clogging, jamming, possibly PTFE tube issues
 
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clogging, jamming, possibly PTFE tube issues

Hi there,
I've been mostly happily printing since October on my MK2S. Recently I wanted to try some Carbon fiber and Glow in the dark material. I purchased the Olsson Ruby, and got it installed. Once I got re-calibrated, I did a couple prints with PLA, and they turned out great, probably the smoothest best looking first layer since building the printer. I then tried the roll of Glow in the Dark PLA I had got when I bought my printer back in October. I had issues right off the bat, clogging, wouldn't print well at all. Went to Amazon, re-read reviews of this filament. Mixed reviews, some good some bad. So, I went back to my PLA that had been printing fine both before and after nozzle change. Still wouldn't print right, figured may be a particle stuck in there. Did some atomic pulls, they looked ok, but I noticed that I had a nice looking cone, then about 2 mm up it actually got thicker for 1-2mm, then skinnier, like a little band of wider filament after melting then solidifying. I then remembered when I got my printer, the PTFE tube going into the hot end had a burr in the lip that would not allow filament to pass. At that time I took tube out, cut a new tube and put back in. Have been printing since.

So, I disassembled the hot end last night to check tube, It looked fine. Re-assembled, re-calibrated, and then tried to print. It started printing, great first layer, went about my movie watching. Started to hear the extruder clicking about an hour in, and found I had a partial clog that was limiting the flow. Did a pull, some funk same out, looked almost like PTFE material(it was white, have not been printing in white). I heated up the hot end and was able to feed filament, and seemed to flow out nozzle when manually pushed through. I went to bed as I didn't want my exhaustion to cause any other problems.

ok, after that long story, was looking on forum today for PTFE related issues. Found a Prusa article about "prepping" your PTFE tube by adding a taper and chamfer to the tube. When I did my original build and had to use a new piece of PTFE I did not taper or chamfer it. As I said before it was printing mostly ok, but It caused me to think back, and I have had inconsistencies in the overall quality of prints, which have seemed to be tied to flow. I've done extruder calibrations a few times, always close to where I calibrated it. Could the tube be causing these issues? Is there a good way to taper and chamfer a tube? I tried using a razor knife, but could not get a uniform taper, I got ok results using a drill for the chamfer. I may be grasping, but I'm kind of lost where to begin as it seems to be perfect storm of New nozzle, maybe some bad filament, or PTFE tube.

Sorry for the book, I was an English major. Haha!

Posted : 30/01/2018 6:55 pm
alexander.s27
(@alexander-s27)
Estimable Member
Re: clogging, jamming, possibly PTFE tube issues

I get those tubes (not that I would need a lot, but still...) directly from the Prusa shop for just a few cents,
just to go with other parts when I am ordering. Certainly the shipment costs are different for me in Germany....

Having to chamfer a PTFE tube myself I would use e.g. a cordless drill as lathe, maybe with a fitting drill inside the tube for sturdiness
and a suitable knife-edge or sanding paper for the chamfers...

Posted : 30/01/2018 7:09 pm
Closedquestion
(@closedquestion)
New Member
Topic starter answered:
Re: clogging, jamming, possibly PTFE tube issues

Yep, I found them in the store. Ordered 5, and a new PEI sheet to make the $11 shipping here to the US worth it.

I have no idea if it will solve my issue but it’s worth a shot.

I have some cracked parts that I had been trying to hold off replacing(they have not seemed to effect print quality, and are not related to this issue) which will require total printer disassembly. Was going to wait until my 2.5 upgrade got here so I just have to take a pet once, but may have to do it this weekend. Might be a good idea to start fresh, especially with what I have learned in the first few months of printing.

Posted : 30/01/2018 7:54 pm
Jim Cook
(@jim-cook)
Trusted Member
Re: clogging, jamming, possibly PTFE tube issues

Somewhere on the net, and I can't remember where, it was shown how to prepare the conical section of the PTFE tube using a tapered hand held reamer. This reamer was cone shaped. The taper started at the pointed end at zero diameter (sharp point) and goes out to about 1/2 inch at the largest end. This made perfect tubes for our printers.

Posted : 30/01/2018 8:59 pm
JoanTabb
(@joantabb)
Veteran Member Moderator
Re: clogging, jamming, possibly PTFE tube issues

Hi Jim,

did you mean something like this?

regards Joan

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK

Posted : 30/01/2018 9:21 pm
Jim Cook
(@jim-cook)
Trusted Member
Re: clogging, jamming, possibly PTFE tube issues

Possibly. The main point was a reamer that can fit into the small tube. I'd give that a try, it looks good.

Posted : 31/01/2018 12:08 am
Jim Cook
(@jim-cook)
Trusted Member
Re: clogging, jamming, possibly PTFE tube issues

Looking at it closer I don't see a cutting edge on the reamer. I'll drop by my model shop and see if they sell them.

Posted : 31/01/2018 12:12 am
Closedquestion
(@closedquestion)
New Member
Topic starter answered:
Re: clogging, jamming, possibly PTFE tube issues

I had no issue drilling the end with a 3.5mm bit. only issue was getting the conical taper on the end down inside the heat break. Today after work I disassembled the v6 again and was able to use a pencil sharpener to get a small taper on the downward end, and drilled the upward end out just fine. I've re-assembled it all, and I'm 90 minutes in on a 2 hour print. It's the one that failed on me last night with clogging. So far, so good. First layer was good, and all else has looked pretty good. I have some ringing, but that's from 2 bad bearings which will be replaced by Misumi rods and bearings when my 2.5 upgrade arrives.

Posted : 31/01/2018 12:52 am
Jim Cook
(@jim-cook)
Trusted Member
Re: clogging, jamming, possibly PTFE tube issues

Joan, thank you again. I went to my local hobby shop and mentioned they tool you suggested and he had one. It does have a good cutting edge and I'm able to modify the PTFE tube so the i.d. has the proper tapered shape. Thanks again.

Posted : 02/02/2018 7:14 pm
JoanTabb
(@joantabb)
Veteran Member Moderator
Re: clogging, jamming, possibly PTFE tube issues

I habe two similar reamers and both have sharp edges.

Regards Joan

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK

Posted : 02/02/2018 7:56 pm
ronnie.y
(@ronnie-y)
New Member
Re: clogging, jamming, possibly PTFE tube issues

hi, i am having the exact same problem. so does your problem solved now?

i am exhaust of this problem ....

thank you

Posted : 15/02/2018 8:24 am
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