Help with wiring up my nice new rotary

I have a Gweike 1290 with an 80 watt tube. Inside the laser on the right side is a silver 4 pin connector (with only 3 wires) it controls the Y axis.

Board: I believe the board is a Lethro DSP.

I currently use Lasercut 5.3. I tried using Lightburn, but it said I was missing a DLL or something like that’

Problem/ Question: I just received my Nice new Rotary attachment and I have questions about how to hook it up to my machine. I was really hoping it would be plug and play it seems like I was wrong.

Ps: I will send pictures of my controller later after I pull my laser out.

Yes, pictures of the electronics will be great and we can take it from there.

Your machine is wired for 3 phase stepper motors. You might need to swap the stepper motors on the rotary unit for 3 phase variants or add a second stepper driver for biphase motors in parallel with the stock one, then have a dedicated connector for the rotary to use.

Yes, 3 wires going to a motor is not what we are expecting, as the rotary uses a 4 wire Nema 17 Stepper Motor. It does sound like your machine has 3 phase motors with different drivers to match those.

Unfortunately I am not able to understand the current wiring from the pictures you have provided, it would be good if you can provide clear pictures of the driver including the wiring coming out of it, pictures of your motors themselves, the entirety of the electronics bay in the laser, and the model # of the motor drivers.

I will be happy to assist you from there.

I will see what I can find out. If I can’t figure this out or if I have to spend more money on a new motor I would just like to return this product. I will try and get more pictures.

Hi Bruce,

We do not need you to replace any motors. You will most likely need an additional stepper driver, and wire it in to your machine. I’m waiting for the pictures so I can advise you on this.

A lot of rotaries use the same motor and thus would have the same requirement to get a separate driver installed

For what it’s worth:
Cohesion3D is one guy named Ray. That’s me. Hi! Trashing me on Facebook is not going to get you up and running any faster - I put my soul into this business and I’m really trying to help you.

The forum is the best way to discuss technical matters such as these, so that we can share pictures, link documentation, and have other knowledgeable people weight in where needed.

As I said, trying to help.


Okay Ray, I was out of line and I apologize! I am just frustrated. I am on a fixed income and had to dig a bit to buy this Rotary. I was naive and hoped it would work right out of the box. It didn’t so the only place I could find support was your forum. the first response said it was from a robot from C3d. Then a few days later a user responded and said I had a 3 phase system and that I would probably have to buy a new motor for the rotary but not a real fix.

Part of my frustration stems from trying to get help with LightBurn. A month or two ago I tried to install it and had issues. Only place to get support was the forum I never got any responese. I figured it would be the same with the rotary. I am an older guy and I am use to picking up a phone and calling someone for help or at the very least logging on to the company website and filling out a support request.

Again I was out of line and I will delete my post on your FB page if haven’t already.

Ok Ray, I am interested in the different stepper driver. What do I need and how is it hooked up? I will try and post a few pictures.

Ray, I realize that you are a one man company and you are doing well with Lightburn and now the rotaries. Like I said earlier I am an older guy and I am use to calling a company and talking to someone in support or maybe even an online chat. I’m computer and electronic challenged and I just don’t think this rotary is going to work for me. Is there some way I can return it for a refund?

Yeah, this is definitely a 3-phase machine.

Wiring a second motor driver in parallel with your Y-axis driver will be the easiest way forward for you.

You will need to buy a biphase stepper driver (Cohesion3D sells a decent one and it’s guaranteed to work, otherwise look for a Leadshine elsewhere - should run less than $40 to your door).

You will need to add jumper wires from the existing driver’s control signals to the new driver’s control signals. You will also need to add jumpers from the V+/V- terminals to the new driver’s V+/V-. In this setup, you have two motor drivers running from the same controller. It would be worthwhile to add a second connector of some sort to connect the rotary stepper motor as-needed.

When you want to drive the rotary, you will disconnect the Y-axis round connector as pictured above, and plug in the rotary to the new connector. After positioning the y-axis gantry at the right position everything should work as necessary.

Also note that Ray doesn’t write Lightburn - there’s a separate forum to discuss that on the Lightburn website, and the lead developer is very responsive and helpful. In fact, he monitors this forum as well and may be able to help or direct you to the right place.

Good luck!

@loather thanks for this write up, hopefully it will help future people with similar set ups.
In this case, Bruce and I worked out an alternate resolution.

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