Print greats then stops

I built a prusa I3 and it works great with PLA on smaller objects. When I try to print past maybe 45 minutes or an hour it looks great and then just stops extruding. The melted filament stops coming out of the nozzle and the extruder starts clicking. I have tride temps from 190 to 225 in 5 degree increments and it does it across the board. I have slowed it way down to 40 and sped it up as far as 80. I have tried from 90% to 130% filament feed. It always does the same thing.

Like I said, it works great on smaller objects. I have printed a bunch of arduino cases, replacement parts for my printer, some rocket nose cones, etc but when I try something larger it always stops.

Any ideas?

Thanks
Jeff

Heat is creeping up the hot-end into the area that's supposed to be "cold". Are you running a cooling fan on the hot-end?
Is the hot-end clamped to the motor? Does the motor get hot?

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

So that was my thought too but I can't be sure. I am running a bowden setup and the motor doesn't really get hot at any rate. I have installed a E3D V6 head and it does have the fan running that came with it.

So would you think cooler temps and running faster would help? Maybe I am doing the wrong thing by slowing it down and running a 210+ temp. It has been pretty hot around here lately compared to our normal weather and it is pretty warm in the house too. That could be making things worse.

Is it an original?
If not the hotend will most likely be with a too small diameter somewhere plus the heat break is just drilled and not polished - this causes massive friction once the filament is hot.

No it's a knockoff but I polished it somewhat with a dremel. I can polish more if you think that will help. I can't afford an original right now so I need to make this one work if possible. It makes nice prints so long as you aren't after anything too big. Of course I built one with a 270x200 bed planning to do larger stuff.

I had the same issues with a knockoff that I had polished up and in which I had replaced the ptfe lined heat break with an all-metal one. Heat would creep up the heat break and clog things up. The fix was to switch out the all-metal heat break for the original ptfe lined one. No issues since then.

Take the nozzle out, get a length of filament that ran through the extruder and has marks on it - PLA is great here as it is hard and stiff.
Push this filament by hand through the hot- cold-end assembly.
On mine it was evident that the top hole had a little rim where the damaged filament would get caught.
Also the inner diameter was quite tight, 3.0mm to be precise - I drilled that out to 3.2mm, using 3mm filament here, for 1.75mm drill out to 2mm.
And as said the heat break itself was just drilled and had a lot of marks in it.
Took me about a sheet of 800grid paper, rolled in little chunks on a steel wire to clean that.
To finnish I polished a while with Autosol metal polish as it rated for stainless steel.
Now it does not matter if I feed ABS, PLA, Nylon or other materials, they just print.
Only when coming from PLA to high temp plastics I sometimes get a clogged nozzle from the bunrt PLA if I did not flush properly.
But PLA I can actually print without fan on the cold end if the print does not last more than an hour.

So I was a dummy at first and thought the barrel was already lined because my others had been. I was not sticking the tubing down very far and I was having all kinds of jam issues. Then I started sticking the tubing way down and I got really good success with most objects. I just printed out a complete set of replacement parts for my I3 yesterday and tonight and had zero jams or misprints. But if I try a larger object it will go about an hour or a little more and then jam up.

I'm trying to print one of those handheld PSP style arcade game cases for a raspberry pi. Actually I need to print three. One for me and one for each of my boys. The cases are about 232x71x26mm and they usually get about 25% and then jam.

So tonight I ordered another Jhead and several spare feed pipes/barrels for them. My plan is to polish the fool out of one of the replacement barrels and swap it into the new head. Then work on my original head and barrel. I also bought new tubing to replace what I have been using because I have been running this thing nearly non stop since I got it assembled 3 weeks ago. I already printed out and mounted a dual mount so I can hang 2 heads to test if I need to.

I will report back whether or not I have success.

One thing I know is that I do get further on the big prints if I run 200 degrees and 75mm/s than I did at 220 and 50. That's more obvious to you guys but it wasn't to me. If it stopped melting I just kept turning up the heat. I'll figure it out eventually but I really appreciate the help.

Jeff

Is it possible your USB is resetting? Are you able to print from an SD card?

My printer was doing fine for awhile the last two prints I started stopped after 10-15 minutes, so it is likely time to go back to the SD card for me.

I only printed via USB a couple of times when I first built my printer and only use SD card now so that's not it. I read a few comments where people had similar issues to what you did so that's why I stopped doing it early on.

So the issue is not fixed but it's better.

I tried to polish the hotends I had. Apparently I have no patience with little things and after quickly losing my will to live, I decided to just buy better ones.

I read a bunch of reviews and purchased these: [www.amazon.com]

They seemed to be a good start for a decent price and I figured if I needed to polish then at least I would be much closer to done with these. Before I swapped the hotends I did some tests as you guys recommended and I could feel the filament snag in my old head/hotend setup but it went through silky smooth with the new one.

I am now running cooler (190-200) instead of hotter (210-225) and I run faster at around 80mm/sec instead of slower (40-50). I get much further along and can even complete larger items that I could not before although I am yet to be able to complete the case for the PSP game handheld.

More tests to come but I am getting closer. Thanks for the help.

It finally works.

It was about half the head and about half the software apparently.

After switching to the new and better hotends I was getting much further but could still not get it to complete 2-4 hour prints.

I had been using Cura and was beginning to wish for more control so I loaded up Slicer. Everything I printed immediately looked better and I have completed a 3 hour print and a 4 hour print with no issues.

I really don't think the software switch alone would have done it as I got drastic improvements when I pursued a smoother filament path as you guys suggested.

So at this point it seems that I can successfully print anything that I can fit on my 270x200x190 bed.

Thanks for all your help.

Jeff