Anycubic Kossel vertex reinforcement

(old 2019 design imported from Thingiverse)

I was planning to print some of the other vertex models I found on thingiverse, but they appeared to have a bit too much clearance for my liking, or they didn't quite fit the 3D model I was using (which I've found to be extremely accurate).

I started playing around in FreeCAD and realized that the Anycubic Linear Plus does not use the method (that I'm familiar with) of aligning the outside arc with the junction of the lines extended from the inside of the extrusions - it's off by a very odd amount which alters the relationship of the extrusions. Once I figured this out, I was able to model a reinforcement bracket that fit extremely snugly and slides into place without so much as filing.

I designed this to have a broad shell, rather than a skeleton, as it's much more rigid. After printing it, I think it looks better too. :)

The bracket has protrusions that go into the extrusions, ensuring the alignment is consistent.

The opening for the vertical extrusion also has two more shallow ones along its sides that allow the part to be snapped into place, then slid (with resistance, it's very snug by design!) down to the horizontal extrusions.

The legs are longer than the more common models, matching up with the length of the stock vertex parts.

You may notice what appears to be a lack of holes in the model. The holes are there, but with a 0.4mm wall on the ends of the vertical holes and a 0.16mm floor on the bottom of the horizontal hole. This is to prevent the need for supports when printing small-side-down as simple bridges will be printed (preview in your slicer to see this).

See below for post-print cleanup.

The holes and reliefs are sized for M5 button-head cap-screws (as can be seen in the pictures). If you use all available holes, you'll need 10 screws per bracket.

The cube in the pictures was printed after I installed these reinforcements and switched to a flying extruder (and reduced my retractions to 0.4mm).

I picked a font that was as close as I could find to the stencil font Anycubic uses.

If anyone knows of a (free) font that's closer, please let me know and I'll switch and regenerate the STLs.

Print Settings

Printer Brand:

Creality

Printer: 

Ender 3

Rafts:

No

Supports: 

No

Resolution:

0.16mm

Infill: 

12.5% Cubic (for diagonal strength)

Filament: Inland PETG Tranparent Green

Notes:

You may need to enable "print thin walls" in Cura for this (I don't know the name in other slicers). Use your slicer's preview function to ensure the vertical holes all have single-pass walls on each end.

I used a 5mm brim then reduced it to a 3mm brim for some of them, but I'm not sure that's necessary (depends on how well your print surface holds onto filament). I printed one without brim and it came out fine, but it came off the bed so easily, I'm amazed it finished. :)

I used PETG for this. PLA may work and will be more rigid, but may be more difficult to snap into place (you may need to file or sand down the shallow extrusions for the vertical column).

Print upside-down as shown in the pics and you won't need supports.This has a secondary benefit of an extremely accurate geometry of the parts that matter (as long as your printer has been squared properly).

If you print right-side-up, you may get warpage of the part that comes into contact with the horizontal extrusions (I found out the hard way).

Post-Printing

I used a 4.5mm drill bit to clean up the skins covering the holes and a simple deburr tool for the brim. You can see in the pictures that they clean up nicely.

Category: 3D Printer Parts