Wobbly lines using my chuck rotary.ut

Brand new chuck rotary. Quality checked by supplier. In the image you can see that on the letters there is a distinct wobble running throughout the engrave. Ive tried slowing my settings no change.

My step settings are 10000 which i thought was high compared to what ive seen but my line up is perfect. 350mmps 60% on a 50watt chineese co2. Tested engrave on flat plane and no wobble.

Is the chuck faulty. Was packed and sent accross the country with minimal padding ( very poor) could it have been damaged?

Is the rotary Chuck belt driven internally?

I’m suspecting that the mechanism is telegraphing a mechanical property like an internal belt or gear tooth pitch.

How many DPI ( or what line interval ) are you engraving at?

Looks like it occurs when you are traveling in other than vertical or horizontal dimensions…


I suspect it’s being engraved back and forth and the wobble is belt tooth lift.
Waiting for confirmation.

Hi John, Im really what the internals look like, Ive attached a link ( Standard CO2 Chuck Rotary - Koenig Machinery ) I had to set my Interval down to 0.30mm to get a clean engrave, I do want to have play with my focal length and see if i can get a clean engrave with a interval of 0.60mm or higher otherwise engraving just takes forever, it a bit of a win or loose because of the taper to the cup and i want to engrave both high and low parts without having to do it in 2 goes.

Really not sure what that means?

Yes, you can see from the image my set up engraving back and forth on the x axis, Ive even turned bidirectional fill off slowing my output further as i was getting a slight blur when i had it on (any suggestions to why this occurring as well?). Tomorrow Im going to move it across to my other laser and see if the same problem occurs, i would like to set up this one being the small laser as a permanent rotary though.

That looks like a belt or gear driven rotary. The stepper is not connected to the chuck directly.

On my 60w I use the following.
250 mm/sec
0.04 DPI
22% hi and low power

Assuming it looks something like this.


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Okay Ive got my power set quite higher than that. As i mentioned I would love to do bidirectional however I have an alighnment issue and get a double image. Ill try those settings and see what results I get.

Really appreciate all the information. Your set up is more what i would like to have for doing rotary engraving. However not sure if its relative to the issues im having as i have a different style ( a chuck rotary) unless you just like bragging, nothing youve said has been of any help at all.

The blur could be backlash or scanning interval.
Have a look at this thread to see if the blur looks like this.

This video from Russ Sadler talks about the acceleration and deceleration of the head caused by the belt drive. I’m curious if the wobble in the drawing coincides with the tooth interval distance on the chuck motor drive pulley multiplied by the ratio of the pulley diameters.

Reversing the belt as Russ’ solution:

I’m thinking it’s this because of the shape of the wobble.
See how the down-arrow absences land between the up-arrow absences.

I think it’s speeding up and slowing down.

Hi John!

Thanks for sending this through as I’ve spent the last week watching these videos and have been in touch with Russ for a solution to my issue, I think ill be spending a lot more time watching his videos and modifying my machine to be honest, kind of a falling down the rabbit hole situation haha. I’m sure all the effort will be worth it. Ill be back with an edit in the future whether this has fixed my issue. Thanks again.

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