I have been turning cups for a while now with no issue with my settings in Light Burn. Today I finished up some 20oz cups, and changed everything over to run 30oz cups. Same cups I always run. I put in my settings for the 30oz, ran a move test and it is not hitting on the mark now. It is doing 1 1/2 turns. I am unsure if I click on something I havent before? Something? I have looked into everything I can think of and can not find my issue. Could really use some help. Thank you
What kind of rotary are you working with and which settings did you change?
If you have a Roller rotary, but you selected Chuck in the Rotary Setup window and adjusted the Object Diameter, that would impact how far your rotary turned. With Roller selected, adjusting the diameter will make no difference.
If you adjusted the steps per rotation setting, you should revert it back to what it was before, or, if you can’t recall that value, adjust it until the Roller or Chuck (not object) makes one complete rotation before returning to the start position.
4 wheel rotary, I have rotary selected. I have written down my steps per rotation for each size cups I use. My 20oz is 2680.00 my 30 oz is 3058.00. I have a ton of tumblers with these numbers with no issues. I set up for my 30oz with the 30 oz numbers and it is over rotating. What is the “distance” in the move tab? I know that number seems to be different than what it was.
The distance in the Move tab is jogging distance - it won’t affect your rotary.
Steps per rotation is not a value you should be changing each time you use your rotary - it should be set once for your rotary and not adjusted after. Making sure to select ‘Roller’, input your roller’s wheel diameter, and then adjust the steps per rotation value until the wheel (not object) makes one complete rotation before returning to the start position, when you click the ‘Test’ button.
Yes I have the roller diameter in, it is 67.600mm I did the test button and it stops where it started. But I haven’t changed that number. I guess I’m totally confused now.
Once you’ve entered the correct roller diameter and the steps per rotation value that causes the roller to make one complete rotation before returning, click ‘Ok’, and then restart your controller, to make sure the change takes effect. You should never need to change the steps per rotation value again.
Then try engraving the tumbler - bear in mind that you should not expect the tumbler to make a complete rotation before returning to the start position when you hit the Test button.
Okay, thank you. I have it and it works now. What I don’t understand though is how did I get it to work the way I was doing it? I found a video on YouTube that explains it the way I was doing it.
In my head, I don’t see how this works for a full wrap. Wouldn’t it take less rotation for a 20oz then a 30 oz? Or am I over thinking it?
I’m not sure how it was working the way you were doing it either - although that was only working until it wasn’t, of course. 
It will take less rotation to wrap a smaller tumbler than a larger tumbler, but it will always take the same amount of steps to rotate your roller’s wheel one complete rotation. The rotation of the wheel is transferred to the object. Your graphic in LightBurn should be larger to match the larger circumference of the larger tumbler, and then the roller will turn more to account for that.
I have a PiBurn for my co2 and a rotary for the fiber, but I can swap them… use either with either machine.
The basic setup from a low level view is to turn the motor one complete turn. My chuck type directly drives the chuck, so one turn of the motor is one turn of the chuck. So the steps/rotation are on the motor driver that drives that axes.
If your chuck or rotary has a belt/gear drive between the motor and the wheel/chuck you have to compensate for the difference, you want the chuck to turn one complete rotation. If the motor turns two times for one turn of the chuck you’d have to apply that to the steps/rotation of the motor because the motor has to make two turns to turn the chuck once.
If the motor takes 5000 steps/rotation and it has to turn twice to get one turn of the chuck, the steps/rotation is 10000.
Same with a wheeled or roller type… the end is to get the driving wheel to turn one complete turn. My piburn has 2000 steps/rotation (set on the motor driver), but I have compensate for the 2.5 to 1 turn ratio, so my steps/rotation are 2.5*2000 or 5000.
I’ve seen machines that run long pieces of material to get lased. The work just like the rotary, the roller just rolls the material through the machine… same as rolling a mug or cup it doesn’t know or care…
What I’m trying to point out is from the controller to the motor is digital, so that is exact. It’s the power train from the motor to the driving wheel/chuck that can vary. The rollers may be a different size than that specified by a vary small amount and affect the rotary.
In the end, you can adjust the steps/rotation and do this or the ratio of the motor to the roller/chuck.
Did this help or hinder?
Good question, there are lots of variable… You have to tell us…
If you change steps/rotation you change the surface speed which is the speed between the head and the material move by each other… or generally regarded as your engraving speed, such as 100mm/s. In industry, both the head and the material may be moving simultaneously, so the distinction of surface speed is used.
Let me ask you a few questions…
- are you doing the same operation on both sizes of mugs?
- are the laser settings of speed/power identical?
- is the same coating and metal for both types?
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