Truck v3 belt gearbox

Last crawled date: 4 years, 3 months ago

WARNING: I tested the transmission today, and it turns out belts need to be tighter, they are skipping. I will try with 110 tooth belt first, as I want to avoid additional tensioners if possible.
I investigated and figured one of the belts was skipping as I had a bad print which caused the centers of the two 8mm shafts to come closer. I replaced the original 112 tooth belt with 110 tooth belt and the issue is gone. I left the motor belt at 112 tooth.
Be aware that too tight belts will cause the motor to draw very high currents, in my cse it was in the high 22A if I switched both belts to 110 tooth versions. Keeping the motor belt at 112 tooth and the output belt to 110 tooth solved the issue for me. So in essence this is a design with no tensioners, so order both 110 and 112 tooth belts and experiment whith what works for you. Be sure to measure the operating motor current, otherwise you risk frying the motor.
Good news is that the transmission is a lot quieter.
This is not a project for the faint of heart.
It is a nightmare to print, and a nightmare to assemble.
Yet it provides quieter operation than the geared gearbox.
The gearbox is approx. 1 cm longer then the original design, so if you have a bed on your truck, you will need to modify it.
Hardware:
2x 110 tooth 2GT belt
2x 112 tooth 2GT belt
2x 20 tooth 2GT pulley with 8mm bore, 6mm width
2x 40 tooth 2GT pulley with 8mm bore, 6mm width
2x 8mm metal shaft
4x 6700 bearings
EDIT: added *.stl for shafts for reference, added a square interface output shaft that can use u-joints from MrCrankyface original design. But if possible just file down some metal shafts, as I am not sure how durable plastic ones are.