who knows these things real well. Cannot get it to print

[Tachout]

I can put it in, and it pushes in with no resistance until I feel it start to melt. I have then pulled it out tried it with vegetable oil on it. Still does not help. I am thinking of just ordering a new hot end from Makerfarm and seeing it is all in the hot end getting damaged somehow

[Tachout]

I just pulled the nozzle off and I am pretty sure it is clogged. I think I will just order a new hot end and see if that helps.

[beerdart]

Soak the nozzle in acetone to remove the old plastic. Or burn it out with a butane torch but make sure you do that outside..

[Tachout]

Thank You beerdart. I have my old one soaking in a cap full of fingernail polish. Stupid me, I looked at the bottle and it states non acetone so I am going to run to the store and grab a bottle of Acetone. I have ordered the new nozzles anyway just incase. They are real cheap and Makerfarm is located just across the valley so shipping is like 1 day so why not just have new ones laying around just incase. I will see if I can clear it

[BLKKROW]

I have had numerous issues with the Hexagon Hot end and switched over to the E3D V6 and have had zero issues since.

[beerdart]

Most Hotend problems is under-cooling or over-cooling. (Other then a clogged nozzle) The Hotend itself is a very simple device no mater the brand.

Tachout what extruder? Greg's?

[spaceorange12]

I have had numerous issues with the Hexagon Hot end and switched over to the E3D V6 and have had zero issues since.

Agreed. Love my e3d, can't believe I wasted so much money on cheaper options

[Alibert]

I have had a similar problem with an all-metal hotend and PLA in a bowden setup. Because of the bowden I needed to have a few mm of retraction to counter oozing. With ABS I could get succesful prints most of the time (not always, it would occasionally jam), but with PLA the hotend would always get clogged somewhere during the print. First layers were nice, then the extruder would get a hard time and jam totally. I have a Bondtech setup on that printer and it would put so much pressure on the filament that the 4mm couplings would spring loose, releasing the ptfe bowden tube (and piling the filament next to the printer).

I finally nailed it down to the heatbreak (the threaded part between the cooling body and the heating block). After taking the whole hotend apart (including the stuck PLA), I found that the PLA was stuck somewhere in the heatbreak and could not be removed by any force. I used pliers and a vice, so it was really, really tightly jammed. My concusion was that the PLA had glued itself to the inside wall.

Aparently PLA sticks quite well to metal surfaces. It seems that polishing may solve the problem (http://www.dta-labs.com/products/prometheus-v2), but I took the easy way out and exchanged the heatbreak for a teflon lined one I found in my spare parts bin. Used my Dremel to make it fit the inside of the cooling body as the top needed to be thinner. Result: problem solved. I have been happily printing ever since (4 months or so) without a single jam and at retractions up to 6 mm (!!). I just never run the nozzle higher than 260 C now, but I only need 250 for ABS and can do with 235 for PETG and 220 for PLA at high speeds. As I can buy teflon lined heatbreaks for a dollar or so, it is also cheap to replace the heatbreak if the teflon liner gets over-heated by accident. I now have a couple of the right size as spares.

Some people claim that it is dangerous to run teflon at temperatures near 260 C. However, this is the temperature limit where it still maintains most of its mechanical properties and is the recommended limit for engineering purposes. It actually melts at 327 C, and only starts to decompose at temperature way above 400 C. http://nvlpubs.nist.gov/nistpubs/jre...n6p327_A1b.pdf. Beware however that your themistor is not indivudually calibrated and that your temperature reading can be off by 5-10 C (typical) or even 20 C (extreme).

[printbus]

...thanks to a little investigation was that the filament I had was 3mm filament and I ordered a 1.75 hot end so I thought that must be it.... I am stupid and the last time I ordered filament I ordered the wrong size. I ordered a roll of 1.75 from Colin (and let me tell you I ordered it on Christmas Eve and it was at my house the day after Christmas. Outstanding service). I tried to just load it and no luck. it felt weird like it was too small and I am still not sure if it is not too small for my hot end although I looked at what I originally ordered and the original order for a hot end was for 1.75 hot end....

For the record, proper 3mm filament simply will not feed into a 1.75mm hex hot end. No way, no how. Use a calipers to measure the diameter of the feed hole at the top of the hot end. IIRC the feed hole diameter is about 1.85mm on a 1.75mm hexagon hot end. I don't know what the diameter should be for a 3mm hot end, but it has to be larger than 3mm... If it is, you have a 3mm hot end.

For all we know, your problems may be simply due to not configuring the slicer for the actual size of your filament. Measure the diameters with a calipers and report back. Tell us the filament diameter setting you're using in Slicer. If you have been using 3mm filament because that is what you really have but have been configuring slic3r for 1.75mm because that is what you think you have, the slicer is going to try to push 3x the proper amount of filament volume through the hot end. The narrow gap between tip and bed on especially the first layer would lead to an incredible amount of pressure on the filament being pushed into the hot end, and it'd be just a matter of time before you carve into the filament.

EDIT: Colin (and company) makes mistakes. I have a roll of 3mm filament from them that is useless to me as a first-hand example. If the filament you had been using was ordered from MakerFarm at the same time as your printer, maybe they confused orders and kitted your box with a 3mm hot end and 3mm filament instead. Knowing what you actually have is more important than knowing what you ordered.

...Aparently PLA sticks quite well to metal surfaces....

Part of the problem is that PLA expands slightly when it cools. If fluid filament gets pulled up into the heat break and it cools, you run the risk of that swelling forming a pretty good plug in the tube.

Chadd, before you run off and buy an e3dv6 hot end because of the positive reports here, be aware that it can be argued as more susceptible to plugging in the heat break than the hex. This isn't meant as a ding against the e3dv6 - I have one myself. The issue is simply due to the fact that the e3dv6 has a much sharper transition between hot and cold elements of the hot end. Multiple users here have had to back off the retraction distance when they transitioned to an e3dv6.

[Chachin]

For what it's worth, I had the same frustrating experience of carved out filament in my Greg accessible extruder for the first few months of printing. Then I changed to a different brand of filament and all is gravy now .

Chachin..