I just had my first Proofgrade medium Maple Plywood failed cut this morning. Five objects to cut, on all five the outside cuts went through, on two the inside cuts didn’t go all the way through. My sheet of plywood had a slight bow to it though, so that’s what I’m chalking it up to. What I can say is that the issue isn’t universal. Sorry to hear about this though.
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I had this happen. I must have touched the lens on the head. I used one of the wipes to clean it, and now it cuts fine again
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I wish it was that easy. I cleaned the lens after the first attempt.
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Thanks for posting about this. I’m so sorry you had trouble with your print. Let’s get you back on track.
Would you try a few things and answer a few questions for us before we dive deeper into investigating?
- Have you successfully printed on Proofgrade™ Medium Maple Plywood using Proofgrade settings before? If so, when (if you can remember)?
- Would you print a Founder’s Ruler on the same piece of Proofgrade Medium Maple Plywood using default settings and let us know how it goes?
- Would you do another small test print using one of our designs on another type of Proofgrade material using Proofgrade settings and let us know how it goes?
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I had the same thing happen once with the same material. Next day I did a quick cut on the exact same sheet, and it cut no problem. No clue why it didn’t cut completely through the day before.
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I’ve noticed that cutting tight complex curves usually results in more incomplete cuts than nice geometric shapes, so i usually just adjust for it up front by slowing down the normal cutting speeds by about 10 to 15 points, especially if I’ve got a design with a lot of curves and switchbacks. 
(Or I’ll send it to cut a second time without moving the material afterwards if I forgot to adjust for the curves up front.)
Sometimes it helps to cut weeding lines too, to keep from breaking a tight fitting thin shape.
YMMV. 
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That’s odd because it would need to go slower around tight curves and that normally causes over burn. That is unless they have started to compensate and are dropping the power too much.
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Have you successfully printed on Proofgrade™ Medium Maple Plywood using Proofgrade settings before? If so, when (if you can remember)?
Yes, many times. Probably a week prior to this incident? Not sure for that material specifically…
Would you print a Founder’s Ruler on the same piece of Proofgrade Medium Maple Plywood using default settings and let us know how it goes?
Sure, I’ll knock this out when I get home tonight.
Would you do another small test print using one of our designs on another type of Proofgrade material using Proofgrade settings and let us know how it goes?
Sure, which design would you like me to use? I’ll throw it on some draftboard.
Would you print the Straight Shot Cable Ties?
Also, did you clean the windows as well as the lens after the first print didn’t cut through? Pictures of the windows are available in the cleaning instructions.
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This is the first piece of real printing advice I can find. I have had failed cuts on plywood AND draftboard and all the support team can tell me to do is clean my machine. My machine has been cleaned and recleaned! Super frustrating, but thanks Jules for the tip on slowing down cutting speeds. Strange though - seems to me the proofgrade settings should “cut like butter” on a simple design! I tend to just set it to do 2 passes every time now, which seems like a waste of time to me as the proofgrade settings SHOULD work, right?!
They should. Consistent failures on PG across multiple PG materials and projects with a clean machine and flat material should be addressed by Support. That would seem to be a machine issue.
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In a perfect world, it would.
But there are an awful lot of variables with this, and it can be caused by anything from a dirty lens (it really is one of the top culprits 
) to a slight amount of warp in the material, or a bad spot or knot in the wood. So the folks at support have to be kind of general with the suggestions to make sure that everything has been checked and eliminated.
What I always check for if I get incomplete cuts is:
- Is there even a tiny amount of warp in the wood?
Using the Honeycomb Pins has been a lifesaver for me because the wood down here always warps. (High humidity area here.)
I keep a little spice jar of them next to the machine and use them up front…no more problems with incomplete cuts.
If there is one side of the bed that consistently doesn’t cut through, but the rest is cutting okay, that’s a sign of a slight warp in the material. It doesn’t take much to cause an incomplete cut.
- The lens needs to be cleaned using the instructions here:
https://glowforge.com/support/topic/cleaning-service-and-moving/cleaning
That needs to happen more frequently depending on what you are using the machine for - engraving on things like draftboard and plywood throw up more resinous gunk than etching slate, and cutting throws up more gunk than engraving. When the tube starts to look a little yellow, i usually clean the interior, but it’s usually only every few weeks.
