Doron Velta flying extruder mount

Since I didn't like the stock bowden extruder mount on my Doron Velta I went on and designed a flying extruder version. This approach uses 3 tension springs to keep the extruder centered, and allow reducing the length of the bowden tube between extruder and toolhead to around 120mm

BOM

• 3 M3x6 BHCS

• 2 M3x12-14 BHCS

• 1 ECAS coupler, check the body diameter without flange to know which piece to print

• 3 voron spec zipties

• 2 M3x5x4 heatset inserts

• 3 tension springs

  • 0.8mm wire 6mm OD 60mm length (what I used, had to stretch them to around 90mm)

  • 0.4mm wire 6mm OD 60mm length (ordered as replacements, will test them)

  • 0.8mm wire 6mm OD 90mm length (what could work best but untested)

ASSEMBLY

I tried various configurations, and what ended up working is having the extruder upright, otherwise the bottom ptfe tube section will bend too much.

• Print and install the modded carriages, pass one end of the spring in an M3x6 bolt and screw it in the new carriage hole on top

• install the ECAS coupler as well as two heatset inserts on the extruder mount, mount the extruder with the M3x12-14 bolts

• secure the other end of each spring to the extruder mount with zipties, leave them loose for now

• add around 120-140mm of ptfe tube from the extruder to the toolhead, keep it long at first since you can always shorten it.

• tension the springs by shortening the ziptie loops, then check movement by pulling the toolhead opposite of each corner. You will feel some resistance but not too much, the toolhead should snap back around 1cm. Test and repeat until you are happy with your springs tension.

run a speed test to see if your printer binds or has other issue, mine reached 600mm @ 20k accelerations with this setup without issues, with the flying extruder wobbling a minimal amount.

NOTE FOR ENCLOSED VERSIONS

I can't ensure your setup will work if the printer has panels on, since when the extruder is at the top you will bend it and the top ptfe a bit. Having the bowden tube also go through the top panel will make things worse! In my setup I simply route it to the side, using the old bowden extruder mount to hold the ptfe in place

CREDITS

Tanks to wu7z01 for the initial approach used to derive this design, and rogerlz for the awesome printer design