Steps per rotation for laser rotary setup
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- เผยแพร่เมื่อ 17 พ.ค. 2020
- In This video we will go through the process of determining how to set the steps per rotation for your rotary device. There is allot of ways to do this I illustrate just one way to get it close. The Test feature in light burn does not work properly on my laser so this is what i came up with. Below is a great video if you can use the test feature for the rotary in Light Burn.
Test Function setting up Rotary in Light burn
• HOW TO... Rotary Test ...
So one thing I see in a lot of these rotary setup videos is much like what you did in yours. When you run your first test of the circumference and see that it overshoots or undershoots the mark, you then take a guess on the new steps per rotation and test again, and you keep doing that until you find a value that works. There is a formula that is used in the 3D printing world for calibrating the steps for the extruder. For that they start with an arbitrary number of 100 and measure 100 mm of filament. They make a mark of 100 mm on the filament itself and then tell the printer to extrude 100 mm of filament. They then measure the actual amount extruded and use this formula:
([steps/mm value] x 100) / [actual length extruded] = [accurate steps/mm value]
So to use that in this context, you would use this formula where you are replacing the 100 value with the circumference value and measuring the actual length moved:
[actual length moved] = [circumference] +/- [overlap/underlap]
([steps/rotation] x [circumference]) / [actual length moved] = [new steps/rotation]
Now filling in the values based on your guess of being about 1 inch over on the first run, you would get this:
(4400 x 12.5) / (12.5 + 1)
55,000 / 13.25 = 4074.1
That number would have been closer to the exact value needed had you measured the actual amount that you were over with your caliper and not guessed at 1 inch, but as you can see, I got close to your end value of 4075 on the first shot and didn't have to take multiple tries to get there. I don't know if you would want to make an updated video using this information, but as you can see, this calculation clearly beats the guessing method that everyone uses to figure this out. Using exact measured values probably would have gotten you to a more exact value than what you got in your video Looking at your end result, you were REALLY close, but still a tick off.
Curious on your comments.
In case you're interested, here is a link to pictures of some of the DIY machines and rotaries that I have designed and built.
dan.bemowski.info/image-gallery/nggallery/3d-printing
Dan Bemowski
appreciate your comment
Exactly the Math I was looking for. Basically, it boils down to this formula. We need to divide the pie based on Surface Feet per Rotation for every circumference. Thank you! NOBODY talks about the math behind this...not the manufacturers, or the tutorials. Why can't they simply build that formula into the query on the diameter of the object?? Perhaps a 'test fire' option with a window for 'difference +/-' value to input that would automatically correct the steps per rotation, projected vs actually.
You’re the best. You’re videos helped me so much since I got my thunder, and rotary. I cannot wait until my cutting boards are finished in an hour to go finally get this rotary set up perfect. Thank you!
it’s worth doing. I do allot of full wraps and without accurate steps you can’t do something line this!
Thats some great advise...this videi is saved for future recerence...great work!
Glad it was helpful!
thxs again my friend. you have become the main reference.
I appreciate your comments and that my videos are helping you out.
Great help! Thank you.
You're welcome!
Great video, thanks!
Glad you liked it!
Another great video!
Glad you enjoyed it!
Can you help i have setup my roller put in all the settings and when I try and do a test fire my laser keeps running on the y rail and won't stop
Great video...very informative! Quick question, should I have to recalibrate the steps with every different sized cup or just the initial calibration?
If the diameter of what you have on the drive wheel of your rotary is a different diameter than your engraving surface then YES it will be different. good example of this would be a sports bottle. the neck that's on the drive wheel is 2.75" but the engraving surface is 4" in diameter. This will have to be recalibrated for that setup.
Thanks!
Erick, thank you so much for your contribution. I really appreciate it. I use this money to better the content on my channel.
