PIC Users, In response to several questions about Muscle Wires I have forwarded a copy of the latest FAQ file from Mondotronics, the company that makes them. Roger Gilbertson, the president, makes his e-mail address available for other questions. It is in the FAQ. Have fun, Martin Kirk Arizona State University mlk@asu.edu (602) 263-9270 ---------- Forwarded message ---------- Date: Tue, 29 Nov 1994 19:38:11 -0800 From: Roger G. Gilbertson To: mlk@asu.edu Subject: Muscle Wires(R) FAQ Hello Martin - Thank you for your interest in our Muscle Wires(R) products. Here's our latest Muscle Wires Frequently Asked Questions file. We also have a product flyer as a separate email file. Please request it from us if you have not received it already. If you provide us with your postal address we will send you our printed version (with photos) and keep you informed with future mailings. Thanks again for your interest! Roger G. Gilbertson President /\ /\ /\ //\\//\\//\\ Mondo-tronics, Inc. Phone 415-455-9330 ///// // // ///// 524 San Anselmo Ave #107-20 Fax 415-455-9333 \\//\\//\\// San Anselmo, CA 94960 email info@mondo.com \/ \/ \/ USA Order Line 800-374-5764 ====================================================================== MUSCLE WIRES - FREQUENTLY ASKED QUESTIONS email V10 Q: What are Muscle Wires? A: Muscle Wires are thin, highly processed strands of a nickel-titanium alloy called nitinol - a type of Shape Memory Alloy that can assume radically different forms or "phases" at distinct temperatures. Q: How do Muscle Wires work? A: At room temperature Muscle Wires are easily stretched by a small force. However, when conducting an electric current, the wire heats and changes to a much harder form that returns to the "unstretched" shape - the wire shortens in length with a usable amount of force. Q: How much do Muscle Wires shorten? A: Muscle Wires can be stretched by up to eight percent of their length and will recover fully, but only for a few cycles. However when used in the three to five percent range, Muscle Wires can run for millions of cycles with very consistent and reliable performance. Q: How strong are Muscle Wires? A: Large wires are stronger than small ones, and strength varies with diameter. The strength to expect from a wire when heated is shown by the Recovery Weight in the table below. The Deformation Weight indicates the amount needed to stretch a wire when cool - about one sixth the force exerted when the wire is heated. Our largest wire has over 45 times the strength of the smallest size, so you can easily match wire strength to your needs. Q: What if I need more strength? A: For more strength, use two or more wires in parallel. This gives you as much strength as needed, and still keeps the fast cycle times of smaller wires. Q: How fast can Muscle Wires activate? A: Muscle Wires contract as fast as they are heated - in one thousandth of a second or less. To relax, the wire must be cooled, which depends on the conditions surrounding the wire, and its size. Our new Flexinol HT series of wires has a higher transition temperature and cools up to 50% faster than the LT wires. The table below gives typical cycle rates for both LT and HT wires in still air. Moving air or immersing the wires in a fluid like a water/glycerine mixture can increase these by ten times or more. Q: How much power do Muscle Wires use? A: The power needed to activate a wire depends on its diameter, length, and the surrounding conditions. The table below gives typical current levels for "room temperature" conditions. Power can be increased, but once the wire has fully shortened, power should be reduced to prevent overheating. ----------------------------------------------------------------- Table 1. Flexinol Muscle Wire Properties ----------------------------------------------------------------- Wire Linear Typical Deform. Recovery Typical Wire Diameter Resist. Current Weight* Weight* Rate** Name (microns) (ohm/m) (mA) (grams) (grams) (LT/HT) ----------------------------------------------------------------- Flexinol 037 37 860 30 4 20 52/68 Flexinol 050 50 510 50 8 35 46/67 Flexinol 100 100 150 180 28 150 33/50 Flexinol 150 150 50 400 62 330 20/30 Flexinol 250 250 20 1,000 172 930 9/13 ----------------------------------------------------------------- * Multiply by 0.0098 to get force in Newtons ** Cycles per minute, in still air, at 20 Centigrade LT = low temp 70 degrees C, HT high temp 90 degrees C ----------------------------------------------------------------- Q: How long do Muscle Wires last? A: When used in the three to five percent range under proper conditions Muscle Wires can run for millions of cycles. Often, other parts of a device will fail or need adjusting long before the Muscle Wire does. Q: What are the advantages of Muscle Wires? A: Compared to motors or solenoids, Muscle Wires have many advantages: small size, light weight, low power, a very high strength-to-weight ratio, precise control, AC or DC activation, low magnetism, long life, and direct linear action. These features let you create whole categories of amazing new devices that would be difficult or impossible with anything other than Muscle Wires. Q: What are the keys to using Muscle Wires? A: For longest lifetimes and best performance from your Muscle Wire devices, follow these key points: * Have good electrical & mechanical connections. * Protect the wire from overheating. * Protect the wire from overstraining. Each of these can be accomplished in many different ways. These topics and more are covered in detail our new 128 page "Muscle Wires Project Book". For more on this book and all our other products, see our Muscle Wires Products flyer. Please request it if you have not received it already, and contact us with any further questions you may have. Thanks again! /\ /\ /\ //\\//\\//\\ Mondo-tronics, Inc. Phone 415-455-9330 ///// // // ///// 524 San Anselmo Ave #107-20 Fax 415-455-9333 \\//\\//\\// San Anselmo, CA 94960 email info@mondo.com \/ \/ \/ USA Order Line 800-374-5764 ====================================================================== Legal. (C)1994 Mondo-tronics, Inc. Muscle Wires is a registered trademark of Mondo-tronics, Inc. so please use it with the M and the W capitalized. Eat your vegetables. :(*) E-FAQ V10.1 9411.01