This is a set of 3D-printable connectors for making heavy duty boxes out of 20 mm square aluminium profiles. The pictures shows how I used them, but they are universal for any size of box, just cut the aluminium profiles to the desired length. There are connectors for just a box, for a box with intermediate brackets, with mounts for 3D-printed wheels and with mounts for a trolley-type extendable handle.
Instructions:
Printer:
Craftbot
Rafts:
No
Supports:
Yes
Resolution:
250 um
Infill:
25-33%
Notes:
Print as many pieces as you need (the trolley on the picture uses 14 pieces, 4 corner pieces, 4 intermediate pieces, 2 pieces with wheel mounts, 2 corner pieces for an extendable trolley handle and 2 pieces for the handle itself). The connectors are quite snug-fitting (0.5mm play), so check your extruded rods if they are indeed 20x20 mm (non-anodized ones can be bigger in my painful experience) and scale accordingly. This prints best with PLA (and is strong enough). If you do it with ABS, you could have issues due to shrinkage: scale to +5%. Warping will also be a problem with ABS.
One note about printing structural parts: Use higher hot-end temp than usual (PLA: +10°C, ABS: +20°C) to get good interlayer adhesion. The prints will be just a bit uglier (e.g. stringing increases), but A LOT stronger.
Assembly
Cut aluminium profiles to desired length in pairs, stick them in the connectors, check dimensions and either glue the profiles in the connectors or use self-tapping screws for a removable construction.
The author marked this model as their own original creation. Imported from Thingiverse.