Thanks for all the help in your videos .. quick question. Do you have to set up steps per rotation for each different size cup i.e. 12 oz , 20 oz 30 oz?
if the diameter of what you put on the rollers of the rotary is the same as where your engraving then no. but if that number is different you will have to recalculate. see my latest video on doing a 1 gal jug where I go into depth on this subject. thank you for watching
Thank You. Just purchased a laser cutter with rotary - brand new to this idea. This was a great video. -- Question: The blue tape - when you're testing - is the laser cutting through the tape and marking up the tumbler? Thinking of waste cost. Thanx in advance
No I put the tape,on the tumbler and turn down the laser. That way I don’t ruin a tumbler. The tape absorbs the laser energy instead of ruining a tumbler. Thanks for the comments I appreciate you watching.
Watch my very latest video on engraving a 1 gallon jug and go into depth on when you have to adjust your steps.
Thanks for your video, it has cleared up important doubts for me.
What type of rotary you recommend for CO2 60w laser, similar to the one you show in your video?
Thanks for your instructive videos
I use a rotary by rotoboss, I feel it’s the best one out there.
both Rotoboss and piBurn are about the same price. I would interact and see which one provides better interaction.
Thanks for the great vid it really helped!
Question do you do this for every diff size mug ? or do you know if the rotation is the same for diff sizes or or even for glasses? like if its 1000 per rotation is the setting that would work for mugs or glasses ?
In a Chuck style rotary you won’t have to change. On a roller rotary as long as what your putting on the drive wheels of the rotary is the same diameter as what your engraving you don’t need to change BUTthe minute what you have on the drive wheels is different that where your engraving you need to determine steps for that set up. Good example would be a water bottle. Alomost always the neck you put on the rollers is different diameter than where your engraving.
Wonderful Video! One question, how would you go about finding the suggested steps per rotation from the rotary distributor? My rotary came with my laser so I am not sure what brand it is?
Thank you for your comment, if your rotary came with your laser, your laser company should give you a starting point!
Hi! What is a good lower fill setting for the tape? I have a 35-80W. Thanks!
I’ve got a 35-100 and use 400/10 for marking blue painters tape
Thanks for the video! do you have to do this with every size tumbler? Switching from 20 ounce to 30 ounce?
Hi Heather the short answer is not if what your setting on the drive wheels on the rotary is the same diameter as what your engraving there is no change. But if in the example of a sports bottle where the smaller neck is put on the drive wheels on the rotary and it’s smaller or bigger that where your engraving you must recalculate your steps.
What would you say is the issue if they aren’t lining up top and bottom? I have ensured the rotary is straight across in the laser. JDS 20oz tumbler & I have it set to 3.5” diameter.. lines are ending at different heights
Two possibilities either your rotary is not parallel with your gantry or your tumbler is wandering in the rotary.
How do you stop it wandering? I’m trying to engrave a Stanley with tabs and I can’t put it all the way to the top because of them.
Thank you. I'm running into issue of steps per rotation. I've filled in "Roller Diameter", "Object Diameter" and "Circumference" -- Regardless of what the number for "Steps per Rotation" is - the tumbler still turns a full 360° (4) times. Whether it's at 4400 steps or 200 steps. Thoughts? TIA
Hmmm I haven’t heard of anything like that, sorry I’m not more help.
Did you ever figure this issue out? I am having same problem.
Another great video. I have a questions. once you have determined the steps per revolution do you have to adjust them as the Tumbler’s size change or they stay constant?
If the diameter of the top of the tumber is the same as where your engraving then you dont need to no matter the size but the minute you goto a water bottle where the neck is smaller that the area engraved you need to recalculate or purchase a donut style coller so you can keep the same steps
@@computercreationz thank you for your help
just to be sure……as long as the tumblers have the same dimensions throughout the step per revolution should be consistent, right? But, If I change Tumblers size or the dimensions is not the same ( top to bottom), I should always recalculate the steps per revolution?
@@computercreationz question
Wouldn’t the step per revolution be determined by the diameter of the rotary unit rollers independently of what size tumbles is being used?r
Just asking,,,
Robert, do I need to do a steps per rotation calibration for every different size cup I do?
