Is there any chance that this unit has the wrong belt? There exist similar-looking GT2 2mm and MXL 2.032mm (0.08") pitch belts. Furthermore, 2 / 2.032 = .98425196 which looks suspiciously close to 98.6% — within measurement error perhaps.
If you feel confident that it’s not a hardware issue, have you tested with different software? Do K40 Whisperer and Meerk40t have the same issue?
Did we consider this clue above? Are you cutting on the inside or outside of the shape? The beam does have some kerf.
1 -.986 = .014/2 = .007
All I can say is that it’s the same belt as when I purchased new.
I’m not familiar with the other software. I’ll study up and give them a try. But, if it’s only software (and it’s CorelLaser I’m using), surely someone else has experienced this issue? Is it possible people rarely cut where absolute accuracy is important?
The error is not fixed, but directly proportional to the length of the line. This fits the wrong belt, except that why wouldn’t engraving have the same error.
It’s been a long time since I posted that info on the other forum. I’m going to recheck again (engraving versus cutting) just to make sure.
Is it feasible to measure the pitch of the belt without removing it from the laser?
That sure does sound suspicious, but if the belt was wrong it should affect BOTH engraving and cutting, right?
It’s as if the cutting portion of the software has a different notion of the belt pitch than the cutting portion. But, there aren’t separate settings for the K40 in engraving versus cutting tabs.
I confirmed the engraving versus cutting issues by creating an 11" x 3.5" rectangle ( just the biggest scrap material I had on hand). on one layer in CorelDraw. On another layer, I put a small square in each corner of the big rectangle.
I first cut the large rectangle. Then, without moving the head, I engraved the four smaller rectangles. Here’s what it looks like:
The small rectangle location and sizes are exact, at least to my ability to measure them with my caliper. But, the large rectangle measures 11.15" x 3.55" (too big).
This really seems like a software issue, but if so, why isn’t this a problem for many, many people?
Tomorrow, I’ll research software alternatives.
Is there a way to check the main board model? I’ll have to do a little disassembly to see the board–if I do this, will there be identification on the board that could confirm that I have the right model selected?
How would that name be used to determine if I have the right “model”, eg
6C6879-LASER-(A/B/C/M/F/K/L) SERIES
(That’s what’s in the settings in the laser software)
Actually, I see this in your pic:
6C879-LASER-M2
I’ll open mine up tomorrow and verify the number. If it’s something inconsistent with 6C6879-LASER-(A/B/C/M/F/K/L) SERIES, maybe I can change it to resolve the issue.
If it’s consistent with 6C6879-LASER-(A/B/C/M/F/K/L) SERIES, maybe someone would volunteer to try this experiment. I can upload the .cdr file.
Or, indicate that you know you don’t have this issue.
Thanks!
For alternative software, the K40 Whisperer and Meerk40t categories here are dedicated to and moderated by their respective developers.
I have WAY too much invested (both $ and time) in CorelDraw to design in something else. But, I took a quick look at meerk40t and it looks like I can import a .svg file that I export from CorelDraw? That’s fine.
Probably a fast path could be implemented by CorelDraw macro, if I find out this resolves my issue.
Thanks!
Can you try this just straight in meerk40t (can run along side the chinese software no need to mess with drivers). Load up the terminal (F12) and type “rect 0 0 6in 6in” that’ll give you a properly converted 6in square. You can then compare that with your expected values and see if it’s hardware or software. If that also is wrong, I’d suspect your x-belt is a little bit stretched. It sometimes happens. But, I’d rule out the software first since you have a couple conversions. Coreldraw to hpgl which is like 1/40th units to the chinese software, and it wouldn’t be too hard to have rounding error in those cause an issue.
Yes, I’ll try that this morning and report back.
It’s not just x, but both x and y. And by the same amount.
Wouldn’t engraving be impacted just like cutting if it was a stretched or wrong belt?
But, I’d rule out the software …
I think you meant
I’d NOT rule out the software
meer40kt looks awesome!
But, I’m going to have to read a bit to get it working. I can get the 6 inch rectangle easily enough, but there’s no communication with the K40.
Not asking for help yet, since I’ve never even heard of meer40kt until last night. But it looks like its worth the time to get working, regardless about what I can figure out about the accuracy issue.
I did check the board version:
So, it seems consistent with the model setting.
Ok, maybe I WILL ask for some help.
I couldn’t find documentation on how to use the meerk40t GUI. I played around with i,t but could never get anything but “beep” in what I’ll call the job window.
What exactly should I do after creating the rectangle? Or, can you provide a step by step to verify things are working? Or, point me to something that explains it?
Thanks!
Ok, found some videos. I’ll go through those.
Ok, meer40kt elements versus operations. Just drag the element in the operations area, under cut.
The 6 inch square rectangle is cut precisely–exact to my ability to measure.
So, this says the issue is definitely software. Is there some setting that could fix it?
Or do I choose between always scaling by .986 versus using different software.
I guess my next step will be to figure out the workflow from CorelDraw to cutting. I really just want the ability to set speed and move the head freely. Then start cutting (inside out) from where I positioned the head (just like I do today).
Maybe I should ask this somewhere else, but what are the steps needed, and can I script them to make the workflow as painless as possible.
Although some users have powered through …
These kinds of software problems are why I immediately moved away from the stock software.
Expect to continually have this kind of problem :(.
I would advise you invest in one of the other software offerings and even a new controller 
