Quote Originally Posted by Fozz84 View Post
I havn't bought anything the reason i asked was that 8mm seemed a bit small for a large machine. i can twist steel with a impact wrench of that thickness.

ok so it looks like its back to making the rack and pinion design.

need to find a engineering company locally to cut the side plates and swing arms. (once i have the design finalised)

hopefully you can make out the idea for the pressure adjust on the rack and pinion. it is early stages but closer than most.

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the more i look into it, the more complex it is. not impossible though
You will need to size the motor correctly for this setup because you will have a lot of friction with that system. Also pay attention to the number of teeth engaged in the motor pulley, how you have it drawn there you won't have enough teeth engaged. This will lead to greater torque per tooth and potential tooth jumping and excessive belt wear.

If you want anything like decent power and speed then you'll need Mains powered stepper system, 70-80Vdc drives won't cut the mustard with this setup and size of machine. But if you do go with low voltage drives then make sure the motors have the lowest inductance you can find.