How to get focus correct when printing on multiple objects on bed?

Thanks!

I’m sorry your prints weren’t turning out beautifully! Thank you, everyone, for all the helpful tips and tricks! Did you have a chance to run the camera recalibrator as @primal_healer mentioned? If you run the camera recalibrator and continue to have issues with alignment please let us know and we will investigate this further.

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Does having an uneven surface where one side is higher create an off center engrave?

If it is uneven. both where you think it is and where the focus height is will be off so it will not cut through, and it will not be where you expect.

@keahiskorner the autofocus can adjust the focus up and down by up to 0.5” (12.7mm). It will autofocus once at the start of your print. The print can succeed even if the surface is uneven. It can change by about 0.15” (3.8 mm) up or down and still work. That means it should engrave well in the center of your object, but if you engrave out to the edges, it may get blurry or stop marking the material.

Please let us know if you continue to run into trouble after trying the camera recalibrator.

I recently saw an older article about snapmarks and how it is unavailable now. This is exactly what what i want to help with problems I’m experiencing and what i’m trying to do. Is there a similar solution that I can do/use since Snapmarks has been removed?

If you are trying to print on multiple oddly shaped objects, the best technique is to create a jig for it.
(The Snapmarks require adjustment for varying heights as well.)

To do that, you would place several fork outlines in a design, the same size as the forks, and give them a cut line.

Then you place the engraving for the forks onto the file aligned with the cuts.

Something simple like this works extremely well:

When you bring the SVG file into the Glowforge Interface, you will cut the red lines out of a sheet of pinned down cardboard or other jig material. While you do this, set the Engrave to Ignore.

Then remove the cutout sections without moving the material on the bed, or the design image on the screen. Place the forks into the holes and close the lid.

In the thumbnail column only, change the Cuts to Ignore and set the Engrave to be processed. Set the height of the Engrave focal point (in the Manual Settings flyout) to be the mid point of the engraving area - particularly if it is curved there. That entry will over-ride the auto-focus, which probably isn’t going to land exactly where you need it to for engraving on thin fork handles, particularly with multiples on the sheet. It’s your chance to set the Focal Point correctly for the Engrave.

Then process the engrave on the forks.

It’s a bit of extra work, but you’re trying something pretty tricky with multiple curved objects on the bed. :slightly_smiling_face:

(Alternatively, you could prop up the area where you are engraving to make it more level.)

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Thanks @Jules. This is actually the best explanation I have read about jigs. I haven’t needed them yet, but I keep meaning to go back and search about the process for when it is needed in the future. I now have it firmly in my head how to accomplish this.

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Glad it’s understandable! (I’v been meaning to write up a simple example for a while…just never remember to do it.) :smile:

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Thanks for that great jig tutorial, @Jules! I hope these tips and the camera recalibrator helped out.

As for this thread, I’ve moved it to ‘Everything Else’ so discussion can continue there.

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Thanks. I was thinking about something like this but didnt know I could set setting to ignore.

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Yep! Sure enough! Makes it pretty simple to use. :slightly_smiling_face:

Jules,
Can you reuse the jig if you mark the placement to be placed in the same position everytime you want to use?

Unfortunately not without Snapmarks. That is the place where they really shine, because they give the machine a way to recognize the jig, and they can correct for the orientation of that jig if necessary.

So no, for now, if you don’t have Snapmarks installed as part of the Beta, you’ll need to recut the jig each time.

(There is one exception to that…if you do not move the original jig, but leave it pinned in place, then you can save the file by going back to the Draftboard, reopen it later and it should still be aligned. But the minute you try to cut something else and move the jig, you have to cut a new one.)

Bummer.
Thanks again.

If you make your jig in a way that it sits in the same place each time, then you can.

(Just by way of example) - a full sheet of PG can be located in the same spot every time, there are lips along the edges of the tray that you can set it against. Same with the tray itself - it moves slightly but you can slide it to the extremes forwards and to one side.

If you create your jig so that it can be located as I described, you will get accurate placement every time. You may need to use more than one piece of material - i.e. if it’s something that needs to be centered with the tray removed, you might need to cut flat pieces to place on each side and in front of the jig to align it against the front and sides.

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Something like this - two separate pieces at the front that slide up against the front and sides, with a cutout to locate the main jig piece in the middle:

This would work with or without the crumb tray.

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If you do that you also have to lock the tray down. Just pushing it to one side doesn’t always work out, although you might get close enough for government work. :wink:

These boots are made for lockin’…

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The first use I found for those 4" tiles folks have been engraving is to create perfectly parallel specific locations on the crumb tray that can be used to put your jigs or in my case all that 3" wide wood I foolishly bought thinking I could get 3" wide work out of it. This is done by working off the front chastity plate that if the door is closed tightly is always in the exact same place, and even not is at least always parallel to the movement of the laser.

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