Micro RC Snowcat - 1/35th Scale Bombardier BR400

thingiverse

This is a micro snowcat I've designed that runs on two N20 gearmotors, a couple cheap brushed ESCs and a 2s 500mAh lipo. It's loosely based on the Bombardier BR400 with some artistic license taken to make printing with FDM easier in this scale. I also added a simple bogey-type suspension supported by mechanical pencil springs to help it traverse rough terrain a bit better. This is more of a "scale model" that requires some patience to assemble especially considering the track links are individual and many of the parts are quite small. Utilizing worm-gears for the main drive gives this model a lot of torque and a very scale speed (i.e. slow), coupled with the 500mAh lipo puts out run times near 15-20 minutes. Size is about 125mm long x 130mm wide (track width) x 80mm high (to top of body). Here's the BOM, parts with links are where I sourced mine, the other parts I found locally but could easily be found on Ebay or Amazon. Parts List: - 6v 600RPM N20 Gearmotors w/3x10mm shaft (x2) https://www.ebay.com/itm/N20-30-600-1000-1200RPM-DC-3V-6V-12V-Micro-Deceleration-Gear-Reducer-Motors/153288110648?ssPageName=STRK%3AMEBIDX%3AIT&var=453168778441&_trksid=p2057872.m2749.l2649 - 10A 2s Compatible Brushed ESCs (x2) https://www.amazon.com/Hobbypower-Brushed-Motor-Speed-Controller/dp/B00JXI3H6Y/ref=sr_1_1_sspa?keywords=10a+esc+hobbypower&qid=1560481016&s=gateway&sr=8-1-spons&psc=1 - 0.5 Mod 1:10 Worm Shaft and 20 tooth Worm Gear (x2 sets) (Of all the parts these are the hardest to come by, this is the cheapest I could find them) https://www.ebay.com/itm/192706558865 - 4x4x11mm Ball Bearings (x4) - 4mm (5/32") Brass Rod (x2 40mm long pieces) - 4mm (5/32") Bore Copper or Brass Shim Washers (x2-4 depending on thickness and tolerances of parts) (These aren't completely necessary but helps to reduce endplay on the driveshafts and properly align the worm gears) - 8x2mm Disk Neodymium Magnets (x4) - 5/32" ID Shaft Collars (x2) (OD is 5/16") https://www.ebay.com/itm/Great-Planes-Plated-Wheel-Collar-5-32-12-GPMQ4307/113677646566?epid=15012062036&hash=item1a77b73ae6:g:WlMAAOSwI7JcgZgZ - M1.7x8mm Screws (x18) - M1.5x5mm Screws (x3) - Satin Sewing Pins (Size 17, should have a .7mm dia. shaft) Trim to 24mm and 16mm lengths (x86 of each length) - Mechanical Pencil Springs (x4) (Ball-point pen springs might work but are much bigger in diameter and may interfere with the suspension arms and/or tracks) - Micro Receiver (x1) (I used an AR6100e for my Spektrum Transmitter) - 500-550mAh 2s Lipo Battery (x1)