Heavy Duty 2040/4040 Extrusion Bracket

About

I had a heavy kitchen tabletop I wanted to salvage as a printer table. I used dual-slot 4040 extrusions but the brackets were not strong enough. This is the solution.

These joining brackets are ~240mm long. They must be printed in ABS or another suitably rigid and strong plastic.

Bill of Materials

• Printer enclosure that is stable above 40C
• 150g+ of ABS
• 8x M5 x 16mm socket head cap screws
• 8x M5 lock washers
• 8x M5 tee nuts

Printing Instructions

Rotate the model 45 degrees if you are printing on a 220x220 build plate.

• Material: ABS/ASA
• Enclosure temp: 45C with unmodified ABS
• Walls: 2mm
• Infill: 30% or higher
• Adhesion: brim and adhesive
• Layer height: 65-75% of nozzle diameter*

* This is 0.25ish to 0.32ish for an 0.4mm nozzle. Thicker layers improve strength.

Installation Tips

• Lock washers are not strictly necessary, but strongly recommended
• Use roll-in tee nuts instead of drop in.
• If you have any warp in your print near the edges, the screw holes closest to the warping will be unusable. This is okay if you still have 3 usable screw holes per side.
• Carefully check the angle and flushness of the bracket during installation.