Snapmark alignment always .35mm to the left of center

I made a 7in wide template for earrings. I scored the snapmark alignments and lined them up on the center line of template. When I use the template the resulting score marks are exactly .35mm off of center every time. In the Inkscape SVG file the markings are center aligned exactly. I confirm that the template is loaded correctly on screen and I have tried redoing the template and re-uploading the file with the same results. I removed and cleaned the bed to make sure there wasn’t some debris causing a slight angle. The odd thing is that the template seems perfectly repeatable after being moved but there is still this consistent error that I can’t track down. Normally this amount of error would be tolerable but it is noticeable on the small earrings.

Guessing there is nothing I can do about this other than compensate for the offset in template but hoping someone might have another idea.

Snapmarks are no longer supported by Glowforge…as of sometime in 2019, so unfortunately, you won’t be able to get any help with this.

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I hope that this isn’t true. Snapmark is still a listed feature in the support documentation and camera calibration doesn’t solve the problem of lining up a jig/material with a pattern predictably.

With perfect positioning you can go into that and move the design 0.35mm over. Snapmarks is a “has been” piece that was supposed to be gone and few of us still have it, but no longer supported I think. There are now many other things that are suppose to replace it but I find it the best way to get precise rotations.

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Sorry…but it’s true. I have snapmarks, too…and I know there are a few people who still use them, but support won’t be helping with any problems associated with that feature anymore.

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Snapmarks were never officially supported. The page you linked to even says beta.

It was a stepping stone towards the “calibration” process. For those of us lucky enough to get them, it was a handy tool, but there was never any promise of accuracy, reliability, or permanence.

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Thanks for your interest in Snapmark. Unfortunately it is no longer available for additional customers to receive access. We recently announced that we’ve stopped work on Snapmark but more importantly, that the work on Snapmark enabled us to provide the new lid camera calibration tool.

I notice you haven’t tried the camera recalibrator yet. I’d definitely recommend giving that a try first.

The details can be found in this support article:
https://support.glowforge.com/hc/en-us/articles/360033633714-Alignment#camera-calibration

If you’re still having alignment trouble:

  • after running the camera recalibration
  • while using Set Focus

Send me screen shots along with the time/date of the print. I’d be more than happy to check the logs and see what I can find out.

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Unfortunately none of these suggestions actually solve the problem. What you are saying I have to do is rely upon the screen image in the app to align a precision cut/etch. The screen alignment is never good enough for this problem. Do you have actual numbers of what the screen alignment should be able to achieve because I have never gotten it better than 3mm off of actual.

The snapmark was designed to solve this problem by bypassing the user UI for alignment and fully automating the problem. Really disappointed in Glowforge that they abandoned this one piece of computer vision tech that made a difference.

And before you ask, yes I have run the calibration tool. I don’t know what you are referencing when you say I have not. I printed the whole sheet of markers and aligned everything last spring. Didn’t help with the visual errors.

The published specs are for about 1/4" (6mm) so if you’re getting 0.35mm, you’re doing pretty good.

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Published specs for what are 6mm? The UI alignment?

Yes

Things have improved amazingly in the past 5 years. For much of it, I would do a very light test cut and then adjust the same distance in the opposite direction. Even back then as long as you did not change the position it would cut in the same place time after time.

Even using Snapmarks, I find alignment can be off by as much as an eighth of an inch (~3mm). With a calibrated machine, working in the center, right under the camera, I consistently do at least as well, if not better.

One thing that sometimes helps is to add your own fiducial marks at three points at the extents of your project space. That generally catches x, y and rotational alignment.

Unfortunately, even a few tenths of a mm in misalignment is a problem for some of the stuff I do. I don’t have high hopes that any visual alignment approach, including computer vision detection of marks in a de-warped fisheye bed image (like Snapmarks) will ever be good enough. So, I tend to use jig techniques.

For reusable jigs, I align as best I can visually, trying to minimize rotation when I load the jig; do test prints (either on sacrificial pieces or, by doing a low-power pass on a piece covered with masking of some sort); use the precision alignment tool to adjust positioning and; repeat until it is accurate enough.

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Yes this is the backup option but with the way Glowforge handles layers and projects it becomes very tedious. If Glowforge UI didn’t force bundle overlapping objects in the project it would be easier to do the iterative solution you describe but as it stands I find myself having to create multiple projects and move layers around manually which defeats the jig approach because you no longer have guaranteed alignment. I shouldn’t have to construct my vectors in a guess-and-check manner to work-around the “smarts” of the UI.

Ultimately I think GF needs to publish a guide on how to do precision work and make the features support that use case. Snapmark was a great tactic for doing all of the above and without it the user base deserves a better solution than just guess-and-check with the current UI.

You can whine and stamp your feet as much as you want, but you bought a base-model toyota and it seems like you expect high-end supercar performance.

The machine is capable of incredibly precise cutting and engraving if you learn how to use it. Generally, that means all print operations are in the same file.

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There were a number of people who figured out how their gf was off waaaay before snapmarks were even a thing and this is exactly how they got precise placement.

Someone even told us, arrow key three to the left and down two. And that’s how they did their work from what the screen showed them.

Of course every gf is off a different way so if you figure out yours you’ll be set. It’s a pain but a quirk of the machine. “It is what it is.”

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I am not sure I am understanding exactly what you are trying to do, then. If you wanted to share details, some of us might have a better shot at tailoring suggestions.

I just finished working on a job that involved 11 separate operations on two sides of an object with a tolerance of about .3mm. After getting the jig set up and the operations for side one set, I made a copy of the job and set up side 2. So, it was repeatable without changing any settings. If you are having to move things, I would think there would be something different you could do that doesn’t involve that.

When you talk about “force bundl[ing] overlapping objects,” are you familiar with the ungroup functionality?

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When you have a precision number you can go there any time. If you have a jig precisely placed you can put the Jig there any time, If the Jig is precisely placed and the design is precisely placed It does not matter what the screen shows, that is where it will print.

Getting a number to match the jig might be a bit of pain, but once done it will never need doing again.

I remember doing this. Everyone had to do their own ‘calibration’ then figure out how many counts up or down and to one side to get precise line up. Everything now is golden compared to that, but it worked just fine at the time.

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