Ball differential for the OpenRC F1 car.

(Updated on 18.10.2019)

A smooth running and durable differential, which fits to the original design. The design has been tested and proven by two OpenRC F1 cars (of my kids...)

It is not fully printed - as it has many bearings inside but seems to work quite well.
Tension for the diff provided by two O-rings, and can be adjusted by the screw at the end of the shaft. The original shaft also can be used, but a longer hole should be drilled for the longer set screw. The rim at the diff has to be replaced with a front rim.

I used PETG for printing all parts (like I printed the whole F1 car).

Used bearings/O-ring:

• 1 x 51103 Thrust Bearing (18/17x30x9 mm)
  (+ using 10 pieces of 4.75mm balls from the bearing)
• 3 x 6700ZZ (10x15x4 mm)
• 2 x MR128ZZ / 678ZZ (8x12x3,5mm)
• 1 x 3x7,8x3,5mm Thrust_Bearing (e.g. F3-8M from 450Pro RC Helicopter)
• 2 x O-Ring 25x22mm (outer/inner diam)

Notes:

• The number of bearing balls on the picture is not correct, just for representation.

Updates:

2019.1018:

• STEP file uploaded
• bearings are listed
• Field experience: the diff is still working great and smooth without any issue in both F1 cars we (my kids) have.