Real World Example of image placement results

accuracy

#1

I’m not putting this in a topic about the bed, the X,Y or the homing zero positions topics.

I’m putting this here as a start to the investigation of how the Glowforge operates and not how we wish it to operate. I’m pretty sure those two ends will coincide.

Screen captures and other images to follow.

Please disregard portrait video. I need to remember that when leaning over things and shooting video, I have to check orientation.

Lesson learned.

Ok, another lesson learned is to figure out the size of video I can post. I cut it down, but still too much. Don’t want to mess with much editing. YouTube it goes.

Here are closeups of the left and right side. I’d guess the right side is last tick is 3/1000ths away from the edge. I might have placed it closer if I tried. I have a digital calipers and checked the gap. About the thickness of Quill premier series yellow legal pad paper. That’s over six inches.


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#2

The evil laugh is the best!


#3

The evile laugh definitely makes it. lol…

One thing I’m curious about, though… how is the Glowforge handling the “Glowforge Founder” and other text? Is it lasing them as the vector fonts, or is it rasterizing the text and other artwork? Given the lack of serrations on the digits, I’m assuming vector movements?


#4

I would upload a video of it here, but there is a limit of size. Need to go upstairs and change my firewall settings so I can ssh from my Windows computer downstairs to access the great Linux software that can convert video to gif. Just uses command line which is great.

It rastered the text. It looks like it is vectored because it is deep and precise.

For the luggage tag, I overlayed a jpeg of the address that I had typed out and it recognized as a raster. There is an interesting work flow thing that you begin a custom design by uploading either a vector or raster image. Once you get to the layout screen, I don’t see a way to upload another vector file. Will pursue.


#5

Very nice work!


#6

The ruler is nice, but all of the lines look a little wavy to me?


#7

Yes, that is clear. Check out this compare and contrast with horizontal placement of ruler versus vertical.

This unit and its capabilities is not all the way dialed in. Will do some more tests regarding the lines.


#8

Just seeing items made of natural wood makes me drool :sob: and envy the work you are doing.


#9

Looking at the waviness of the lines closely looks like about 1/10 of a 1/16th inch for the raster cut where the head moves back and forth 6" and burns a spot segment of the line each pass. Better than my eyes will notice without magnification though not yet up to specs. (~0.007"?) I have no doubt that if it were a vector cut instead of raster the lines would be far more precise. It’s getting there.


#10

Is some of the waviness perhaps due to the grain of the wood? It would be interesting to see an acrylic one.


#11

Some is the grain. Some not. Wow. Have we shared a mind meld?

Check out what I posted here just now.


#12

Is this FFmpeg program or something different? ffmpeg is something great but I’m not all so crazy about the command line so I’m probably underutilizing it…though it is fast!


#13
  1. The shifting could be due to you using a rolling cart and not securing your material/cart. The momentum of the head can cause everything to rock, especially if its at the right frequency and constant (which raster engraves tend to be).

  2. A good test of image placement accuracy is to engrave a ruler. Take everything out. Put it back in the bed wherever and attempt to engrave again EXACTLY on top of the previous engraving and see how far off it is.


#14

Thanks so much.

I hadn’t thought about point about the rolling cart. It is on carpet so it doesn’t roll, yes. I can push the corner of the cart and it wobbles slightly on the casters at the horizontal hub since the casters themselves aren’t solid. I will investigate a solution for stiffening up the cart, including removing the wheels. Or I could put it on the pool table, that’s solid! Not long enough hose though.

The print head does have some heft to it and the momentum could definitely shift the whole cart.

And engraving over the same piece. I will test that.


#15

Sweeeeet. Don’t use good stock though. Use some trash stock or MDF if you have it. That way the grain won’t get in the way of detail


#16

I think that if you put a Newton Cradle on top, it could be most amusing… :smiley:


#17

Oh yeah, try to NOT put in directly under the camera, put it horizontally and vertically offset from the center a bit.


#18

I’ve faced a similar problem with a 3d printer on a cart. Pipe insulation foam on the legs and then butting it hard up against a wall or solid object will help at least a little. It’s the X axis that will be the problem.


#19

Have you ever played Santa? Your contagious chuckle during the video was perfect…I didn’t think it sounded evil at all!


#20

X will be light with high acceleration and has one motor. Y is very heavy with slow acceleration and two motors. So the force when Y changes direction could be up to twice that when X changes direction. That being said resonances come into play when things shake so it can just depend on frequency.