Off-centre for laser engraving


#1

I’ve had the GF Pro (UK) for about 3 months now and do mostly laser engraving. However, I’ve noticed that I have to off-set my image slightly to the left when aligning with my item on the screen to make sure that it actually centres it when engraving. I’ve checked and cleaned and no changes. Anyone else experiencing this/is there a solution/should I let support know?
Thanks in advance.


#2

If by offsetting you mean that there is an alignment error of 1/4" or less at the edges and usually much better toward the center, then yes that’s normal. The lid camera does not give perfect alignment and is often only good for getting it close. Hopefully, someday they will start using the head camera for precision alignment or improve the lid image accuracy through other techniques. TBD.

Cleaning the lens, windows and camera does not change the image alignment. Cleaning is necessary for other functions and is very important to keep the parts from deteriorating under stresses of the laser beam.


#3

Like @rpegg said, it’s currently normal to experience an offset of up to 1/4" in visual alignment using the lid camera.

You can use a jig to align your engraving relative to a cut and get perfect placement, and perfect alignment, and that is what most of us are doing now if we need to engrave on something that isn’t cut out of the material at the same time.

Couple of tutorials here:


#4

So, I noticed the same thing … but it isn’t an issue to me 'cause I’m not a perfectionist. Every project I’ve worked on is ‘just a learning exercise’. But recently I took a look at me very sturdy, old desk upon which PhantomForge rests and I realized that the garage floor slopes every so slightly to the center drain. Which prompted me to set a level on the top surface --> and I had an aha moment. About a 1/4" fall laterally which I surmise might have an affect on the gravitational forces of the laser firing (making this up to sound as technical as many others). So I searched for some small flat board to shim the low side (and where do you think I found such a piece(s) – yup my scrap materials storage container).

Made another engrave on a tile — and, methinks it was better.

More to follow. :sunglasses::glowforge:


#5

Level won’t matter too much, but having the surface dead flat is fairly important. The reason is that the case of the unit can twist with the slightest unevenness. Most desks, tables, etc are not flat. A lot of folks will place shims under the runners to make the case more true. Usually an uneven surface will make the front corners of the lid to not sit flush with the slides (BTW: the center sides of the lid glass show a bulge on all the units. You can ignore that.)


#6

@tracey_grundy

Thanks for letting us know about this.

The software on your Glowforge is responsible for ensuring that the print lands on the material in the same place as the preview. When you’re done with a print, let a new image load. If the print appears on screen far from where it was supposed to go, you may have an alignment problem.

Most alignment problems come from the material being closer or farther from the camera than expected. While the software is still improving, you can take these steps for the most accurate alignment results:

  • Use Proofgrade™ materials.
  • If you don’t use Proofgrade materials, use a precision set of calipers to measure your material, and enter the thickness in the “uncertified materials” dialog.
  • Use material that is not warped or tilted.
  • Place your design near the center of the bed.
  • Clean the area underneath your crumb tray, particularly the four indentations on the floor.
  • Reboot the machine. Alignment can drift over time, particularly if you bump the head of your Glowforge while removing material.

I’m going to close this topic. Should you finish all of these steps, and find that you have an alignment error of more than 1/4", please contact us, either by posting a new topic or emailing us at support@glowforge.com, so we can investigate.

@bmcgrain

So, I noticed the same thing …

We try to keep to one topic per post in the Problems and Support section. If the trouble persists, can you please create a new post with this question?


#7