4th axis option

Hello. I’m excited to receive my woodworker and was thinking it would be really cool if there became a 4th axis option. Realistically what are the chances of something like that becoming available?


I second this because I have experienced a fourth axis and it opens up whole new world’s.


I think I’ve seen kits, so you should be able to mod it even if it’s not officially supported.


I asked about a 4th rotary axis on Facebook and also elsewhere on this forum. Onefinity stated it was on their list of future upgrades, but made it sound like it was down on the list. The Controller is not compatible with a 4th axis as is, and an additional card/ controller will be necessary for it to work. So unless the kits that you are referring to includes the controls, we have to wait.

I believe the controller can drive one but it is based on steps so you would need to do the math based on diameter of the object for actual travel. Seems like if you were not going to do the same item a ton it wouldn’t be worth the effort as is. Seemed though like a software thing not a hardware thing. Don’t recall where I read that but I read everything I could find that they had on their site, forums and github.


This link is to the Buildbotics forum https://forum.buildbotics.com/viewtopic.php?t=138
The just of the conversation is that full rotary axis support is something they would like to add but it isn’t something that they have scheduled to work on


With the controller that is being used right now. its not likely. All 4 motor drivers are being used. Unless they can reassign one of the Y drivers. They are currently using two drivers to drive the Y axis.

Generally you could mirror and drive the Y with One driver if it will provide enough current. I guessing this controller wont provide enough and that’s why they are Slaving the 4th driver to the Y axis.


I had also inquired about this as I want to add a tangential knife in the future. When I asked BB about sharing a stepper driver, Doug responded in part:

“… you may be able to wire the two motors onto a single port thereby freeing up the fourth port for your tangential knife. Oftentimes (but not always) wiring two motors to the same port results in resonance problems between the two motors resulting in motor stalls. Unfortunately, you won’t know whether this is a problem until you try it.”


From what I’m reading, it looks like a 4th axis is not an option with the current controller board. I’m sure that these controller boards have to be bought in bulk, so changes it the near future is not likely. For me, this weighs heavily on my choice to buy this machine. I have heard of using the x axis to drive the “4th” axis. Does anyone have experience with this?

While xzb (continueis) 4 axis cutting looks to be out with this controller, xyz+ manual b looks totally doable.
I don’t know your use case but something to consider.

1 Like

I just set up mine to run a rotary as the Y-axis and it works fine. I’m sure you could run it as the X-axis as well. I’m using vcarve and only using it for the laser so far. So I just modified the post processor for the laser by adding in a wrap Y to A and then went into the controller and changed the M1 from Y to A and inputted new settings for the rotary axis. It works for me being able to laser engraved on tumblers so far.


Here’s a picture of mine at the moment. Just clamped to the table at the moment. Waiting on some aluminum plate to make a spacer to be able to bolt it to the table at a better height and have a set place to put it everytime, and be able to move the rotary after im done with it leaving the spacer behind. I do wish the controller had the ability to keep all axis available and use a 4th axis but at the moment it’s not able to, but maybe in the future it can. This is just an easy way I found to be able to use a rotary to laser some round things.


Can you provide links and details on the parts you used?

I used one of these because I needed a big enough chuck to hold a big tumbler. But I’m sure most rotaries will work. This one also has a Nema23 stepper with four wire output so it was an easy wire up to our controller. Colors of the wires were not the same as the stock cable we get from Onefinity but as long as you hook up A+ to A+ and so on it’ll work fine. https://www.amazon.com/dp/B07B2RX1BK/ref=cm_sw_r_cp_apa_fabc_6D1KTQSA81MN2J15JHP7?_encoding=UTF8&psc=1

This is all I am using besides the stock onefinity. I need to do some measurements and make sure I have the exact numbers I need for my movements but it’s pretty close if not right at the moment. I’m using Vcarve desktop and modified the laser post processor to add in the wrap command.

1 Like

Thank you for sharing the information and link. I was planning on adding a rotary axis in the future as well but also for carving. I have seen that others using a belt driven chuck commenting that there is negligible run out, have you noticed this as well?

I have only used mine for the laser so far and it’s been working great for that. Not sure on the runout really yet I’m sure it’s pretty small and not noticeable for me.

There were a lot of good upgrades/ accessories announced over the last couple weeks, but I am dis-appointed that a rotary 4th axis solution was not one of them. Sure hope that we won’t have to wait until next year @OnefinityCNC.


This would be awesome!
I vote for 4th axis.


My understanding is that the controller can’t handle a true 4th axis but rather a replacement of x or y with a rotary. There are some discussions on the buildbotics forums about this and the complexity of steps vs diameter of object


Yes this is true. Unless there is a new controller or some kind of expansion board or something. Right now you just have to replace the x or y axis with the A axis. I have done it. It isn’t hard and worked fine for what I wanted to do. I have one of those posts on the buildbotics forum lol.