Problems With Magnet That Holds Lens

A day or so ago, I took my lens out with the tool to clean it and noticed that it didn’t look right. After some inspection, I realized that the magnet that holds the lens in place had pulled out along with the lens. When we’re busy, especially during the holiday season like this, I usually clean my lenses before starting for the day and this has never happened. After some struggling, I seemed to have gotten it reseated.

The problem is that it still seems “loose” which is causing focus problems with the laser. My scores are looking really wide. The kerf on the cuts seems to be wider than usual. Things aren’t wanting to cut all of the way through. I’ve checked it a few times while working today and the lens seems to have dropped down much farther than normal in the print head and I have to push it back up with the tool. Anytime I remove the lens with the tool that magnet is stuck to the top.

Has anybody ever had this happen? I’m going to limp through for the next few days because I have holiday orders stacked up, but I’m not sure how to fix it. Do I need a new magnet? A new print head?

One thing that often causes confusion is that the lens is meant to move: that’s how it focuses. There is a motor that moves it up and down (you can sometimes hear that ticking sound). You don’t have to worry about pushing it up in there. You can see to double check that it’s working normally.

Can you share a picture of what is stuck to your lens? It’s possible something has broken, but maybe folks here will recognize it from a photo.

Also double check that you haven’t put the lens in upside down. It happens and that will definitely mess up your prints.

Finally, if you haven’t already done so, reach out to Glowforge support to get a conversation with them started. It can take a while. But they also have access to diagnostic logs that none of us here do, and can often remotely determine what needs to be done.


If you put the lens in upside down this is exactly what happens.
Make sure it is ‘cup’ side up.


It the machine is under warranty, they will likely send a replacement print head. They cost several hundred $$ otherwise. It’s one of the most critical and complex components on the machine.

If you are out of warranty, there probably would be little to lose by very carefully applying a VERY small amount of CA to the ‘up’ side of the magnet, and re-installing it with the lens attached to it to help guide it into place, and using the lens tool as normal.


If I were going to do this, I would use a different adhesive like a tiny dot of E6000. CA glue may produce vapor which you would not want anywhere near optics.


I wouldn’t jump to this. Your lens will change its position based on the engraving height. When you power it on you can heat the clicking coming from the print head and it is the lens clicking through the positions.

There has not been any additional posts and so I assume you are back up and running?

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