Fun summer project for me and my son.
-it uses super cheap (under 10eur) A2212 1000K brushless motor + ESC set from China (BangGood, Gearbest, DX...). Speed cca. 30km/h on 2S LiIon
-any 2chn remote will do
-9g servo for steering. 2 mounting screws come with servos. Connected with 1.5mm music wire with steering mechanism
-most parts are 3d printed in grey ABS. All parts can be printed without supports on any FDM printer, if oriented correctly
-bottom is cut from 1.6mm FR4 PCB material. Can be 3d printed, if your printer can print 210mm part. I would print it at least 3 mm thick (scale model before slicing in Z direction) There are STL nad DXF files for bottom.
-shaft and axes are from 6mm round aluminium rod (I had that available on hand). Can be any round metal in rod or tube form with 6mm outside dia.
-all bolts (26pcs?) are M3x10mm phillips cheese-head. Nuts are standard M3. Use washers under nuts if you wish
-king pins for front steering are from 4mm round material. I used brass tube, but again, material is not critical. Use what you can find
-2pcs of 626ZZ and one 624ZZ bearing
-have some washers for 6mm screws on hand, as distancers for weels
-tires can be printed from flex filament or casted from 2-part silicone in 3d-printed molds. I casted them, soft silicone has much better grip on any surface. Files for 3-part molds are included
Both gears are press-fit mounted, small one directly on motor shaft and large one on 6mm rear-shaft. Rear wheels are also just pressed on shaft (if hole in wheels is pre-drilled with 6mm drill, then they will press-fit perfectly onto 6mm rod). Use some 6mm washers on axe as distancers between rear wheels and bearings. Front wheels are drilled with 6.2mm drill and they turn on axe freely, they are secured with press-fitted caps. Some 6mm washers will be needed here as well.
Fusion 360 and STEP files available on Grabcad:
RepRap Huxley Pro (oh yeah...)
can be printed in other materials, PLA should be fine also.