Why do the printers I get always end up being the ones with terrible filament stalls and grinding extruders?
The Repman didn’t have the greatest hot-end but at least it did have a PEEK heat barrier in the barrel. (The PTFE inset was more of a problem)
The ThingOMatic was unusable until I replaced the extruder and added 2 fans + 3 heat spreaders above the hot end.
It had to go because of the terribly designed heated belt drive, X and Y stages.
The Makibox has a better XY-stage and I installed a new extruder but just 1 fan and 1 heat spreader didn’t solve the hotend filament stall issue at all.
Just a dumb question, why on earth do you keep doing same mistakes over and over. There are many printers out there that have all this solved. First that comes to my mind is mendel90 from @nop_head This is IMHO the best printer for the money if you don’t mind it comes in a kit.
@Matej_Rozman when asking about a reliable printer on the Ultimaker came up.
The Ultimaker is where I got my advise on how to fix the filament stall issues from and prints I had someone else do on one at Easterhegg showed such issues. So it can’t be as reliable as I would have wanted it to be.
In fact, I have seen photos of great prints from every 3d printer out there. So it’s possible to do so with each and every one of them. The recommed Ultimaker was way out of budget.
Nobody mentioned a Mendel90 at all. So that one was not considered.
Collecting the parts for a Reprap was not an option. I find their development- and patch process to be rediculusly intransparent and will not have any Mendel, Darwin or Huxley in my house because I would end up reading their forum for month to hunt for bits of information that should have been on the table before deciding on it. (Known issues in a bug tracker? Known roadmap to see when your device is stil in development and when a finished and released design will be out of service? Patches with obvious explanation or scientific test reports proving the improved performance of the fixed part instead of random “improvements” incompatible with each other?)
I did expect the Makibox extruder and host-software to fail, so I replaced both.
It does have a mounting port and solder pads for a Raspberry Pi with Wifi after it’s power supply after all.
The hot-end looked better designed then many others out there and the initial prints seemed to prove that.
I had my doupts about the X/Y stage but it performs surprisingly well and fast. Should it not, it would have been within my abilities to fix that.
The hotend is the one part I have to trust.
So: What 1.75mm, bowden capable hot-end is perfectly reliable any WHY?
I’d have no problem exchanging mine but I won’t try any random hotend just because one person has no problems with it (that’s the case for all hotends) without being able to explanain why it is a better design.
(Thermal barrier that needs no PTFE inset?
Active cooling to keep the heat from travelling upwards?
Nozzle that can’t clog for some explainable reason?)
The RepRapPro hotend I use is pretty damn basic and I’ve never ever had any issues with it… It is not crap quality at all - but the design is almost too basic to be true…
Makes me wonder when lots of people have trouble with hot ends
is it so badly machined that it has gaps or is very rough inside or misaligned etc?
is there anything else you could look at before blaming the hot end design? Might be printing too fast, too cold, too hot, crap filament, extruder / filament drive problems? Someone yesterday had retracts at 2.5mm and restarts (un-retrsct) set to 1.5mm…
In that case, on small details, the filament could easily end up backing 10-20mm up in the hot end, doing that constantly is NOT a good way to run a printer!
E3d are very high quality machined hot ends, they have a good track record and, like the ultinaker, there will be lots of posts of people having problems… This is because they know they can get help online… This is because there are a HUGE number of people using the same product… You might find 1 in 1000 bots has a certain issue, that’s quite a few ultimakers… For a smaller company that’s only sold 1000 bots there would only be one user reporting that problem (if any). I really think that’s why there would be a lot of posts about problems with ultimakers… Because there’s a lot of ultimakers!
lots of other people with the same issue.
Retraction is deactivated.
The shape of the filament after failure indicates that it heated up and expanded above the hot zone, thus increasing friction above anything any extruder could overcome…
Manual pushing and manual temperature observation as well as numerous observations of others have confirmed that to be the issue.
The temperature was increased from 190°C to 219°C when discussing the issue with the manufacturer. I conducted tests with 190-230°C and and confirmed too much general friction at 190°C.
I tested the factory supplied settings as well as faster(cooler filament) and slower speeds(more torque) and a few other factors.
How heavy and long is the E3D hotend and does it require a fan for that upper part?
What kind of connector does it have at the top?
(Frankly it does look too heavy for the Makibox XY-stage.)
Yep, the only downside to E3D is it size and would look really huge in such compact size like makibox. The fan for cooling cold end is mandatory and is part of what makes this hotend perform as it does.
If I were in your shoes, id look into some smaller hotend solution, like maybe genuine J-head. Its PTFE and PEEK construction doesent mean its outdated or something bad, its just constucted in a way to work and giving the number of people using this hotend over the world, Id reckon it has really good run. I personally had only good expiriences with J-head, switched over to E3D only to be able to print PC and high temp materials that require over 260 degrees when extruding.
The other hotend I really have high hopes is Hexagon hotend from reprapdiscount. I have one but haven had time to play with yet. It has some very unique features and I belive it has potential to be god&reliable hotend. Maybe @Reprapdiscount_Elvir can provide us some details about this hotend?
I had a PTFE lining in the Thing-o-Matic and it disn’t like filament that where 0.0xmm larger. But a large PTFE linint should not have this issue. (Filament was way less accurate back then)
The PEEK barrier in my Repman worked fine as a heat barrier. So that’s a sound design.
I think someone else already did a conversion of a Makibox to a J-Head. I shall look that up.
Maybe see if you can insulate the hot part of the hot end from the rest of the barrel, you’ve no doubt seen people with kapton and (I’m going to say cotton but check up on this, it may be something else) around the heater block, the aim being to keep the barrel as cool as possible… Convection from such a large heater block can cause overheating in the barrel… I’ve never personally done this but some people have to!
The barrel is metal and screwed into the hot zone.
Aparently the same problem as the Thing-o-Matic hotend had, except it’s thinner, so I can’t easily add heat-spreaders and fans. (On the ToM I added cicular heat spreaders and 2 fans. Since the battel is inside a square space the fans managed to make the air move downward instead of passing hot air upwards in addition to the heat transmission in the metal itself. It did help quite a lot.)
These new all-metal hotends like the E3D seem to include cooling fins and a fan on the upper part of that same barrel.
I’ll try to emulate that using very small and very large washers. I’ll also move my fan down to blow across these.
Maybe a paper-washer between the heater block and the nut on top of it could help too.
I’ve seen people use nuts and large washers to emulate e3d, don’t know how well it works…
Do you have access to many tools? Some 20-30mm diameter aluminum bar drilled up the guts and cut into discs that fit tightly on the barrel would be great… The RRP hot end i have has an 8mm bar which the barrel passes through with a heatsink and fan attached, it works well, Google the RepRapPro hot end and see if the heatsink block looks like something easy that might help your situation… Its not at all intricate or highly engineered but it works well for me
It will be hard to get a very thick yet soft (easy to machine AlMgSPb) aluminium tube but I think I could drill it, then machine fins and cut threads to screw it into the heather-block instead of the stainless steel rod.
But that is something to consider after my trial with washers today.
Aluminum is a good conductor, I think the heatsink block would be easy to knock up on a CNC, just 3 tapped holes in 8mm solid square bar, one for the hotend to pass through, two to mount the fan heatsink… 2 more if you want to mount it the same was RepRapPro do but that’s probably not practical on your existing hotend…
But washes will be easier to try first let us know how u go!
Not sure if you have the same grades there as us but square bar is never good for machining IME - but because there’s only drilled and tapped holes this isn’t too bad
