Robin, actually I cheated....:o

I drew a 100mm radius circle in AutoCad and then drew a square inside it. Measured the side length of the square and saw it was 141.4mm...an old familar number related to the sq.root of 2. Then it all fell into place.....:)

I did always know that the area of a circle inside a square is about 3/4 of the square area, but that it is exactly 3.14/4 (pi/4), so I did have a suspicion there is a linear relationship to pi for square inside the circle.

Every one else has been designing reduction drives I thought I would have ago.
Mine will be made from cast aluminum and fully enclosed so that I can take advantage of plastic pulleys.
Also I have done away with the laser cut bracket and mounted it to a custom long stud with a large flange to elimiate twisting.
Pictures are of a MDF prototype, the design has slightly changed, they give the general idea.
The image of the reduction on the machine shows it on the wrong side - the reduction housings are universal.

Now, that is the right way to do a belt reduction box :D

It also look like your design can be machine off a block of aluminum :)

i like the reduction design. It will be casted very well in Aluminum. Thanks for sharing.

Hi Anthony

Must be that time of the year for designing belt reductions :).

I like your design, especially the symmetry that makes them universal.
After a few quick calculations I see that 2 x 12 mm plates are never going to make a fully enclosed drive.
Is that why you have chosen casting due to the depth of the assembly?

As an aside if my limited experiences so far with the 4:1 reductions are any thing to go by, you will enjoy having them on your machine.
Just pushing the gantry up the machine when the motors are off is telling me so much more is going on!!

Regards
Ross

Wow! that looks fantastic, I like the closed design.

Ross,
I wanted enclosed for dust and swarf.
It had to be light weight for plasma cutter to help acceleration and using a plastic large pulley will help with weight but also rotating inertia.
My aim is to go from 16 mirosteps to 4 mirosteps = more torque + 5.2:1 reduction = more torque. I then maybe able to lower the amperage without sarificing performance(??).

Anthony