Parametric Oloid

I wanted to try my hand at generating an oloid using OpenSCAD that is easy to print. So after generating it, I split it into two parts that can be perfectly aligned for gluing using two pins that are made from small pieces of 1.75mm filament. I also included the ability to generate a non-pinned whole model so you can visualize the assembled oloid, or mess with it in Blender.

Recommended Print Settings

• Well tuned printers should use: artcfox-oloid-0.1-tol.stl
• 0.1mm layer height
• 0.1mm first layer height
• 3 perimeters
• 15% gyroid infill
• Optionally use a Helper disc in the center, or use a brim to prevent the tall thin edges near the center from lifting off the bed

I found that the edges near the center tended to lift off the print bed due to the geometry of the model, so I would recommend printing with a brim or using a helper disc in the center to keep those edges stuck to the bed.

Being Overly Pedantic with the Helper Disc

Here is what the bottom view looks like with elephant's foot compensation enabled (the default) and no helper disc:

And here is what the bottom view looks like with elephant's foot compensation and a helper disc 0.1mm tall added:

See how it's distorting all 3 perimeters of the model bordering the helper disc?

I didn't like that, what I really wanted was the model to be generated like normal in the first screenshot with proper elephant's foot compensation all around, and the helper disc to be drawn the way it is in the second screenshot.

My Solution

1. Turn off elephant's foot compensation
2. Add the helper disc as a sub-part
3. Move the helper disc to X: 0, Y: 0
4. Unlock its size, resize only Z to 0.1mm
5. Drag the helper disc up in the list so it's the first sub-part
6. Slice and Export G-code as helper-disc.gcode
7. Delete the helper disc
8. Turn back on elephant's foot compensation
9. Slice and Export G-code as elephants-foot.gcode
10. Use File > G-code Preview to find the lines of code that generate the helper disc in helper-disc.gcode (for me that was lines 211-711, inclusive) and copy them to the clipboard
11. Use File > G-code Preview to find where the perimeters start in elephants-foot.gcode
12. Paste the gcode you copied from helper-disc.gcode just before the start of the perimeters in the elephants-foot.gcode file (for me that was between lines 205 and 206)
13. Save as hand-edited.gcode, and preview it with the G-code Preview tool to see that it does the correct thing

Once you load that up in the G-code Preview tool, you'll see that the model is no longer distorted, and assuming your elephant's foot compensation is dialed in correctly, the second layer of your model should just barely touch the edge of the helper disc (when printed):

I uploaded the gcode that I created this way so I could have a helper disc that doesn't mess up the geometry of the model. I'm not saying you need to do this; it should still look decent without going through all this trouble. I just wanted mine to be perfect.

And that's what the hand-edited helper disc looks like after printing. The model has uniform elephant's foot compensation all around, and the helper disc is attached to both halves of the model and can be removed cleanly.

If you print this please share your make, I love to see them!