Compact Filter, Set Focus, and Extreme Temperature Sensing: 4/29/19 Latest Improvements

I hadn’t even made the leap to that - but you are correct! That will be a HUGE bonus.

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The laser head does not measure the thickness, only the distance from the head to the top of the material where the head is.


This is also amazing!! These little updates are like candy to me.

The set Focus it’s going to be amazing though. Being able to just throw materials in the bed without the tray and have the machine do the calculations, amazing!


Still need the top of the material to be in the 1/2" range above where the tray would have been. Otherwise you will get an error.


Oh definitely. But this still simplifies it.

Thanks for the latest improvements …
Would it be possible to have a shortcut for the focus on the main toolbar, just to save time going into the setting “gear icon” and then selecting, in the same vain as snapmarks.

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Set Focus really does change everything. I didn’t measure it, so I’m not going to quote numbers on accuracy, but I feel like I’m now getting my money’s worth on using the camera to position things.

I used to worry about what I perceived as a slow release cycle on the software front, but with things like Snapmarks and Set Focus, clearly something has accelerated. I’m looking forward to the next shipment of unicorn tears!


I believe it very important that new users take the time to understand what is happening with Set Focus before attempting to use it. Not everything is obvious and the potential is there to ruin a lot of material.

Set Focus measures the head to material distance at a specific spot you select. If does not improve the overall lid camera calibration at this time, but does remove any image/design position errors due to warped material or otherwise uneven material. (At least near the point you have selected.) It also uses this measurement to change the laser focal point. What this means is that you can drop a piece of material in the Glowforge, select Set Focus near the center of your design, and after the new image scan is displayed you can be assured that the lid image for the chosen spot will be properly adjusted for any material height irregularities. You might need to tweak the design placement for the new dewarped image. The Set Focus will only adjust for material height near the point you have selected. Keep in mind that if the material height varies across a large area the Set Focus lid image will only be valid at the chosen spot.

Bottom line: Set Focus is great for small design placement but for larger designs on non-flat material it won’t help much. Set Focus measures a single spot.

Other information: The Set Focus does not actually populate the manual Material Height or manual Focus entries. When you open the lid to remove material the one time Set Focus values are lost. For example. If you had entered a material height of 0.1” for a previous engrave and then dropped in material of 0.25” without using Set Focus the dewarped lid image will of course be wildly off. After using the Set Focus tool on the 0.25” material the lid image will be adjusted. If you then scored a circle the design and scoring should overlay on the 0.25” material. (Depending on your machine’s overall calibration) But once you open the lid the unit will revert back to a dewarped image for the original 0.1” entry. The lid image will again be far off.

The Set Focus does not override a manually entered focus. However if you have not entered a manual focus the Set Focus measurement will also be used for focus. Remember that Material Height and manual Focus are two different things. Set Focus will determine both if you have not entered a value. It will always override the Material Height entry for the one time print but will never override a manually entered Focus.

It’s important to understand what is happening and why to avoid unnecessary P&S posts.


True indeed. but the material ‘height’ could then be inferred, one would think, based on the 0 point being the crumb tray… anyway, COOL feature!

OK… question to the group… and Dan. (And yes, in a prior life, I enjoyed trying the “break things” in various system test environments…)

What happens if someone tries to use “Set Focus” on something with the crumb tray removed, and the height is LOWER than the crumb tray would have been (In other words, with a “negative” height.)?

You will get an error with a negative value or a measurement larger than 0.5". Same as if the entry was manual.

The red spot measurement used by the head is only calibrated for the 0.0" to 0.5" material range.

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I was just curious what will happen with Set Focus’ “AUTO” setting in that case, and was hoping that it didn’t throw an internal error that caused bigger issues.

Basically, this is replacing the auto-focus step that runs at the beginning of the job (if you use the set focus tool, it will actually skip the auto focus step when the job runs), and in addition to replacing that step, is updating the camera image as if one put a material height in place.


Understood, but (and I know I could take my crumb tray out and try it) does it give an error if the Set Focus result is something less than 0? I’m curious how the internals handle it (since I realize that you can’t manually enter a negative value).

Yeah, I tried it without the tray and material height lower than 1.4". With a material about 1" high I got the normal “material too low or too high” error immediately after the scan. At about 1.25" high I received a different fatal error only after hitting the Print button. Can’t remember what it said but it would not let me print. Raised the material to 1.5" and it printed fine.

With the material at the 1" mark the red spot was way off to the left. I would bet that the head camera couldn’t even see the spot.


Good to know that they have at least planned for some degree of error handling for it. My past experience with (non-Glowforge) projects has taught me that to never underestimate the ingenunity of the end user.

Whatever you didn’t plan for / design for / code for will likely be found in the first three days of real-world usage. :wink:

My entire career was as a test engineer. Finding ways to test things that people didn’t think of was what I did. I also wrote a lot of the code used for testing. Interesting that the more I was involved in the initial design or development the easier it was for operators to break my code that I didn’t think of.


Thanks for the suggestion - put it in the hopper! I’m delighted you’re finding it so useful.

Agree 100%. Part of our learning from shipping this feature is how it gets used by all of you so we can improve it!

Unfortunately the margin of error here is big - between material warp, crumbs in the way, machines that aren’t flat, and so on, you could wind up with measurements that are comically wrong. We decided it wasn’t accurate enough to be useful.


“(much higher than temperatures you would ever find in a weather forecast)”

ON FIRE people. This tells you if your machine is ON FIRE!



I think at this point it just tells Glowforge that your machine is on fire. Obviously we weren’t watching. Of course Glowforge would then call the Life Alert folks. You know, the company that says “Help, I’ve fallen and can’t get up!” The phone call will go to a non-English speaking country, address will become corrupted, and 2 hours later a single fire trainee will show up at your door to see if the alarm was false.

Edit: For the company folks who don’t have a sense of humor (the lawyers), we fully understand that shutting the unit down with an overtemp reduces the chance of a full blown fire.