Issues with J-head V6 Hotend

[jreyes]

Rostock max v2
J-head V6 Hotend 1.75mm
Nozzle : 125
Bed: 99
ABS

I been printing fine until yesterday I notice it wasn't printing well. I print about 60 hours or more into it and was working great. I clean Nozzle tip, Use thin wire to clean inside of it and check the wire . Seem like it having issue melting the abs filament. Is there some troubleshoot I can use or it is just the hotend need replacement. I try different filament but still does the same.

This is what I been printing and other things.

This is what happening. I try different filaments.

[Qdeathstar]

I could be wrong but there's no such thing as a j-head v6


There are j head hot ends, and an e3d v6 but I think what you have is a cheap Chinese clone.

I would lower your retraction, it might be jamming. I'd start with 1mm and then work up till you get rid of most of the stringing.

[geneb]

You're not wrong. There's no such thing as a "j-head v6." In fact, the only _real_ J-Heads come from hot-ends.com - any other source is virtually guaranteed to be selling vastly out of spec clones that aren't worth the postage.

g.

[Xenocrates]

Here's my thoughts on this:

1) You bought a fake. the J-head Mk 6/7/8/9 was never released, and the V6 likely indicates it's an E3D knock-off. Stay off Ebay/Amazon/Banggood for hotends, they are almost universally terrible.

2) There is likely clogging beyond just the immediate nozzle bore. You'll likely have to remove the nozzle and torch the entire interior clean, and possibly the heatbreak as well (I'm assuming it's an E3D clone at this point)

3) Your thermistor profile is wildly off. 125 should never melt ABS, or even PLA. It shouldn't even allow the printer to extrude, as it has a 150 minimum feed temperature (or there's a typo and you meant 225, which is a sane temperature).

[geneb]

I've actually got a Mk8.

g.

[jreyes]

Nozzle is set to 225 sorry I made mistake on my post. I will try the cleaning nozzle bore and see if it fix the issue.

Thanks

[Xenocrates]

I've actually got a Mk8.

g.

Should have said openly released. He wasn't openly distributing or selling then to avoid copycats, but the point stands that a mk6 is not something for people to commonly buy

[Mac The Knife]

Back on topic,,,, 225C, IMO, is on the low side for ABS. I'd try it again at 240C.

[jreyes]

I just got back from work. I will do some cleaning from inside.

Mac The Knife
I set it to 240C but I had the same issue. I did that to see if made a different but no

Printed on Friday. 225c 20 Infill

Printed on Saturday. 240 20 infill but it weak.

[Polygonhell]

Assuming you haven't made any setting changes, the most likely issue is something partially blocking the nozzle.
Most commonly this is an impurity that was in the plastic, or possibly some bur in the hotend itself that got dislodged.

You can sometimes fix these without having to disassemble, Nylon filament is commonly used for this, basically the procedure is to heat the hotend to say 240C insert the nylon by hand until it just extrudes, drop the temperature to the coldest point you can still pull it out (probably 150-180C ish) and pull the filament out of the hotend.
The idea is to trap the particulate or anything else in the filament and pull it out.
The harder way is to remove the nozzle, and inspect/clean manually

Without knowing exactly how the E3D clone you have is constructed it's hard to offer any other advise, I've seen them with and without PTFE liners, if it has a liner then if it's not correctly reporting temperature then the liner can get damaged and lead to the same thing.

[jreyes]

At the moment I haven't made no settings to the printer.

I try method I found online using Nylon Didn't work I disassemble it and put it jar and added actone for day. It clean inside. I put it back still have issues melting the filament. I remove hotend and install new one hotend. Look like it still have having issue melting the filament. Can it be wire or there not enough power feeding to the hotend.

[jreyes]

This is with other hotend. It only printed the layer you see and than it stop. I try it with different models stl but does the same. It one of those bad days for me.