54270 (715) 834-8074 (800) 262-4872 Email: 71331.2506@compuserve.com Tripoli Rocketry Association, Inc. P.O. Box 339 Kenner, LA 70063-0339 1.2.2 What are the addresses of the major model rocketry manufacturers? Do they offer catalogs? Note: these are just a few of the many suppliers of model rocket kits, supplies, components and motors. Refer to the list of suppliers maintained by R.M. Jungclas for a more complete set (see Section 1.3.3). Manufacturer Comments Aerotech Consumer Aerospace Large model and HPR rocket 1955 S. Palm St., Suite 15 kits, composite motors, launch Las Vegas, NV 89104 systems and supplies Email: 72020.371@compuserve.com Catalog: $2 Estes Industries, Inc. Model rocket kits & engines P.O. Box 227 (largest & most visible) 1285 H Street 1/2A through D motors. Penrose, CO 81240 (E & F motors 2nd half '92) 719-372-6565 Catalog: $1 800-525-7561 Model Rectifier Corporation A-C model rocket kits & motors 2500 Woodbridge Ave. Catalog: ?? Edison, New Jersey 08817 Quest Aerospace Education, Inc A-C model rocket kits & engines, P.O. Box 42390 launch systems, and supplies 519 West Lone Cactus Drive Catalog: free Phoenix, Arizona 85989-2390 1-800-858-7302 (602) 582-3438 (602) 582-3828 FAX 1.2.3 What are the addresses of some of the high power manufacturers? Do they offer catalogs? Note: these are just a few of the many suppliers of high power rocketry kits, supplies, components and motors. Refer to the list of suppliers maintained by R.M. Jungclas for a more complete set (see Section 1.3.3). Manufacturer Comments Aerotech, Inc Composite motors, reloadables 1955 South Palm St., Suite 15 (B - G) Las Vegas, NV 89104 High power kits, parts, supplies (702) 641-2301 or 2302 Catalog: $2 NOTE: Industrial Solid Propulsion, Inc., the parent company of Aerotech, has been the shipper of Class B reloadable motor components for Aerotech. Aerotech has recently announced that they will be the sole supplier of consumer-related rocketry kits, components, motors and reloads. All components will bear the Aerotech label. LOC/Precision High Power Kits 1042 Iroquois Catalog $2 Macedonia, Ohio 44056 (216)467-4514 Microbrick Technologies, Inc. High power kits, electronic P.O. Box 701 payloads and timers Schenectady, NY 12301 Motor distributor (518) 372-0828 Catalog: $1 North Coast Rocketry Manufacturer of HPR kits, 4848 South Highland Drive, Suite #424 parts and supplies Salt Lake City, Utah 84117 Distributor of Aerotech/ISP (800)877-6032 (voice or Fax) motors and reloads Catalog: $3 Tiffany Hobbies of Ypsilanti (THOY) HPR rocket kits, part, and P. O. Box 467 supplies. Ypsilanti, Michigan 48197 Catalog: $2 (313) 741-0847 (voice or Fax) Vulcan Systems, Inc G - K composite motors P.O. Box 6099 Catalog; ?? Colorado Springs, CO 80934 (719) 633-9889 Note: Be sure and specify that you want a manufacturer's model rocket or high power catalog. Some manufacturers offer both. 1.2.4 Are there other sources of kits, motors, parts and supplies I should know about? Refer to section 3.6 for model rocketry mail order suggestions, section 8.12 for high power mail order addresses, section 6.1 for sources of competition rockets, and all of section 5 for even more sources of information. 1.2.5. Could you please summarize published electronic mail addresses for rocketry manufacturers and individuals? Some useful email addresses follow. They are all in Internet address format. Aerotech (Bob Sanford) 72020.371@compuserve.com Apogee Components (Ed LaCroix) 71441.111@compuserve.com Estes Industries (Michael Hellmund) 71351.32@compuserve.com MRC (Fred Fischer) 70655.404@compuserve.com NAR Headquarters 71331.2506@compuserve.com NARTS, NAR Technical Services 73320.1253@compuserve.com North Coast Rocketry (Chris Pearson) 73270.2745@compuserve.com Jack Hagerty (jack@rml.com) has a much more complete list of email addresses. ---------------------------------------- Section 1.3: Other Sources of Information 1.3.1 What are some good books to read to learn more about