Torsen Type 2 Differential for Tarmo 5

Description

This is a differential.  The mechanical part allows the left and right tires to rotate at different speeds which improves handling when cornering.  The Torssen Type 2 was chosen because the differential is intended for a off-road RC car so the differential ensure both wheels retain traction even on mud, snow or when one wheel is in the air. 

Differential video: 

Non printable parts.

3 mm rod:

https://www.amazon.com/dp/B0DCBCRB1C?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1

3x8x3.5 mm trust bearing. one 

https://www.amazon.com/dp/B082PSL3SG?ref_=ppx_hzod_title_dt_b_fed_asin_title_0_0&th=1

3 40m  m3 screw

1 18mm m3 screw

3 m3 lug nut

https://www.amazon.com/dp/B0D146SHYF?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1

Printing:

The Gears:

The inner and outer gears were printed with 2.5 mm nozzle. Because the gears are so small, the more resolution the better.  But you may get away with 0.4mm nozzle.  Let me know if you try it. 

Print with 10 perimeters to make sure the parts are all plastic since they will experience a lot of torque and shear. 

The Case

The case should be printed with 0.4mm nozzle.  Use concentric infill 

perimeters: 8

infill  20%

Use Concentric infill to make sure the part is balanced. 

If you are going to use it on a Tarmo 5, print the 50 teeth gear.

If you are going to use it on my remix called Moster Tarmo, use the 44 teeth gear.

Assembly

WARNING:  Notice the parts are mirror image of each other.  Don't print one twice thinking it will work. 

print 3 of each of the outer gears  ( 3 clockwise and 3 counter clockwise ) 

print the two inner gears. 

Cut the 3mm rods into 6 40mm rods ( or purchase them precut ).  

Print the new C02 part twice.  

 Notice that the inner gears and the outer gears twist clockwise and counter clock wise.  Place them in the gear case and play around with them.  There is a wrong way and a right way.  If you do it the wrong way the gears will not fit.  All the outer gears that twist in the same direction go into one side of the case.  and the other three go in the other way around. 

Make sure to insert the M3 18mm screw going through the two inner gears.  This will prevent the trust bearing from getting out of position as the car turns. 

The case should just fit into place.  If not, check the rode length is at or slightly below 40mm.  Use a file if needed.  DO NOT try to use the screw and lug nut to reduce the gap to close the case.

TIP:  Use the C02 parts to rotate the gears.  This will help you get the rods to fall into place so you can close the case.