Illusive Chuck Rotary Set Up

I have a Chuck Rotary from OMTech. Red and Black 60W OMTech Laser. I have read many posts and saw one that was very similar to my issue. I went as far as counting the teeth on the motor to find the ratio.48 and 26, 9230 Steps per rotation.

I have checked the stepper motor for the Y axis, It is 5000. I have the DM545A. My manual says the Pulse/Rev default is 4000. I replaced the original controller and have the Ruida RDC6445G. The dip switches on my motor indicate 5000, 2, 4 and 7 are ON.

I do the TEST in the rotary set up and it rotates 2.25 times. I can get to rotate just once by changing the diameter - which should NOT be a factor. If I send a job, the rotary does not move.

I have done set up: send file to Laser (use current position), align the X where you want it and manually the Y, Press “Origin”, then play. The numbers for the Y axis on the controller show it moving the distance of the line I have sent to engrave; BUT, it does not move at all. See videos.

Link to my rotary.

Threads I read - similar issue. Post1



And many others. So very frustrated. Help!

Some Pictures:

More Pictures:

Sorry, having issues with the videos.

There doesn’t seem to be any artwork on your machine console? What is the art you are trying to put on the rotary?

It sound like you have the basic requirements set…

Try this… if the motor driver is set to 5000 steps/rotation, you can set that value in the rotary gui for steps/rotation and watch the motor… the motor should rotate one rotation and back… with the gui test button.

If that works it’s your ratio between motor and chuck. If you can’t get the motor to operate one turn and back it’s not going to work at all…

Stick a piece of tape or something on it in a way it won’t interfere with the belts or anything so you can tell if it’s working correctly.

Make sense?


Thank you. It did not work. I can press the Y arrow button and it moves. So weird. It goes fro 0 to 498 mm. Which is several rotations.


You are correct, a graphic did not show on the interface, it was to draw a small line.

I so appreciate your time. Do I need to buy a new rotary or another stepping motor to install on the U axis?

Did you do the rotary setup in Lightburn? That’s where I was expecting you to set the steps/rotation…


I assume you mean either that it did not move or it moved incorrectly?

What goes from 0 to 498?

My machines console looks totally different… :crying_cat_face:

It should work… don’t replace things unless you have a reason. You may end up with more problems than you started with…


I have done it from the Computer GUI, and it will move, just not correctly.

It’s CHIEFS football time!! I’ll go out to the workshop during halftime and get screen shots.


WOO HOO TD! Anyway…That is what I was showing in one of the videos.

This is kind of key, how does it move that is incorrect. That can be helpful in diagnosing this…

I’d rather fix this through Lightburn, I’m unfamilure with this console and it’s nomenclature.

Congrats on the TD :+1:


Here is from the LB software. The TEST button does move the Rotary, about 2.25 times. Video link below.

The chuck or the motor… we were targeting the motor


I am not sure how to tell the difference. The rotary has a motor. It is plugged into the Y? The rotary chuck rotated, I am not sure if the Y stepping motor was engaged? How do I trouble shoot it?

I have circled the motor pulley… it’s tough to see, but you can mark the edge with a marker or taper or whatever…



gotcha. I put a small piece of tape on the belt. It rotated 1.5X.

I am only allowed to make so many posts in a day. So I am trying to edit one to answer your last question. :slight_smile: Just verified the switches. 2,4 and 7, is what I see. Am I reading it correctly?

Are you sure you have the on side in right direction with the motor driver switches?

On is toward the circuit board or down in the photo. We don’t all do everything the same way… they read right to left …

If I take 1/1.5 = 0.6666, then 0.6666 * 5000 = 3333.33

If you have mistaken the on/off directions on the motor driver it would be 3200 steps/rotation… inverting all switches… it would make sense.

It probably didn’t do exactly 1.5 turns, but this would be a more logical explanation for the results you’re getting…

I’ve done the same thing… so I’ll move over, there’s room in this same boat for all of us… :crying_cat_face:

You need to fix this… you’re running me out of ideas :crazy_face:

Good luck


Following along Madam Tinker
Agree with your math although visually the pulleys look like a bigger difference.
Agree 5678 off off on off = 5000 and your photo looks correct
Agree changing the diameter should not affect the 360 rotation when you hit test.

It would be more simple to just enter the 3200 steps/rotation in Lightburn and watch the motor pulley…

Probably more simple than crawling around trying to read the configuration switches.

It always annoys me, with all the technical data they give you, motor phase, torque etc… with these rotaries, but leave out the gear ratio… Something simple for them and a pain for the user.


I agree with the annoyance…
EZ has a ratio field, why don’t we… Anyway, looks like the crawling around has already been done if the photo was the correct microstep driver. What is a reoccurring theme is the revs seem to change based on diameter, which it shouldn’t whether the ratio was correct or not. Similar to the other posts mentioned. Something else is going on, way over my head. Just following along for the education.

Depends on which device you look at… I’m starting to wonder if the motor driver was installed later and/or never setup properly with the controller.

It sure is shoehorned into the area next to the power supply…

These are assumed to be setup when you buy the package, but I’ve realized the truth about these, you sure can’t count on anything being correct.