Whole hotend rotates while trying to screw the nozzle in
Hi
I had the melted material leaking from the top of the heatblock so decided to re-tighten everything properly. I made sure the heatbreak is screwed just the right distance into the heatblock so the nozzle bottoms out against the heatbreak and not the heatblock, leaving the required gap. The trouble is, when I heat the thing up to 280 degrees and proceed to tighten the nozzle with a torque driver, as soon as the nozzle's thread butts up with the heatbreak, it begins to drive the heatbreak out of the heatblock, turning the whole hotend (radiator and all) with it. The effect being, the nozzle ends up flush with the heatblock anyway. I have tried to tighten (up to the point I felt reasonable) the extruder case screws so the hotend is gripped more firmly but that didn't help. Am I making some obvious mistake? I'd hate to have to take the extruder apart...
Zbig
RE:
You need a 16mm Wrench to keep the heatblock in place when tightening the nozzle.
It is tedious to do that as there are the heater cartridge and thermistor wires on the side. The E3D groove mounting is not my taste.
You have to keep in mind that when tightened, the nozzle hex base must not touch the heatblock. Then you are sure the nozzle is touching the heatbreak.
RE:
Forgot to mention that, sorry, but I do hold the heatblock with an adjustable wrench. The trouble is, while the heatblock is stationary, the nozzle, as it gets screwed in, presses at the end of heatbreak and forces it to actually unscrew a bit from the heatblock, turning the whole radiator assembly with it. Imagine trying to put two bolts from the opposite sides into a single nut: you screw one bolt halfway, then you grab the nut with pliers and proceed to screw the opposite bolt in. Then, instead of the two bolts binding securely, the one you are driving actually pushes the opposite one out of the nut by effectively unscrewing it. And that's the thing that seems to be happening to me. The obvious solution would seem to be to hold the other bolt (the hotend radiator) still but that's easier said than done with V6's smooth, polished surface.
RE:
:thinking_face:
Maybe you tighten too much. E3D says 3NM torque is fine: https://wiki.e3d-online.com/E3D-v6_Assembly#Final_Tightening
RE: Whole hotend rotates while trying to screw the nozzle in
Thanks, but I have my driver set halfway between Prusa-recommended 2.5 Nm and E3D-recommended 3 Nm and the whole damn thing begins to spin way before I reach this torque.
RE:
I was thinking I could help. As soon as it turns, it should be good, I would say.
Personally I apply 1.8NM torque as I have a limited torque wrench that size (bought from Triangle Labs).
Slice engineering advise 1.5NM. Phaetus 2.5NM for its Dragon.
And I switched recently to Dragon on the MK3S+ because I was fed up with the tedious groove mounting. Now I'm not afraid to change nozzle.
https://www.printables.com/model/274974-mk3-extruder-body-and-motor-plate-compatible-with-
RE: Whole hotend rotates while trying to screw the nozzle in
And I'm grateful for your responses, sorry if I came across as a jerk. It's just I'm fighting this for a whole day now and got a bit frustrated. I took a closer look at my heatbreak and it appears busted so it's possible that was the original reason for my problems. Either that or it got damaged during the course of my "troubleshooting". Either way, now I have no other choice than to take the whole hotend out and asses the damage. Thank you once again for your help, I'll update this thread with my findings.
RE: Whole hotend rotates while trying to screw the nozzle in
I took the hotend out and turns out the thread got stripped inside the heater block. I thought I was being careful, even got an expensive torque driver just for that purpose but there you go... You're right the groove mounting isn't the best but I'd say the whole design of E3D V6 and the resulting nozzle change process isn't really suited to changing nozzles on the whim. I can no longer see myself changing the nozzle just because a model design calls for that, not after that experience. Oh well, I guess it's Revo time for me... 🙂
RE: Whole hotend rotates while trying to screw the nozzle in
It would have been Revo time for me too if I hadn't some Bondtech CHT and hardened steel nozzles.
RE: Whole hotend rotates while trying to screw the nozzle in
I know the official instructions about removing and replacing the nozzle are confusing, particularly the need to turn the heatblock assembly before removing the nozzle.
I'm surprised that the heatblock threads got stripped with anything close to the recommended torque.
A couple of times when I've had a leak, I've had to disassemble the hot end, and I found that debris (scorched filament residue, etc.) was preventing a good seal between the nozzle and the bottom of the heatbreak. A good clean-up of the mating surfaces of the heatbreak and nozzle corrected it.
RE: Whole hotend rotates while trying to screw the nozzle in
I am having a similar problem using a Nozzle X 0.4 nozzle on my MK3s+. I do not change the nozzle often, as the Nozzle X is very durable. However, I cannot get the nozzle to form a good seal against the heatbreak. Steel nozzle and stainless steel heatbreak means no deformation occurs at the joint. I have tried tightening at 285 & 290C but still get a small leak. The leak eventually drops a blob of PETG on the print, then it gets trampled in by the subsequent layers, ruining the print.
