Parametric Yarn Gator

Update 1 (2025-02-04): added a basic compliant snap-closure, improved built-in supports

This is a print-in-place model. I did my best to make this stable and consistent to print without manual tuning / supports. Some recommendations:

• Use a low-warp filament / printing setup -- you may get binding between moving parts on lower layers if the warping is too high (carefully fix it with a knife)

• You should bump up your perimeters until the long thin parts have no infill (eg 5 or 6 perimeters with default settings and 0.4mm nozzle) -- this will greatly increase strength and may speed up your print time, because there is barely any infill, so it's slow to print it

• Use high cubic / gyroid infill, eg 50% (axle interior)

Strength / stability adjustments in the model:

• Printed in a vertical orientation for a strong hinge (ie, avoiding layer lines along the shear force plane of the hinge)

• Clipped circles everywhere for easier bridging, better bed adhesion, better tolerances, and to strengthen the long thin parts

• Minimal brim / supports baked in (can be deleted easily in slicer / FreeCAD) -- this model has small footprints on the bed with steep initial overhang, so a lot of support is needed, but a full brim is annoying to remove and wastes filament

The FreeCAD parameters control:

• the number of holes,

• the hole sizes,

• the thickness of each component, and

• the clearance / tolerance value between moving parts

FreeCAD's solver tends to mangle sketches when using lots of geometry modifications (like patterning pockets across an object)... Current version seems stable, but I added STEP files for 3, 4, 5 and 6 holes for most use cases.

Defaults: 5 holes, 18mm hole size, 4mm layer thickness (~17mm total thickness), 0.4mm tolerance / clearance.

Some extensions could be to add a base or magnet indents, like this similar project:

https://www.printables.com/model/1541780-yarn-gator