Artwork size not matching Scanned material size

[tifire22]

Good morning! I am trying to engrave a piece that is 1 3/4” x 1 3/4” x 7”. I made my artwork to be 1.25” x 6.5”, and made a “guide” square that is 1.75” x 7” to for alignment. I have the guide box set to ignore. But when I do my scan, it is showing the piece about 0.5” shorter than my artwork. I made sure to measure everything again and check all my numbers. I checked the focal height as well and made sure to focus the machine directly over the piece I am trying to engrave. Any advice to get them to match up?

[deirdrebeth]

Welcome to the community, we’ll get you sorted

Which machine, and how thick is your piece?

If it’s taller than just under .5” you’ll need to remove the crumb tray and raise it so it’s within the focal distance.

[dklgood]

I think a picture would really help us identify the problem. Can you share a screenshot of your project?

[tifire22]

I have a glowforge pro and the crum tray is removed. Here is an image.

[eflyguy]

The camera is spec’d to 1/4", so that much out on each end is within spec.

It is not a precision alignment tool. If you need precision, use a jig.

[tifire22]

Do you have an example of how to approach that?

[evansd2]

You’ll find the answers in my FAQ. Check out #15 and #23:

Common problems/questions

Hello! You’ve been referred to this post because you have a common problem or question. Check out the list below to see what this post can do for you. Just click on a topic that interests you. • 1: I’m new to Glowforge and really have no idea where to start • 1a: What other tools/materials should I buy to go with my Glowforge? • 1b: What are the overall best practices for my laser designs? • 2: All about masking/protecting your materials • 3: I want to design/make a box • 4: What materi…

23 goes deep into jig techniques.

[tifire22]

Perfect! Thank you for this information!

[deirdrebeth]

All the jig information is useful, but while you didn’t say, with that much curvature showing I’ll almost guarantee your working surface is lower than it has to be for the laser to focus on it properly. You might try making yourself one of these in order to get your heights correct and your work doesn’t finish out of focus!

No-Math Focus Ruler

Leveraging the recently-released Set Focus tool, I’ve designed a tool to help place materials when the crumb tray has been removed, no maths required. If your material is between the lines while resting on the bottom of your GF – not the crumb tray, you should be able to use Set Focus in the UI. If the top of your material is below the bottom line, use your favorite method (sheets of PG, tiles, 3-D printed stands, matching sets of trained hedgies, etc.) to elevate it and recheck. Repeat until …

[eflyguy]

The piece has no curve, and he stated it’s 1.75" square so it’s perfect with the tray removed.

What you’re interpreting as “curvature” is the reflection of the lid LED’s on the metallic panels attached to the floor of the machine, which is ~1.5" lower than the camera is meant to work with. All machines show this when the crumb tray is removed.

[deirdrebeth]

Yet most machines are far FAR closer to exact than they are the .25” “acceptable” standard. If that’s truly as off as the machine is I’d suggest running the camera calibration before using a jig. If that piece is supposed to be 1.75 but is actually 1.5…