4th axis option

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.

T

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.”

Tom

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.

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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.

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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.

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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.

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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.

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

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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

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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.

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Replacing the x or y axis will allow you to use a 4th axis rotary, as long as you don’t need to control the radius. I would like to use the 1F to 3D carve table legs and other items that would require the controller or some sort of add on card to do the step vs diameter calculation as BJ suggested. When I originally bought my unit, it was mentioned as something they were working on, but Onefinity hasn’t commented since.

Roger would it work instead of using the m1 for a axis to use the m0 the x axis as the A? just thinking

Yeah as long as you change everything to the X axis instead of Y

Mr. Roger,
Here we go sir,
I change the settings per instructed in rotary setup for onefinity,
Rotary attachment responds to nothing when the axis is changed to A, but when I change the travel-per-rev and the step-angle but don’t change the axis to A, but leave it at Y now it responds, 360mm turns 1 complete rotation

I am wondering if the updated firmware changed the a possibilities or if there is something I am missing,

Please advise sir,

How are you checking for movement of the rotary when it’s the A axis? You can either enter gcode saying to move the a axis or you can use the joystick but you can’t move it with the arrow keys on the home screen of the controller if you are trying that way. @GregoryG

I’ve not tried gcode but I’ve tried the joy stick
Tomorrow I’ll record it so you can take a look I’d you will