Hello together,

I just started with an eggbot. How could I achieve that the text and ornaments are not distorted when I print them to the egg? Is there any tutorial for it?

The dimension is 3200 x 800 px

Thank you very much for your help

Goof

That must be an ostrich egg, or some kind of other material made in an egg shape!

Aren't there tutuorials on the website that sells the machine and/or the site where you can download the extensions? I thought there was, but I don't have that link saved anywhere. If not, the Evil Mad Scientist website probably has some (or IS that the site that sells them....??)

Or, didn't the machine come with instructions?

The question that you are asking is equivalent to asking "how do I make a flat map of the earth where all of the continents are the correct shapes -- like they are on a globe -- without distortion?" Or equivalently, how can you take a flat map of the earth, and wrap it around a globe? And the answer is (in essence) that you cannot actually do this without some kind of distortion.

This is a long-standing, well-known problem called map projection. The wikipedia page has this to say:

The mathematics of projection do not permit any particular map projection to be "best" for everything. Something will always get distorted. Therefore, a diversity of projections exists to service the many uses of maps and their vast range of scales.

This should make sense to you if you think about it for a moment: If you try and take a flat map of the earth and wrap it around a globe, you'll find that it wraps smoothly around the equator, but things get challenging around the poles. To make it fit, you would have to aggressively crumple the paper near the north pole and around Antarctica. No matter what kind of flat map you use, it will never map perfectly smoothly-- and that is simply because it is flat, not curved. This is the same reason that (for example) Greenland looks huge on certain projections.

The EggBot uses the Equirectangular projection, which is to say that the distance on your template is mapped directly to the angle that the pen will be positioned at. The 3200 pixels of the template's width form a one-to-one map to the 360 degrees of the equator of the object that you put in the EggBot. The approximately 800 pixel vertical height of the template corresponds to (800/3200)*360 = 90 degrees of vertical travel. You will find that as with wrapping a regular map onto a globe, distortion is minimal near the equator, and larger near the poles.

You can read more about the EggBot coordinate system here.

The EggBot Quality Troubleshooting Page has some additional hints about distortion on the EggBot, and on compensating for the shapes of eggs versus spheres (a separate topic!).

The EggBot Stretch extension for Inkscape will pre-distort your drawing to partially correct for the distortion of a drawing wrapped around a sphere when viewed from a particular direction.

Thank you very much for your help. That helps me a lot. I give it a try.