- The part that I mentioned above about adjusting the speed for the design is not something that Glowforge can suggest, since they don’t know what kinds of designs we’re trying to cut. And that comes from personal experience after years of designing digital cutter files - we had to make special allowances for tight curves and corners in those, due to the limitations of the machine movement. It translates very well into laser work as well.
Once you know it though, it’s a lot easier to modify your settings slightly and you’ll get even fewer bad jobs.
Having done those three things, if you still have trouble cutting through the Proofgrade consistently, it might be a focal issue or a power issue on the machine, and you would need to open a support ticket on it. (I’m not talking about just a little tab or two not cutting through, I’m talking about it’s not making it all the way through on any cuts.)
As you get a little more comfortable with the materials, it will happen less and less. I can’t remember the last time I had an incomplete cut on anything. 
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Yes it should cut through the PG every time if all surfaces are clean, lens and mirror installed correctly, the material is extremely flat and the material focal scan is taken on the design to be cut.
But Support has to hold everyone’s hand first. There is no way to differentiate between the experienced and the newbie. Even the experienced can be quite illogical and skip steps. For example have seen a bunch of too smart folks not read the instructions and didn’t know there was a laser window to clean on the far left side of the machine. Many more people think that flat is just eyeball flat which is not good enough.
Have seen a problem where the material thickness scan occurred in a previous cutout or a significant distance from the parts to be cut out. If the material is not held down where the scan is taken a large focal error could occur. That’s usually only a problem with multi-part designs.
Your machine may have real problems but Support still needs to rule the simple stuff out since poor cut performance has been most often not the machine.
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Totally get it. I guess I am just one who follows directions meticulously and have been getting frustrated with the same response. But I appreciate your guys help and comments! One thing I haven’t done is utilize the forum enough. I just really didn’t think there would be any scenarios were I would have to adjust PG settings on PG materials. Learn something new every day 
Thanks Jules! Definitely going to try those Honeycomb pins!
I clean my lens regularly - probably more than recommended right now with all the errors I have had. And even still, sometimes after I clean it and do only 3 short prints, my GF seems to have trouble focusing or recognizing the PG material I am using…?
Definitely a learning process even with the PG - and I am realizing I need to utilize the forum more! =)
Glare on the stickers is more responsible for misreads of the stickers than anything else I think. Eventually they’re supposed to go an invisible UV printed code all over the masking that should do away with that.
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You shouldn’t - if you’ve done everything support asks and it still doesn’t work, please do file a new ticket (by emailing support). We’ll move on to other troubleshooting steps, up to and including replacing the machine if needed. It’s rare, because most of the time it’s something easy to fix, but sometimes it’s necessary.
Note, by the way, that Support tracks all new threads in this category, but does not get notified when someone replies to an old thread, as happened here. Lucky I happened to see it. 
One other reason we double check the easy stuff: if we get the machine back and it was a dirty lens or warped material, then we have to charge you for roundtrip shipping - which stinks. So we want you to be sure before you send it!
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Thanks, Dan! Most of the time their recommendations work, but only temporarily. I am cutting some honeycomb pins as we speak to see if that doesn’t help with more consistent cuts! (and cutting all the way through without having to do 2 passes as that’s what I am doing on all PG cuts right now) Fingers crossed!
Other than the overhead lens/camera, should I be cleaning other ones more often to help with focus?
Camera is a fixed focus so the preview view clarity only relies on the one camera lens.
So here’s the question: which lenses and windows have you been cleaning per the instructions?
That statement makes me think you’ve only been cleaning the lid camera, which won’t affect cutting performance either way. It will help the system calibrate, give you a clearer view of the bed image in the app, and recognize QR codes better.
The laser is for all intents and purposes invisible but it’s taking a fairly long path before it shoots out of the head at the material.
There is a window hidden on the left side of the gantry, underneath the machine top (have to poke head in to see pretty much), a window on the left side of the head, then a mirror inside the head (beneath a removable top), and finally the lens on the bottom side of the head that has to be removed (with the lens removal tool) to be cleaned.
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