My next test is to add a brass washer between the nozzle and heatbreak to see if that helps seal the leak. I will post an update once I have a result.
Another option is to use a high-temperature sealant on the heatbreak thread, which would help it resist turning in the heater block. It may be tough to avoid some sealant fouling the nozzle/heatbreak interface. That will be the last resort after the washers.
RE: Whole hotend rotates while trying to screw the nozzle in
Update: Attempted installation of the brass washer. Turns out the heater block thread around the heat break was failing, and the heater block slowly pushed off the heat break as I tightened the nozzle. M6 thread stripped. Time for a new heater block.
New heater block installed, and I proceeded with the brass washer between the nozzle and heat break. Since the washer is .016" (0.4mm) thick I ran a first layer calibration.
It is possible that the new heater block alone may have completely solved the nozzle leak. However, other users have commented about having NozzleX nozzles loosening over time. I have been struggling with nozzle leaks since switching to the NozzleX. I think the brass washer may help with this. Here is the washer I used:
260 Brass Tight-Fit Ring Shims - 0.016" Thick, 1/8" ID
After an hour of printing with PETG at 250C I removed the cooling fan to get a close look at the top of the heater block. I found it completely spotless.
RE: Whole hotend rotates while trying to screw the nozzle in
Another update: After about 70 hours of printing with various colors of Prusament PETG, the Nozzle X remains tight and printing has been flawless! The brass washer was worth the trouble.
One challenge will be for nozzle changes to different sizes. Once filament has flowed through the brass washer setup it becomes difficult to deal with. I plan to build a set of cartridges with Nozzle X, brass washer, heater block, heat break and heat sink pre-assembled in each nozzle size I use. This is somewhat pricey, but E3D is not yet producing their Revo 6 nozzles in hard materials.
I will leave the heater and thermistor in the printer, and swap out the hot end cartridges, which is pretty quick. The advantage of leaving the Nozzle X nozzles in the hotend cartridges is that the seal never gets disrupted. Once the Live Z adjustment is determined for each cartridge, changes should be even quicker.
RE: Whole hotend rotates while trying to screw the nozzle in
I avoid changing the nozzle unless I really have to because of issues like this.
RE: Whole hotend rotates while trying to screw the nozzle in
And I, since I got Revo, am changing the nozzles any time I feel like it, on a print-to-print basis. Now I am kind of glad I ruined my V6 during a botched nozzle swap if that's what was needed to make me switch. It really makes THAT much of a difference: it's one of, if not THE single most quality-of-life improving upgrade you can do on a single extruder FDM printer. Come on people, the water is fine. They have finally released the hardened Revo nozzle (ObXidian). It's currently out of stock due to the demand but I hope those are just temporary issues.
I avoid changing the nozzle unless I really have to because of issues like this.
RE: Whole hotend rotates while trying to screw the nozzle in
I would not be afraid of changing nozzles, if there is indeed a reason to do so.
Just be careful, as you will be working on the hot end when it is indeed hot. Also be sure to pay attention to detail in being sure that the mating surfaces of the heat break and the nozzle are spotless and free of debris. Even a small crumb of scorched filament residue will prevent a good seal and you will have a molten filament leak.
At first when I got the Prusa, I printed one of those plastic torque wrenches, but recently I just tighten it by feel, open-end wrench (spanner) on the heat block and socket with a small breaker bar on the nozzle and use 'two fingers' of torque. 😉 You will get the feel when it is right.
Always do a look-see sanity check when you are finished, to be sure that the gap above the nozzle looks correct as compared to the drawing.
The final test, of course, is to print and be sure that you do not have molten filament leaking out on the heat block and onto your print!
RE: Whole hotend rotates while trying to screw the nozzle in
Hey is the brass washer still working for you? I have 8 printers with nozzle X and it's just a merrygoround of leaks and replacement heatblocks
RE: Whole hotend rotates while trying to screw the nozzle in
me too, very poor design, if you undo the nozzle, in the near future you will be rebuilding your entire hotend, what a ball ache, happened more than once to me. the heatbreak can screw further in as the nozzle buts up against it
I avoid changing the nozzle unless I really have to because of issues like this.
RE: Whole hotend rotates while trying to screw the nozzle in
Yes, the brass washer works well. I have not had a leak since installing it. The short thread engagement in the heater block cannot tolerate many nozzle changes without stripping, so I bought a heater block and heat break for each nozzle I use. I am looking forward to the MK4 with the Nextruder to eliminate leaks entirely. However, the Nextruder V6 adapter will create the same problem with thread length if using hardened nozzles.