After many tweaks, here are my conclusion:
The Flexystruder is ok for small parts, but issues are increasing with the length of filament spent.
I fully agree with kirispupis, this design is not ready for sale.
There are major flaws imho.
First: the hole diameter for the main serrated shaft is way too big, leaving a large gap between it and the housing. 8.2mm on the sla file as well as on the fabricated part vs a bolt diameter of 7.8 = .4 mm. Considering that the shaft itself may be slightly misaxed, this could represent an issue.
I’ll try building a corrected part to fix this.
Second: the unit I received was not tuned. The filament path was not in line with the hobbed part of the bolt. Need to play with the washer order.
Third: Cura’s default settings should turn off retraction and slow down the speed I think. Going backward with a flexible filament maybe tricky. I’ve also increased the nozzle temperature to 230 C (vs 222) in order to offer less resistance after the hoobed part.
Fourth: The PTFE part was so badly cut that it’s leaving a really big gap between it and the shaft by more than 1.5mm. This is neatly inappropriate.
Fifth: Construction should be modified to accommodate such maintenance and to prevent damages done on good parts.
Is there a Solidworks part / assembly somewhere so I can rework this? I really need to get this working for the next few days…
I’ve ordered an other PTEF tube and wondering if I’ll build another unit.
I’ve already spend too much time on this. Desperate. hElP!