DeskProto user forum

I'm trying to machine a small section of a "barley twist" furniture leg as a prototype, but I am seeing unexpected results in the end product. It might be a bit difficult to see in the photo, but the overall diameter of the finished twist is much smaller than the model while the number of twists is higher than the model. I have machined this part twice with the same results. I've triple checked my zeros, tool properties, part scaling, and everything else I can think of.

Any ideas out there for me?

If the number number of twists ist higher then please check if a 360 degrees ration is really done like expected. It seems that the number of steps set for a full rotiation is different from then the number needed.

I agree with Hirnholz about a possible cause for the different number of twists.
For the total dimensions you can check if a movement of 100 mm along X (shown on the display of your control software) is indeed 100 mm on the machine.
The different shape of the ridges can be a cutter error: this would be the result when you calculate toolpaths for a ballnose cutter and machine with a flat cutter.

Thanks HirnHolz and Lex. The actual rotation for an expected 360 degree rotation was actually 720 degrees. I've been using it that way without knowing it for several months, but this was the first non-symmetrical part I've tried to machine on the rotary axis. Thanks again!