Help about Pulleys and belt for 4th axis

[Rene Nuñez Paz]

Hello,

Iam building my new cnc machine, In this moment i have a JGRO Type cnc machine, powered with 4 axis Hobby CNCPRO controller card and 305 oz/in unipolar stepper motors.
I want to build a 4th axis, My idea is use the reduction with timing belt, and two pulleys.

My stepper had ¼” shaft, I think to conect a little pulley of about ¾” external diameter and ¼ bore
.
The big pulley I think that can be a 3” or 4” inches diameter. For the bore I don’ have Idea.

Distance betwen pulleys aproximately 8-9 inches.

I don’t have idea about number of teeht in pulleys, timing belts, etc.

May somebody help me? Please sugesting me kind of pulleys and timing belt and in your opinion best suppliers?

Thanks in advance

Rene

PD-Excuseme my bad english , i hope you understand.

[dgoddard]

Take alook at the sdp-si site. Will answer all your questions on pulleys, belts, etc. For my 4th axis I am using two XL pullies (a 72 and 17 tooth) for the reduction. On my setup the spindle dia is 28mm, think largest hole dia is 0.5", so bored hub to fit. I use a 3/8" width XL belt and it works fine. Good luck.

http://www.sdp-si.com

[Rene Nuñez Paz]

Thanks

I'll check the link.

May I take a look to your 4th axis?

Thanks again

Rene