Sounds like a cross bow to me... John Ferrell 6241 Phillippi Rd Julian NC 27283 Phone: (336)685-9606 johnferrell@earthlink.net http://DixieNC.US NSRCA 479 AMA 4190 W8CCW "My Competition is Not My Enemy" ----- Original Message ----- From: "Tal" To: Sent: Thursday, January 08, 2004 7:34 PM Subject: Re: [EE]: Sled propulsion > A firework maybe? > > Tal > > -----Original Message----- > From: pic microcontroller discussion list [mailto:PICLIST@MITVMA.MIT.EDU]On > Behalf Of Jinx > Sent: Friday, January 09, 2004 2:30 AM > To: PICLIST@MITVMA.MIT.EDU > Subject: [EE]: Sled propulsion > > > Does anyone have suggestions (and hopefully practical > experience) for methods of propelling a sled on a track ? > > Sled weighs about 500g, hopefully much less but it will be > > 200g. Length of travel can be anything up to 2m. Shorter > is better but not important. It's required that the sled reach > full speed by the end of the track (obviously !). This speed > needs to be accurately set from 10m/s to 45m/s > > My thoughts - > > Air (how would speed be regulated ? Bleeder valve ?) > Electromagnetism (ie rail gun - ambitious ?) > > Things like shotgun cartidges are out. Driving force has to be > something reasonably non-consumable (eg air, electricity) and > that can be reset fairly quickly and repeatably, say within 20s > > Water would be too messy > > I don't know if motorisation in some form would work. For example > direct drive with a stepper or clutching a flywheel > > At the end of the track I thought the sled could be sent down a > downward curve, deccelerated with electromagnets or track > braking and then travel upside-down in a loop to get back to the > start position > > TIA > > ============================================== > Research is what I'm doing when I don't know what I'm doing > - Wernher von Braun > > -- > http://www.piclist.com hint: The list server can filter out subtopics > (like ads or off topics) for you. See http://www.piclist.com/#topics > > -- > http://www.piclist.com hint: The list server can filter out subtopics > (like ads or off topics) for you. See http://www.piclist.com/#topics > -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.