Des, My original design uses a "break switch" type system. A few people asked me about designing one that uses a "G SWITCH", like a high number of the ones available from Public Missles, BlackSky, ... etc. The timer that I sell costs less then US$30.00, a G-SWITCH doesn't seem worth it to me. Thanks. Steve www.xavien.com Des Bromilow wrote: Steve, I make my own. very easy, and quite reliable, very repeatable, etc. Do a search on the adept website for their timers, and check out the mechanical system they use (a swinging arm, and a microswitch.) I also use another system (even smaller and cheaper) which is a little harder to make. It's based on a spring from a pen, a small sleeve of plastic, and a tinned wire. I can explain it if you need, but for beginnigs I'd suggest the Adept system. Second question.. do you really NEED a G-Switch? The simplest sytems use break wires, pull pins, etc. These systems sometimes are the ONLY system that works (particulalry for long burn, slow engines) If you need commercially made G-Switches, get yourself to a supplier like Jim Ball, or some of the other amatuer suppliers.. be warned, a MIL-SPEC switch will set you back around $30+ USD. HTH, Des Bromilow Queensland Rocketry Assoc. >>> steve_piclist@YAHOO.COM 9/07/03 5:22:49 am >>> Friends, I am trying to find a company that sells "G-SWITCHES" that are used in model rocket timers. Do companies make these, I keep seeing references to them on rocketry related sites, but doing a search with GOOGLE turns up no suppliers of these things. I can't even find an explanation as to what they do exactly. Any help much appreciated. Thanks. Steve --------------------------------- Do you Yahoo!? The New Yahoo! Search - Faster. Easier. Bingo. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details. ________________________________________________________________________ This email has been scanned for viruses by the CITEC Email Anti-Virus service powered by MessageLabs. For more information on a proactive email anti-virus service working around the clock, around the globe, visit www.citec.com.au ________________________________________________________________________ ________________________________________________________________________ This email has been scanned for viruses by the CITEC Email Anti-Virus service powered by MessageLabs. For more information on a proactive email anti-virus service working around the clock, around the globe, visit www.citec.com.au ________________________________________________________________________ -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details. --------------------------------- Do you Yahoo!? The New Yahoo! Search - Faster. Easier. Bingo. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.