Only if the diameter of what your setting on the drive wheels on your rotary is different than the diameter of what your engraving. Example a water bottle has a 2.75" opening but where you are engraving is 4" in diameter. This would have to be recalculated. If what your setting on the drive wheels is the same diameter no need to recalculate!
Why when I use rotary chuck attachment my laser engraving "invert-mirror" image...I need to manually before start horizontal mirror image to get what I want...
more than likely you have your machine origin set incorrectly
I've got my Steps figured out. My questions is if I'm engraving a circle why is it oblong in finished product?
Hey Rick, it an optical illusion you need to stretch you round design 10-12% horizontally for it to look right.
Great video. I don't own a laser yet (on order from Thunder) so a very raw rookie. I have several questions:
1) I don't get the relationship between taking the diameter of an item and also having to set the "steps per rotation". It would seem that setting the diameter would be all you would need for each size of tumbler but it appears that it is really the "steps" that dictate.
2) Is "steps" only a concern when doing designs on two sides of a tumbler i.e. if you're only doing a design on one side, do you even mess with the "steps. Thanks.
congrats on the new laser, you will love it!
Well, one would certainly think! My point in the comment above as well. So, we agree! Basically, it IS two different issues, but there is no reason why it couldn't be merged via some background programming.
Being a 'step' motor operated device (all CNC's), they make a 'step' for every particular infeed of voltage/amperage. Different motors have different step ratings. That motor may move the projected amount, or it may not. This makes no sense from a precision standpoint, but fortunately, they generally do. If it doesn't then you can't fix the motor as it is what it is, so you just adjust the 'actual' and forget about the 'theoretical'. The quirky problem comes when you add a varying value such as different size diameters of different cups. (The bed of the laser never changes thus, X & Y axis are always consistent movements 'per step'.) While the surface feet should translate no matter what, the curvature makes the object being lasered a radius (it is not flat). Thus, the software has to compensate for this 'distortion', hence the 'diameter'. Case in point: laser a 4" cup, then insert a 3" cup without changing any setting, you will see the distortion. 'Steps' basically boil down in 'degrees' per rotation, albeit much, much smaller. The default setting in my laser is basically 17.77 steps per degree of rotation. We know 360* equal a full circle, but to that chuck that 360* is being created by 'steps'.
Again, it boils down to surface feet. A different diameter means different surface feet, meaning the design has to either be spread out or shrunken down to stay to scale. The step value is what controls that shrinkage or expansion.
So, we are still back to your main point. They should be able to COMBINE these with a little math so we are not trying to sort it out later. Not sure why they don't do programming on the back end for this?
There is a wonderful post above where Dan gives us the math. Surely the programmers could just build that in, still allowing for manual correction when the math fails in the real world (as it will). 🙂
@@anthonyobrian2665 Excellent reply...thanks for all of the detail!
Forgive me for the dumb questions, lol, but...the tape. Do you put this on, and then use lower settings, so it just marks the tape, not deep enough to burn onto the cup, so as not to waste a cup figuring out correct settings? Follow that!? LOL!
Yes that is exactly what you do. Great question, I use this method If I not sure of place t on a tumbler or how a design looks on the tumbler.
Will a tapered tumbler make a difference in steps?
it can, depending how severe the taper is!
does that mean every time i change to a different diameter item i have to find the correct steps per rotation as i have watch a few videos on this subject but getting conflicting answers any help would be appreciated
no as long as the diameter of what you your putting on the drive wheels of your rotary is the same as what your engraving you don’t need to change. you do have to change and figure different steps per rotation if you have a sports bottle where the neck is smaller that the engraving area. it’s a ratio thing
@@computercreationz sorry I am a bit lost so if I have an item that is 80mm diameter engrave that then I have an object of 120mm diameter I then need to calculate new steps and write that to the controller cannot do it in software alone ???
@@warriors475 if what you put on the drive wheels of the rotary is different diameter than what your engraving new steps will have to be recalculated.
@@computercreationz there has to be some kind of math equation you can do once you figure out the diameter for one cup, that you can just take that diameter or circumference and it steps per rotation to it figure out the steps per rotation for the next diameter objects, I'm the math expert but surely there's some kind of algebra or something that can be done, at least I would guess and hope so?
