Cart Pulling Robot

thingiverse

Here is another walking toy design that pulls a cart. This one uses a similar construction as a previous design I did. You can see it at https://www.thingiverse.com/thing:4020131. This toy has a kind of steam punk look with a wooden cart and boiler. The pivots are made from T-pins, which I bought at Walmart. They have a 1 mm diameter. The motor is a commonly available 6V 100 rpm N20 gearmotor powered by a 150 mah lipo battery. The battery was purchased from Banggood and came with a charger and small jumper cables. You need to use one of the charging cables to hook the battery to the motor through the switch. The switch is from a tea light. The battery is just stuffed in the boiler, and you can access the connector for the battery to recharge it by removing the back of the boiler, which is held on by a screw. Here are the parts needed: * 6V 100 rpm N20 gearmotor * 1/8 inch or 3mm dia X 32 mm long rod. I used 1/8 inch brass brazing rod. * 2mm X 8mm self tapping screw * 150 mah lipo and connector (https://www.banggood.com/5PCS-Eachine-E010-3_7V-150mAh-Battery-RC-Quadcopter-Spares-Parts-p-1081736.html?rmmds=myorder&cur_warehouse=CN) * Switch from a tea light * 1mm diameter T-pins * Heat shrink tubing * Super glue and hot glue Here are the build notes: Make sure to remove all burrs, bumps, and anything else that might interfere with free movement. I use a small rat tailed file for inside holes and gear teeth, but a hobby knife would work. A sheet of 200 grit sandpaper on a flat surface works for flat parts. A nail file board also works well. There are several 3d printed threaded parts. The internal threads should be cleaned out with a 6mm X 1mm tap. If you don't have a tap, you may be able to use a 6mm bolt with a groove dremeled into it. I haven't had to use a die to clean up the external threads. Run a tap through the threaded holes in the frame and cart. It's best to first wire the motor to the battery and then assemble the rest of the toy. The T-pins used for the pivots are held by friction to the parts upper_legs and foot. The mating holes are designed with more clearance so the pins pivot freely. After inserting the pins through the parts, they are cut off flush with side cutters. The 3 parts of the head are super glued together and then to the main body. Here's a video of the toy with some details: https://youtu.be/JD8gFildHE0. If I missed a file or some other detail, let me know and I'll try to fix it. Good luck!