model and high power rocketry? Handbook of Model Rocketry, Fifth Edition (out of print) G. Harry Stine Synopsis: THE handbook on model rocketry. Covers just about everything you need to get started. Good tips for experienced modelers as well. Rumor has it that a 6th edition is under preparation and looking for a publisher. It is supposed to cover HPR. Basics of Model Rocketry Douglas R. Pratt Kalmbach Books, fifth printing 1991 Synopsis: A general introduction to model rocketry. Available from NARTS for $6. Also sold at many hobby and craft stores. Advanced Model Rocketry Michael A. Banks Kalmbach Books, 1985 Synopsis: A good introduction to E/F/G level rocketry. Some good construction hints. Building Plastic Models Edited by Harold A. Edmonson Kalmbach Books, eighth printing 1991 Synopsis: Very helpful if you plan to do any PMC. Excellent sections on painting, sanding, detailing models. Good discussion of modeling tools. Famous Spaceships of Fact and Fantasy (and How to Model Them) Edited by Harold A. Edmonson Kalmbach Books, 1979 Synopsis: This book describes how several modelers built and modified some plastic models of rockets from fact and fantasy. Great hints for PMC detailing. Includes Saturn V, Enterprise (TOS), Gallactica fighters, Star Wars Fighters, shuttle Aurora from 2001: A Space Odyssey, and others. The Model Rocketry Handbook Stuart Lodge Argus Books 1990 ISBN 1-85486-047-X Synopsis: British handbook on model rocketry. Geared towards beginners, but some good tips for more experienced rocketeers. Available from NARTS for $15.25 to NAR members. Softcover, 128 pages. Scale Model Rocketry, A Guide for the Historian-Craftsman Peter Alway Synopsis: This was a limited-run, spiral-bound book that Peter published himself. Those that have a copy say it is an excellent source of scale data on a number of US rockets. It is out of production and Peter has sold out. There is no published date on a new edition. Ed LaCroix at Apogee Components had a few copies left as of May 1992. They were $19.95 plus $3 S&H. Estes Technical Reports Estes has several introductory technical reports on rocket stability, design, and other topics compiled into a publication called 'The Classic Collection'. These technical reports were first published in the 1960's. Estes also sells several other introductory books on model rocketry. NCR Technical Reports North Coast Rocketry has a very extensive set of technical reports dealing with advanced rocketry topics. These include clustering (black powder and composite engines), staging composite motors, adhesives, finishing techniques, launch systems, electronics, supersonic rocketry and 'mile high' rocketry. A number of these are available from NARTS. High power mail order shops often stock these, as well. NAR Technical Services (NARTS) P.O. Box 1482 Saugus, MA 01906 Email: 73320.1253@compuserve.com Synopsis: Ok. This is not a book. It is a GREAT source of technical, scale, and other information for NAR members. The 1992 catalog includes books, technical reports (including some of the NCR series), and a virtual plethora of goodies. 1.3.2 Are there any rocketry magazines available? "American Spacemodeling" Journal of the National Association of Rocketry Published 8 times/year; subscription: $24/year (free w/NAR membership) Subscription: American Spacemodeling c/o National Association of Rocketry Headquarters P.O. Box 177 Altoona, WI 54270 (800) 262-4872 "High Power Rocketry Magazine" An independent consumer rocketry magazine. Formerly the journal of the Tripoli Rocket Society. Published 6 times/yr; subscription $25/year (free w/Tripoli membership) Subscription: High Power Rocketry PO Box 96 Orem, Utah 84059-0096 "Liftoff Magazine" P.O. Box 9331 Grand Rapids, MI 49509-0331 Subscription: $25/year (4 issues) Synopsis: Liftoff is a ~40-page DTP-produced quarterly journal dealing with the history of space flight. It is published by Glen E. Swanson. "Model Rocket News" Estes Industries newsletter Published twice or three times a year (Fall, Winter, Spring??). Free to recent mail-order purchasers and Estes Space Club members Subscription: ???? "Estes Educator News" Estes Industries newsletter. Synopsis: A newsletter oriented to the needs of educators (teachers, rocketry classes at YMCA/summer camps, etc.). Also useful for adult super- visors in model rocketry clubs. 