Once again you knock it out of the park; thank you! Questions - once I have my value, does it stay for anything new that I engrave, or must it be determined for each new diameter of object? Also, do you have to press the 'origin' button on the machine each time? Is there a way of re-homing the laser head to the origin point when it's in Lightburn's 'current position' mode? I don't have a 'home' button on my newer control panel like the old ones do. Thanks!
Hi Jo, yes the steps will stay the same as long as the cup diameter that you engraving on is the same as what you input into the rotary information. You will always have to feed in your cup diameter or Circumference for every cup you do.
With that said if you have a sports bottle and the neck of the sports bottle is 2.75" in diameter and that is what is going to set on the drive wheels of your rotary. But you engraving surface is 4" in Diameter then you will have to calculate different steps per rotation. The reason is the ratio between the 2.75" neck that sits on the drive wheel of your rotary vs your engraving surface.
Another great reason you now know how to do this!!!
Once you have your rotary set up you should move it until your done with doing cups. So you establish you user origin only once. You would have to do it again when you use the rotary again. Remember you have to align it along the x axis and that is slightly different every time you set it up. I find it easier just to re establish a new user origin.
@@computercreationz Thanks, that's great info. I was moving the head out of the way along the X axis during testing, I guess I'll just manually realign it each time, then, and hit 'origin' again. Whatever works :-)
@@JoHunter Hi Jo you shouldn't have to do that. Once you hit origin on your controller you should be good. Once the cut is done drive the head out of the way. Reload new cup. In lightburn go to "Go to Origin" next to the Home button in the laser control panel in Lighburn. Your ready to start the next project!
@@computercreationz Thank you.
Wouldn't be easier if you put pencil mark on the cup and use the "test" feature in lightburn and have it rotate 360 degrees. If your stepsister rotation is correct it should stop right at the pencil mark.
Unfortunately the test feature doesn’t work on allot of rotary’s. But if the test feature does work that would be one way to do it!
well I love your videos you make it seem so easy so i bought a rotary attachment for the OMTECH 150w sitting in the garage. Im having problems. engraving on a pub glass and the design comes out correct dimension. but the quality looks absolutely horrible. there are vertical lines going through it and all the edges are uniformly wavy. I have increased the LPI and DPI with no change. slowed it down, speed up, threw at the wall hit with a hammer, all same outcome.. Have you every had anything like this?
Most of my glass engraving is done at 400 mm/s at 15-20% power on y 100 watt. Lpi at .080 or 317. I always de focus my lens 2 mm . Works pretty well
No offense. However I do find it entertaining that you have a nice laser made in the US but you’re using a harbor freight caliper. 😮
Thanks for the video though. Just got my rotary.
No offense taken, the laser is from China too lol
I'm sorry but you doing it almost completely wrong. First steps per rotation is determined by stepper driver and gear ratio of the rotary. For example if stepper driver is set to send 5000 pulses per full rotation and your rotary has gear ratio of 2.5x your steps per rotation will be 5000*2.5=12,500 (just as an example). So use that number as your starting point. Diameter is the actual diameter of rollers wheels on the rotary. Measure them and put it in the settings. They stay constant no matter what cup diameter you are using. You don't need to burn anything, just use "frame" function. Your speed is insanely fast, it causes cup to jump and skip so you'll never get an accurate measurement. Slow it down a lot. Otherwise yes you can keep changing step values to fine tune distance, but you can also play with diameter settings instead.
I think we will agree to disagree. the starting point for the manufacturer of my rotary is 4400 is I used your methodology I would go around the cup 2.5 times. getting accurate total steps on a rotary will very by manufacturer so one number does not fit all. Thank you for your comment and have a great day!
@@computercreationz This might be because you had incorrect diameter in the settings (from looking at your screenshot you have it set to 1.62" (should be around 2.32"). But whatever method works for you. I would slow down the speed tho, you can see cup is bouncing pretty hard... Thanks for the video!