Blockage troubleshooting.  

Re: Blockage troubleshooting.

OK, so this is the pencil sharpener I use to chamfer the PTFE tube

Is that WWII surplus? They sure don't make them like they used to.

Re: Blockage troubleshooting.

Is that WWII surplus? They sure don't make them like they used to.

Richard, this is Slovenia in a nutshell... 😉

Peter

Re: Blockage troubleshooting.

Three color squirrel printed in 7 hours. Appreciate your help Peter.

Best,
Steve

Re: Blockage troubleshooting.

Interesting about the ptfe tube. Mine is also not chamfered or tapered on heatbreak side. Been trying to fix extruder missing steps since day one.. will give it a go. I also dont really see a difference between a spare ptfe an mm id. What is the normal id of one from prusa?

Re: Blockage troubleshooting.

Three color squirrel printed in 7 hours.

Great. Very pleased. Thanks for the update.

What is the normal id of one from prusa?

Regular PTFE tubing is nominally 2mm ID; I don't know the tolerance though (possibly ±0.1mm).

Peter

Re: Blockage troubleshooting.

Well I definitely felt a rough spot between PTFE and heatbreak when just inserting filament manually (cold). I did my best to chamfer and taper the PTFE tube on the heatbreak side but still felt an issue (gap).

I then disassembled the hotend, and when reassembling I inserted the PTFE tube first then tightening heatbreak into heatsink until it was flush (had to move up PTFE tube a couple times, added a little more arctic silver to heatsink side of heatbreak), I then re-attach block, and finally re-tighten nozzle. (only a little bit of heatbreak is sticking out of the top of the block, just like it was new). And i can say that the PTFE tube is as tight as possibly against the heatbreak.

So now that the PTFE tube is hard against the heatbreak and it cannot move up and down with the black locking ring, it does feel a lot better! I still however feel a very slight resistance when inserting filament and it gets to the top of heatbreak. But nothing like before.

Testing again with ESUN PLA at 205-215C and manually advancing extruder in settings, I don't get any miss steps on the extruder. However when I go to print V2 Calibration MM PLA, or marvin, it immediately starts skipping steps on the prime line and when laying down the print. Which for the print all I get is about 4 dots, the rest of the line is nothing as extruder is skipping steps.

When I then go to unload or advance extruder its now jammed. I have to then heat up to a higher temp like 255C for a bit and manually push/pull filament after removing the multiplexor. Ugh...

I have also previously tried Hatchbox PLA with same results. I will try again after the hotend work I just did.

However when I try Prusa ABS at 255C it does perform a lot better. I only get a couple clicks/missed steps on the prime line. It is then able to print fine...

I'm not going to accept its now a ABS only printer lol. I think my next action will be to get the correct PTFE tube from PRUSA and maybe a new MM Heatbreak. I did measure the one I had best I could, it is close to 2mm ID.

:-/

Re: Blockage troubleshooting.

Ok, very odd. I decided to print with some PRUSA ABS for a bit.
And now it seems to be printing PLA a bit better now...

Fingers are crossed, So far I am half way through a Marvin.

Re: Blockage troubleshooting.

Wow, Josiah, I could have written the same post almost word for word. 🙂

I can't use any of my PLA from Makergeeks right now, it seems to jam every time no matter the temperature. It was formerly my best filament. Meanwhile, I have cheap PLA from Foxsmart that I've been neglecting for months, and it prints pretty well in the MM printer. Hatchbox seems OK too. eSUN PLA jammed, but it was early in my testing and I had not reseated the PTFE tube yet.

My best guess is my Makergeeks filament needs to be dried. Lots of things to try, so little time. :-/

Re: Blockage troubleshooting.

Ok, very odd. I decided to print with some PRUSA ABS for a bit.
And now it seems to be printing PLA a bit better now...

Yes, I forgot to mention (it's been quite a long time) that it does seem to be that the PTFE need to be "run in" for a while. The prints will get better after a few hour printing.

Peter

Re: Blockage troubleshooting.

The problem is that it is high-precision 1.9mm ID and not readily

Peter do you know where to buy this PTFE tubes ? (I'm in canada and i don't want to buy it from prusa because of the shipping cost)

Re: Blockage troubleshooting.

Peter do you know where to buy this PTFE tubes ? (I'm in canada and i don't want to buy it from prusa because of the shipping cost)

No, sorry, I don't. Leave it with me and I will try to find out.

Peter

Re: Blockage troubleshooting.

OK, more information regarding PTFE tube:

The tube is specifically made for Prusa Research by Festo. No other tested tubing met the precision requirements.

The tube is currently (and maybe for the foreseeable future) only available from Prusa Research. Sorry.

If it helps, I can get some sent to me with my next order and then send it on to you via regular postal service.

Peter

Re: Blockage troubleshooting.

If it helps, I can get some sent to me with my next order and then send it on to you via regular postal service.

I have one order waiting so i'll check if prusa can add some to my order.

Re: Blockage troubleshooting.

After printing for a week and a half I can say that 99% of my blockages have come down to the filament used.

Hatchbox - works
Coex - works
3D Solutech - works
Monoprice - works
Inland - works

MakerGeeks - Jams every time. Every color, every spool, every time.

Re: Blockage troubleshooting.

After printing for a week and a half I can say that 99% of my blockages have come down to the filament used.
...
MakerGeeks - Jams every time. Every color, every spool, every time.

I had that exact experience with filament from my local manufacturer. Ended up tweaking the unload speeds and lowering the temperature. Now it works perfectly.

Peter

Re: Blockage troubleshooting.

How do you tweak the unload speed? I think that would help me a lot.

I managed to convince my Makergeeks filament to print at 230C (the temperature recommended by Makergeeks), but then when it unloaded, it was still a little too liquid inside the steel tube and it formed a plug in the tube. I heated the tube with a heat gun to get it out, but I couldn't get it all, so I burned out the rest with a lighter. Now the tube is working fine again, except that I still can't use the Makergeeks filament because it still takes longer to cool than the filament change routine expects.

(BTW I can't print my Makergeeks filament at a lower temperature because it only seems to melt consistently at a high temperature. 240C or 245C would probably be better, in fact.)

Meanwhile, I printed a very nice dual-color travel Chess board using my Foxsmart filament. I'll show it off soon. 🙂

Re: Blockage troubleshooting.

How do you tweak the unload speed?

By making changes to my post-processor. I can also change the number and speed of cooling cycles - which is how I was able to get PVA and flex to work.

Unfortunately this is not something that is easily achieved with the supplied post processor (or combined Slic3r). It's just that I use KISS to slice and have had to write a post processor for that slicer.

Meanwhile, I printed a very nice dual-color travel Chess board using my Foxsmart filament. I'll show it off soon.

Looking forward to seeing that!

Peter

Re: Blockage troubleshooting.

Hello

I just got my MM setup installed and was having blockages on retraction. I tore the hotend down to find there is no chamfer on the PTFE tube. Whats a good way to chamfer it so its uniform?

Re: Blockage troubleshooting.

Hello

I just got my MM setup installed and was having blockages on retraction. I tore the hotend down to find there is no chamfer on the PTFE tube. Whats a good way to chamfer it so its uniform?

Hi Michael

Pencil sharpener for the chamfer, Swiss army knife reamer tool for the tapers.

Peter

Re: Blockage troubleshooting.

Mine too came with only a chamfer on one end and no taper/chamfer on the other. I've since tapered and chamfered the other end due to a first run blockage. No problems since. The missing chamfer/taper seems to be a trend. Or intended undocumented change?