What kind of machine would be best suited to engrave a photograph (grayscale) on a glass sphere?

I have checked out the eggbot, and openbuilds "spherebots"....but neither of these options can do something like a photograph.
Would I need a 5-axis machine? If so what type? I know nothing about them. What types of cnc machines out there could achieve this?


1 Answer 1


Laser cutters like this Epilog can engrave grayscale images as well as glass and curved surfaces. See some sample images below. But I am not sure how much grayscale you will be able to achieve on glass. You might need to achieve this effect with halftone.

You will need an added rotary attachment for curved surfaces. This will limit the size of work piece you can use. The laser with rotary attachment is really only suited for cylindrical objects, not spheres. As the sphere surface curves away, the laser will de-focus and loose power and resolution. Fixing a sphere in the rotary attachment will also be a challenge.

That being said, I have engraved logos on pumpkins in the past with reasonable results.

image engraving

glass engraving

  • $\begingroup$ Thanks for the response. I'm thinking afterall it still might be easiest to go with the eggbot + engraver, since it can already do spheres and thats half the battle. I'm thinking maybe switching the stepper motors to achieve a higher resolution, like microstepping. Not sure how to calculate what type of motor I would need to achieve at least a somewhat-ok looking photograph. This is a first for me. $\endgroup$ Commented Nov 10, 2020 at 18:25
  • $\begingroup$ The faq egg-bot.com/faq says 3200 steps or 600dpi.....im not sure why photos can't be done then....that seems like a high enough resolution...hmm. $\endgroup$ Commented Nov 10, 2020 at 18:58
  • $\begingroup$ the image resolution is dependent on the size of the engraving bit $\endgroup$
    – jsotola
    Commented Nov 11, 2020 at 0:01
  • $\begingroup$ Not how many steps can be made? Ok, if I wanted to create the highest resolution possible...what would I aim for? Does it depend on the software too, I think its done in vectors and not raster. Engraver: shop.evilmadscientist.com/productsmenu/764 $\endgroup$ Commented Nov 11, 2020 at 1:26

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