1.3.3 Are there any other on-line sources of rocketry related information, especially model and high power rocketry related? There are several lists of information maintained by readers of r.m.r. You can email them directly to get the latest copy of each list. These lists are also posted on a somewhat regular basis to this newsgroup. Description List of Manufacturers, suppliers, mail order houses, etc., where you can get rocketry and rocketry related engines, parts, kits, data, etc. Very extensive. Maintained by: R. Michael Jungclas Email: rjungcla@ihlpb.att.com From the introduction to the list: Below is a list of current model rocket and high power manufacturers, organizations and specialty companies. Note: Check the model r.m.r archive at SunSite.UNC.EDU for this list. List of sources for scale model data. Maintained by: Kevin W. McKiou Email: mckiou@cbnewse.cb.att.com Synopsis: A compilation of sources to get information for scale modeling projects. This list does not include any scale data in itself. It does point to places to look for scale data. Note: Check the model r.m.r archive at SunSite.UNC.EDU for this list. Model Rocketry Materials Density Table Maintained by: Jack Hagerty Email: jack@rml.com (Jack Hagerty) From the introduction to the list: The following is an informal (but hopefully fairly accurate) table of the densities of common materials used in model rocket construction. It is a running list meaning that new items will be added and existing items will be updated as I use more of them. Many of the items are commercially available, and for these I obtained values by measuring the actual purchased items, not their catalog values. Note: Check the model r.m.r archive at SunSite.UNC.EDU for this list. Model rocketry archive at SunSite.UNC.EDU Coordinated by: Robert B. Sisk (rbs@cyclops.micr.Virginia.EDU) To access the archive: The r.m.r archive is available via anonymous FTP to SunSite.UNC.EDU. Login as 'anonymous' and specify you email address as password. Rocketry files are located in one of two places: /uploads/rockets (where files are initially uploaded) /pub/archive/rec.models.rockets (the final resting place for archived files). The archive system is a Sun system running SunOS version of Unix. 1.3.4 Are there any other on-line discussion groups relevant to model and high power rocketry? There are several other newsgroups within Usenet that might be of interest to readers of r.m.r.. These include: - sci.aeronautics - sci.astro - sci.space.news - sci.space.shuttle None of the above are directly related to rocketry in any way. You can often get information on scale model sources, history of particular vehicles, etc., from the NASA and aeronautics industry people who read these newsgroups. There is a model rocketry discussion group on CompuServe. It is part of the modelnet discussion groups. Type 'go modelnet' at any '!' prompt. You must have a CompuServe account to access this list. The 'Sport Rocketry' Special Interest Group (SIG) of modelnet is analogous to the Usenet r.m.r group. Also, Internet users can mail CompuServe users if the CompuServe id is known by using the address form: 123456.1234@compuserve.com, where the correct CompuServe account number is substituted for "123456.1234" (note that a period separates the two numbers rather than a comma). If you are attempting to build or fly remote controlled B/G or R/G then rec.models.rc might have some answers for you. Finally, check with your local rocket club (NAR section, Tripoli prefect). These groups often run local BBS (bulletin boards) for the benefit of their members.