Depth Sensor misses Material


#1

Wasn’t fast enough with the camera to get a shot of it happening… but I just started to do a coin on some scrap material. LOADS of void spaces.

I hit Print, and it goes to “Scanning your material” mode. I happen to walk over and look at the machine while this is happening, and the big red laser dot for scanning my material height is pointing right through a void, WELL away from my actual pending job location.

So, if it did sense the depth, it just picked up a 0.00" or even negative on that one…

Could scanning material maybe happen ON our planned engrave/cut paths somewhere? Or give us a widget to move around which will control where it will scan material (This would be very useful when working with irregular thickness things like rocks and found wood)

EDIT: Okay, coin finished cutting, and apparently the sensor DID sense in the middle of where it decided to cut the job. Which was not where I placed it at all. So, random odd sound I remember hearing had been a mis-alignment happening.

So… different bug report, my head mis-aligned itself. But I haven’t investigated how/why yet.


#2

Perhaps a trick-cyclist might be able to help ?

:upside_down_face:


#3

Interesting. I look forward to knowing the cause/resolution.

I recall once having the depth sensor pick a seemingly-arbitrary spot on the bed, completely missing my material. But in my case it still engraved the job properly. Since then I haven’t payed it any attention.


#4

What was the sound like?


#5

Oh, I missed that part! I had a weird sound when mine misaligned last week! Not sure if yours was a similar sound. Mine sounded like the head hit something. It didn’t. And couldn’t. But it sounded like it did. Wasn’t particularly loud. I wasn’t even completely sure I heard something. But since it coincided with a huge misalignment (>.5") I figured I actually did hear something. It did it like 3 times, where it sounded like the head hit something on the right side. Again, it didn’t, but that’s the best description I can give you for the sound.


#6

As you discovered, the laser head checks the material height at the location you are planning to print on. I’ll pass on your request for the ability to choose where it will scan.

We have a few questions to help us better understand what happened

  1. What was your Glowforge doing when the sound occurred? For example, was it printing, calibrating, scanning your material?
  2. Do you know approximately when the sound occurred?

If you are still seeing mis-alignment, would you please do the following:

  1. Turn your Glowforge unit off and back on, then wait for it to calibrate
  2. Print a simple design, like your coin, and let us know if it prints where you expect it to (keeping in mind that we’re still improving our layout and alignment, so your print may appear offset from where you put it by up to a quarter inch.)

Thank you!


#7

Been a string of late nights, and my memory is poor at the best of times. So unfortunately me reporting anything is unreliable at this stage.

Pretty sure the sound had been during the move to sense the material, and that hearing the sound is WHY I went over to look at the sensing, when normally I would not bother to do so.

The sound was the same as the initial calibration sounds when I first turned on the machine. Steppers clicking because they are pushing the head against a physical limit. But in this case it would have been moving from the upper left corner to the sensing location (about mid-bed), and should not have hit any obstructions.

I corrected my post with the edit when upon re-positioning the material, getting a new bed scan, moving my job to a clean piece of the scrap, and hitting Print… the machine re-calibrated itself (first time it ever declared a need to recalibrate and actually DID do so successfully. Normally that is a point where things freeze and I have to reboot).

The second attempt printed where I expected it to (with offset, but the expected offset).

I will be sure to make note of any future sounds like what I had heard, and to investigate immediately on any misalignment. For this one, I cannot even speculate on possibilities, because I am unaware of any chance of having had something on the rails or any other possible cause.


#8

When it missed the material with the laser could you tell if it was off in X or Y?


#9

Mostly X (the 20 inch span), hard to say if it was off in the Y or not, as that didn’t get clipped. But in the X half of the coin was missing, when it should have been completely formed with a bit of material to spare before the void (aka - about a one inch shift)


#10

I’m glad to hear that you are printing again and I appreciate the details. If the problem reoccurs, please post a new topic.


#11