Expandable peg loom

the holes are 5/8 in (15.67mm) which should be perfect to cut and drill dowels.
it's intended for use with Plarn, but can be used with other materials.

make these on the cheap and expand all you want.

I would start with a 25% infill, but if you aren't happy with the strength, go with 50%

I haven't printed one out yet, but if you do, Please post pics