So this weekended I have been working on finishing the design of the drive system. I have updated the initial design of the 2-pulley gearing into a 4-pulley gearing. The main reason for the update is to have the ability the to achieve a lower wheel surface speed. The brackets are also designed with adjustable offsets, so each component can be adjusted to tighten the belt, or allowing a easy change off pulley sizes without redoing brackets.
In the gearing in the picture above will reduce 1000RPM to a theoretical 41RPM and 0.5m/s wheel surface speed with Pulleys sizes P1=55mm, P2=100mm, P3=15mm and P4=15mm. My current plan is to use 80mm Diameter pulleys for P1 and P2 therefore I only need to print 4 pulleys with the same design and size.
The gearing will then be the following:
P4/P3 = 80/15=5,33 ratio P1/P2 = 80/15=5,33 ratio
The transition between each pulley with 1000RPM at P4 will translate in to:
P4/P3 = 1000/5,33=187,61 RPM P1/P2 = 187,61/5,33=35,2 RPM
My goal is a 0.4m/s wheel surface speed. Would give me 0.4*60/0.7225=33 RPM on the wheel shaft. So I am within the limits to achieve that.
So this is the final design of the drive system.
Next week the CNC milling of the motor brackets will begin!