I have an old ender 3 that I have been using for small laser projects and recently need to add a rotary axis. Marlin does't seem to want to run a rotary axis with out having to do a bunch of firmware changes (and even then it doesn't play well.) I purchased a black box earlier this year for a build I haven't started yet. So my question is to set up the 4th axis as A axis do I just leave the slave jumpers off? All I can find in the documentation is how to set the forth axis as a slave to X, Y or Z, is it possible to run it as a true forth axis (a)? I think I may just run the black box to run my ender 3 hardware with a rotary axis util I get around to building my other frame. Any insight on this would be awesome!
Correct. BlackBox's 4th (Y2) driver is just a slave jumpered to X Y or Z. See docs.openbuilds.com > Slave axis Jumper
Grbl itself does not support rotary axes, but Vectric can wrap artwork around an X or Y pseudo axis: See Rotary Machining and Wrapping - VCarve Pro V9.0 User Manual which is what most folks use with the BlackBox to do rotary work You can buy Vectric from Vectric Products - OpenBuilds Part Store
As above have said GRBL is limited to 3 axis. If you want to control more than 3 axis the Duet controller which is used in 3D Printing and CNC'ing can control more than 3 axis and is fairly simple to setup: Gcode
Ok, new to building a CNC, been using them for many years. Let's see if I have this right. 3 Axis is a limitation of the Control software, not the BlackBox? if so is there control software to use with the Blackbox that will allow 4 Axis operations?
No, Grbl is limited to 3 Axes (BlackBox runs Grbl Firmware - see github.com/gnea/grbl). However, as noted before, that's not a big limitation. In a typical CNC you are either busy doing 2.5/3D work (Plug Y axis motor into Y port) or doing Rotary (Lock gantry above the rotary axis, then plug the rotary's motor into the Y motor port. Then just use Gcode Wrapping to run the Rotary as a Y axis. Simple, cheap, easy
Hi Peter, I have read a lot of responses concerning a rotary 4th axis with GRBL on the Blackbox. I currently have the Blackbox and use V-Carve pro as my CAD program. V-Carve can design a rotary item but will it run on the Blackbox on the Y2 Axis?
