Rotary axis question

[ShaneBell]

Say if one were to purchase a rotary axis and it had the same spec nema 23 as the machine already has and is direct drive would the steps per mm have to be changed. And yes I already know 3 axis machine and all the other good stuff just wondering if the steps per mm stay the same as the say the x,y axis. And if a change has to be made how would I know what the setting would be?

[ErikJenkins]

Check out my thread on the rotary axis

It's Alive

Here is one problem with using a rotary axis with grbl…each time a different size cylinder of wood is cut, the steps per mm must be adjusted to match that particular piece of wood, not a huge problem, but just adds a bit of time to a project. Once I get the new electronics installed, it won’t be an issue as true rotary axis support moves the axis by degrees and not linear movement. Not a show stopper, just something to consider if anyone plans on going this route and staying with grbl.

[ErikJenkins]

Another comment on that very thing…a few posts before the one above.

It's Alive

For the steps per mm, It was a little trial and error and a little math :-). The diameter of the dowel was 1.125 inches I multiplied that by 3.14159 (pi) to get the circumference of the dowel, 3.534 inches. I made a mark at the bit location, told the machine to move 3.534 inches to rotate the radial axis, if correct the axis should rotate 1 full turn and stop on the mark. I adjusted from there. When I replace the electronics, once everything arrives, the calculations will be translated to de…

[LarryM]

Just a note. Vcarve PRO has built-in support for a rotary axis. It works on a three axis controller. The rotary axis substitutes for either X or Y, designers choice. I haven’t worked with this yet.

I think it requires a different post processor. They have a folder of PP named 05-Wrapped. A post processor may have to be developed for the X-carve.

[ErikJenkins]

The V-Carve post processor for the rotary axis works great, I do not use one for GRBL, I use the Mach3 one. Before I switched to Mach3 I used CNC Wrapper to convert my Y axis movement to A Axis rotary movement.

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