Laser Power

I’m looking for some help with my Glowforge Pro unit. The laser is not cutting all the way through the proof grade materials at the proof grade settings. Before you respond, please note:
I have already gone through a thorough cleaning in accordance with the manual guidelines.
I am using flat material and it is sitting flush to the cut bed.
I have run sample cuts for log purposes.
In short, I have scoured the forum for all previous suggestions, and followed them… no success.
Okay then, let the new suggestions flow!!

Support will need pictures of the results of printing the “Gift of Good Measure” on the spare medium draftboard they provided. Based on that, will provide further guidance. It’s likely the machine will have to be sent in for repair.

I’m fairly certain that you are correct in how this will play out. This was kinda my “last ditch effort” before that happens.

Yeah, it’s unfortunate. There are virtually no moving parts that control the laser power, only the optics that can impact/degrade it.

The only exception is the focus lens, which is controlled thru the grey ribbon cable attached to the head. If your prints are still sharp (hence needing to print a known design on known material), there’s no issue there.

It’s likely a power supply or laser tube issue.

There’s another potential issue–I know because I’ve done it :stuck_out_tongue_winking_eye:, and nearly did it again last time I cleaned my lens–installing the lens back in upside down. This dramatically reduces the effective power, and is worth double checking before blaming the hard ware!


Have you tried adjusting the focus height manually (FH)?

I say that because I had problems with not cutting all the way through and adjusted the FH by one tenth of a mm. (5.4mm instead of 5.3mm).

In my case Regular cleaning would not limit or solve the problem, hence adjusting the FH. After that, I have clean through cuts and it was obvious that FH was the problem.

I think that adjusting FH limits the effect of material warping.

Adjusting FH will create a focus point of the laser beam just under the material instead of just above the lower edge of the material, thus more likely to cut through. I hope this helps.

That’s not actually how the focal height works, but I don’t want to derail the OP’s support ticket. There are plenty of discussions on the topic elsewhere on the forum.

Okay, I will look into the topic discussions on this forum. My explanation could be wrong but adjusting Focus Height was 100% good result in my case, that’s all.

Maybe I should have put emphasis on increasing the FH by a fraction thus in effect moving the Focal Point from the top the material closer to the bed. Is that better said?

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Manual focus heights only work when the focal height field is different than the material height field. For example, material height of .240” and focal height of .228”. If material height and focal height are the same value then it uses the autofocus measurement taken during the scan before the job.

I believe you’re actually moving away from the bed when you increase focal height.

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Your posts are not helping the owner here. A correctly operating machine does not need adjusted focus height to cut thru proofgrade materials.

If yours does, then there is something wrong that needs to be addressed (unless you choose to live with it). Feel free to start your own thread to discuss this.

I stand corrected.

You could have PM me your opinion instead of high jacking this post. The owner is even asking for suggestions! I wasn’t aware you are working with the post police.

It’s clearly not a correctly working machine. You suggested it might need to be sent back, very help full indeed.

I only said what works for me. Clearly my work around doesn’t make sense to you but other’s might see the benefit in my solution. For the record: I don’t use it for every PG cut but certainly for non PG

I leave you in peace

I’m so sorry you’re having trouble cutting through your materials! Thank you for doing that initial troubleshooting. I would like to check over just a few more things. Could you do the following for me?

Please take photos of all your cleaned optical components, with special attention to any damage you might find:

  • Both windows
    • The printer head window, on the left hand side of the printer head
    • The laser window on the inside left of the Glowforge
  • The printer head lens
    • Both sides of the lens, top and bottom
  • The mirror inside the printer head
  • The bottom of the printer head

Could you please also include a photo of the front and back of one of the prints that didn’t cut through?
Please also let me know the date and time of the print (including time zone) in your reply. You can either post the photos here, or you can send them to if you’d prefer.

After going through all of the suggested cleaning steps for documentation, a very close inspection showed “burning” or a dark spot in the center/backside of the lens. I’d call it more of a discoloration than anything. There was debris in this location a while ago, but had been removed and cleaned. I didn’t notice the burn mark then. A swap out to a new lens has corrected the situation.


I’m glad you resolved it! I’m going to close this thread. If you run into any other trouble, please start a new topic, or email us at We’re here to help!