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Full Version: Filament getting massively tangled around gear in extruders on purge-retract script
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This is probably a better sub-forum than the other one I posted in.

Basically see image, got it working from a print perspective with [S3D 4.0 / Rostock Max V2 / Flying mount / 1x PETG + 1x PolyC]  - but it runs for about 10min then this happens:

[Image: bkilS5x.jpg]

Since that pic Ive added tubing and filament feeds, trying to keep it rigid and controller above the extruders, made no difference.. well infact it might be worse than not having any tubing at all. With the flying mount setup (as recommended by user guide) the distance above the extruders is pretty huge, 300mm+, I suspect this is too far on a Delta to be trying to rapidly retract (via purge macro) filament. 

Im thinking of removing the tubing between the extruders and spool and leaving it open air. 
Super messy looking but less resistance?  What tweaks to the purge macro could be suggested to make it less severe? Any other ideas?
@kodachrome

Can you please upload an updated picture of your current setup? That old picture does not reflect the proper assembly instructions. Please make sure you followed the assembly instructions exactly according to the documentation. Post the updated picture so we can help diagnose the issue. Thanks!

BTW 300mm of PTFE tubing should be totally fine for rapid retractions. Just make sure you have the Nylon Collet Locks inserted! I noticed that your picture does NOT show these collet locks.
Ah yes, the collet locks were removed as I was starting to dismantle to clear out the mess. There are otherwise on.
Regarding following the assembly instructions exactly.. hmm what am I missing then?

"Cut the bowden tubing to your required length using a utility knife to ensure a clean and flat end.
NOTE: Shorter bowden tubes produce better results. A bowden tube length of less than 400mm is HIGHLY recommended.
Insert the remaining tubing into the Collet at the top of the ProStruder and push it down to the drive gear."
"


I should correct myself though, the full length to the spool on a Rostock Max with flying mount is 410mm (just measured), its a tall printer.

The other end is of course going to the Y-piece, below the problem area so likely not related to this issue.

See images below, what do you recommend?

[Image: nJl6caX.jpg]

[Image: OZY7PCF.jpg]

[Image: r0JFrIg.jpg]

You will note I better balanced the flying mount in the update pics and doubled up on the anti-slip tape on the top mounted bowden tubing just incase it was moving around (and collets left in for pic this time!). The top bungie cord lifts some of the weight from the flying mount as the whole assembly is too heavy for my carriages otherwise.
@kodachrome

It looks like the bowden tubes are relatively short so that is a good thing. The length that matters is the length from the output of the extruder to the input of the ProFeeder. It looks like that length is about 250mm so that should be fine.

Have you tried printing single color prints yet? That is the first step in debugging and it will make it much easier for us to fix the issue. Please try printing a single color print with 1 extruder and post your results. We will then proceed from there!

Also, please post all of the relevant specs:

- Layer Height
- Printing Speed
- Printing Material
- Printing Temperature
- etc...

EDIT: One thing I noticed is that the extruder with black filament does not have the PTFE tubing pushed all the way in. The PTFE tubing that is inserted into the bottom of the extruder should be pushed all the way in so that it is right up to the drive gear with as small a gap as possible. This is important to prevent buckling of the filament.

EDIT 2: I cannot see from the pictures, so can you confirm that ALL of the collet locks are inserted? (for the ProFeeder and the Hot End?)

EDIT 3: Can you post an up close pic of the Prometheus V2 hot end and ProFeeder? It looks like your hot end is using the V1 heat sink... it should be the V2 heat sink.
Thanks for the detailed suggestions!

Single colour prints fine.

- Layer Height 0.2
- Printing Speed 45-65 tested
- Printing Material PC and PETG (all I have at the moment)
- Printing Temperature (275 - 286 tested, for the PC)
- Retraction 1.5 to 3mm tested, coasting and wipe usual values in S3D



EDIT1 answer - fixed
EDIT2 answer - fixed, I thought I lost them then forgot the bottom ones. Found and inserted.
EDIT3 answer - This is a V2 Beta version. Didnt know there was a difference in the collet vs the non-Beta V2. Swapped over to my release V2 version (as you see I buy all your stuff :p ).

Unfortunately its all ready to go with a 0.6mm nozzle (and this is a spegelius question).. his script errors out on 0.6mm nozzles with "ERROR: Feed rate too high! Aborting"


I've tweaked extruder.py and analyser.py to raise this limit but really need spegelius to comment as Im not great on python nor actually understanding the limits reasons. 0.6 isnt like.. all that big!
@kodachrome

I had a similar issue when I first started using the Prometheus System, make sure the grub screws on the drive gear are not loose and I printed some other collet locks off Thingiverse as I found they didn't hold the PTFE.

J.
@3DPrintingReviews thx for the tips. Pretty sure mine are tight, hard to check without dismantling I guess?

FWIW Distech, I made all the changes above, new hotend (V2 proper) etc and it did complete a print, but on the next attempt it wrapped the PETG around the gear again..
You should just be able to reach the grub screw from the side.

Might also be worth checking you are using the correct filament change gcode as I remember having an issue where the old colour hadn't retracted enough and the new filament didn't have anywhere to go resulting in it backing up at the extruder.

J.
@kodachrome

If you are printing PETG, then the cause of the problem could be that the filament tip is "stringing" on retracts and then causing jams when it is reinserted. This is why we do not recommend PETG for dual color prints (PLA and ABS are fully supported). We also HIGHLY recommend drying your filament before printing. The last few warnings in RED in the User Guide outline the important things to note before starting your print. It would be best to read through those and start with ABS to get started!

Let me know if you have any questions!

EDIT: Also, please confirm that you have your hot end assembled according to the instructions in the user guide. Please post a picture!
I think you are correct on the PETG and being honest, to make matters worse, this PETG was shipped from one side of the world to another when I moved (NZ to IE), via sea and has been sitting around for 6mths. Clearly a poor candidate (though Hatchbox is a good brand IMO).. but as I said I was keen to just use it up and this is what I have on hand!

I dont like ABS for various reasons, mainly the smell, warping and the poor adhesion to PEI build plates.
What do you think of this stuff for dual printing.. looks awesome otherwise and just a little more $$ than vanilla:
http://www.matteforge.com/
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