Filament leaking
I've had a problem with a couple prints on my MK2. After reaching a height of about 25-30mm, I get globs of filament and then the nozzle hits the globs and the print is ruined. On my current print job, I checked the head and found an accumulation of melted filament about 8mm behind and 8mm to the right of the nozzle - slightly behind the probe. A drop had formed, but did not fall yet.
Also, there is a layer of filament the covers the nozzle, except for the tip.
I had brushed the nozzle and surrounding area off with a brass brush before starting the print job (the nozzle had no plastic covering it when I started). I paused the print and brushed it off again, then restarted.
I'm using Inland silver PLA, but I've had the same issue with Matterhackers blue PLA.
My next step, presuming this print goes OK, is to take the hot end apart to see if I can find the leak. Any suggestions before I get the tools out?
Re: Filament leaking
Maybe it is not leaking at all.
I had these sort of problems until I installed the silicone sock on the i3 MK2.
The mechanism is this: Thin flossy bits of filament are blown against the hotend and melt again, until there is enough for it to drop onto the print.
I don't understand why Prusa don't like the silicone sock, in my experience it is an essential piece of kit and it has never cause any trouble so far.
Re: Filament leaking
Where would one obtain said silicone sock?
Re: Filament leaking
Depending on where you are from searching for prusa i3 silicone sock should do the trick. Ich would recommend to cast one yourself. Here is my make https://www.thingiverse.com/make:384804
I have been using it ever since and it still looks like at the first day.
Re: Filament leaking
Depending on where you are from searching for prusa i3 silicone sock should do the trick. Ich would recommend to cast one yourself. Here is my make https://www.thingiverse.com/make:384804
I have been using it ever since and it still looks like at the first day.
Great idea!
That makes me wonder if it would be even simpler to cover the hotend in a bit of oil, then smear high temp silicone straight onto it. YMMV..... 😀
Re: Filament leaking
Good idea about printing a mold and casting my own, but at the moment, I have my doubts as to whether I could get a good print for the mold. So I ordered a 3-pack from Filastruder. Only $10, incl. shipping. Should have it by Friday. Besides, that avoids the issues of having to drive 2 hours each way to get some ABS filament (I'm still trying to get multiple successive good prints with PLA) and all the other issues associated with ABS printing.
Re: Filament leaking
An alternative to the pre-made sock is to buy a roll of 3M self annealing silicon tape and apply that.
Bill
Tagaytay City, Philippines
Founder member of Philippines Prusa Printer Owners FB Group
Sponsor Pillars of God Academy in Bacoor
Re: Filament leaking
Humm. I doubt a sock will cure this. Have you recently changed the nozzle?
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: Filament leaking
I'm with Peter. It sounds like the nozzle hasn't been fully tightened against the heatbreak. This allows melted plastic to ooze out from that gap and create the problems you are describing.
Re: Filament leaking
I took it out, cleaned it and the rest of the hot end with a brass brush, and replaced it with no change. I didn't put a whole lot of force on it, but I tightenit until it stopped. I also checked it and it was still tight when hot. After the first time this happened.
I got the socks yesterday and I'm trying a print to see if they work.
Re: Filament leaking
Please refer to Richard's post. You may have tightened the nozzle against the block and not the heat break, leaving a gap where melted filament can escape.
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: Filament leaking
I will double check. With the silicone sock on, my 11 hour print finished with no problems, although there are some very fine strands that I hadn't seen on any prints I've done previously.
Update:
I took the sock off and found some filament that had accumulated inside. Since I had changed colors, I know it was from this latest print. As I was cleaning it off, I noticed the block the nozzle screws in to was turning a little. I'm going to dig into the manual to check, but I'll likely not do anything until after vacation, which starts Tuesday.
Re: Filament leaking
This morning I cleaned the block off after heating it up, then ran 8" of cleaning filament through it. I loosened the nozzle, when hot, then tightened again. Ran a 45 min print, 2 hour print, and 30 min print with no problems. Currently have a 12 hour print running for 4 hours with no globs or signs of leaking filament.
Re: Filament leaking
A few more 10+ ours prints and no problems.
Thank you all for your help and advice.