Quote Originally Posted by Kered View Post
If the 4th axis is for marking round parts like a rolling pin etc. I have done it on my laser engraver by using a small stepper and connect it to the Y axis, intead of the gantry moving the length it stays still but the rolling pin turns as the laser writes, not sure which axis is which on a cnc router so it might be X in your case. Its a simple device with a 3d printed mandril one end that grips and a pinpoint on the other and the work is held in between, I'd upload a photo but i gave it to a friend. Its not a full permanent 4th axis but you can write on round tubular objects, on a router probably cut them too. Not sure if its what you need, just a thought.

Derek
PD Are you the same Andyuk that designed the belt tensioner for the eleksmaker A3 pro laser engraver, every time I see a post of yours it reminds me of it as the way you write AndyUK is the same.
Hi Derek,

Sorry, not the same, just another Andy from the UK ;)

Yes I've seen that type of 4th axis, quite ingenious! I worry about the accuracy of such a system though, and I wonder if the Cam is a nightmare! I was more thinking along the lines of a high torque stepper, some gear reduction, a chuck and a tailstock.

Thanks for that Jazz - much appreciated.