20mm Plastic T-Slot

20mm Plastic T-Slot - Rev 2
Completely redesigned; the new beam prints faster and is stronger both against deflection and torsion.

UPDATE: Added DXF of Profiles. Naming convention is [dimensions]-[bolt size]-[Wall Thickness]-[Multiplier]. We are starting to prefer 1pt6 (1.6) wall thickness profiles and find printing them No Infill, 1 Extra Loop, No solid Layers, with a trace thickness of .8mm results in a quick and adequetly strong beam.

These beams are being designed as the main structural component for a 3d printer though arguably they are of more use as a general hobby framing and mounting set. That said they are designed with both printing and commercial extrusion in mind.

If printed in ABS, they can be solvent welded with the aid of a T-Slot Welding Jig http://www.thingiverse.com/thing:13598 and ABS Glue http://www.thingiverse.com/thing:14490 . A center hole increases the beams second moment of inertia while aiding in fusing beams.

PLA beams are more rigid though they are not as easy to fuse into various lengths.

Hardware
An example of Friction Fit hardware is located -
Here - http://www.thingiverse.com/thing:9797
& Here - http://www.thingiverse.com/thing:13599

The standard beam profile is meant to accommodate both M3 hardware as well as 6-32 nuts and bolts. Both bolt heads or nuts will fit in the slot with an insert provided to help guide and captive M3 nuts. 6-32 Nuts will captive natively.

Alternative profiles are provided for M4 / 8-32 hardware as well as dedicated M3 and 6-32. All profiles are located in "20mm Profiles - Printing.skp" Use the 'Push/Pull' tool to create a profile of the desired length.

If the printing instructions are followed, these beams can be printed fast (going at even a moderate pace we're able to produce all the beams needed for a Prusa in under 12 hours). While the beams can technically be printing with any working profile, they will not print as quickly and may not perform as intended structurally.

Files
100mm Beam.stl - actual height is 101mm to allow for loss during welding
20mm Test Beam.stl - shorter for testing settings
M3 Nut Insert.stl - use with metric hardware
20mm Profile-Printing.skp - profile faces for printing and creating different heights
20mm Profile-True.skp - diagram of a properly printed profile
20mm Profile-Printing-pt4.skp - profiles based on 0.4mm widths, contains a M5 profile
M3 Nut Insert.skp - source file for insert

Check Back For
T-slot Profiles for Thing-O-Matic, Ultimaker & Mosaic at various resolutions, speeds.
OpenScad version to ease design of compatible hardware and accessories.