Mini and Dragon UHF hotend (again)
So I didn’t realize when it came to replace my hotend that the UHF dragon would fail the self test.
My question: Does it matter? It gets up to 100° C and then fails out. I assume because it doesn’t heat fast enough… can I just preheat it and let it sit til it gets to the right temp and trust that the temp stability will carry it through?
I can always order a regular Dragon. But obviously I’d like to make this work if possible.
RE: Mini and Dragon UHF hotend (again)
I did a PID calibration hoping that would make it happier and it definitely helped. But still getting a thermistor mismatch error. Not sure if they can be calibrated or how I can be assured the thermistor is working.
I ordered a regular Dragon but figure I’ll keep plugging away at this one if I can to get up and running.
RE: Mini and Dragon UHF hotend (again)
FWIW: I have two Minis with regular Dragon hotends. One has zero issues, the other one throws thermal anomaly warnings but ONLY on the initial filament load after turning it on. Once I've been through it, it'll print for days without issues, I can unload and reload no problem, etc, until I turn it off. I've replaced the thermistor twice, redid PiD, checked wires and board connectors. So at this point I'm quite confident that it's not a hardware issue. If it were, I'd expect to see thermal anomaly warnings pop up at other points, not just the very initial load.
My remedy to anvoid the initial warning: after turning the printer on, I manually heat the nozzle to 180 from the LCD menu before attempting a load. If I print PETG or ASA, I'll wait till it reaches 180 then manually raise it to 220 or so. This way I can get to a reasonable temperature without triggering a thermal analogy and can then execute the filament load procedure without issues.
Once through this, I can print normally, swap filament normally, let the printer cool down between prints, anyth8ng, no problem--as long as I don't turn it off.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
RE: Mini and Dragon UHF hotend (again)
@fuchsr I rolled back to 4.3.4 and no warning.
RE: Mini and Dragon UHF hotend (again)
Interesting. In all honesty, I'm not a huge fan of this thermal model. I applaud their desire to add more safety features. But there are just too many reports of perfectly fine working printers not passing the grade when there are how many reports of Prusa printers going up in flames? Exactly.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
RE: Mini and Dragon UHF hotend (again)
I just ordered a standard Prusa hotend. Going to stick it on and probably sell the Mini. What is the point of an open platform that isn't that open? I just placed an order for a Bambu since I just want my printer to work well.
RE: Mini and Dragon UHF hotend (again)
Lessons learned, for some reason, the Dragon is clogging up, maybe because it is the UHF version. Because the head is longer, the blower fan is too high, could just sub in a 75x75x15 fan to blow further down or reprint that mount to duct lower. The PID calibration helps,
RE: Mini and Dragon UHF hotend (again)
What is the point of an open platform that isn't that open? I just placed an order for a Bambu since I just want my printer to work well.
Well, if you think the Mini is not open, good luck with the Bambu 😏
In all fairness, it seems a bit farfetched to expect that a hardware vendor that allows its printers to be recognized heavily (from Revo to Dragon to Mosquito hotends, direct extruders, etc) could foresee every possible modification and have their firmware ready for every situation.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
RE: Mini and Dragon UHF hotend (again)
Well if they are both effectively closed off, then I will just go with the Bambu. In the end, the mini was just "okay" - it was never flat, so I had to do the silicone bed levelling mod. The extruder was mediocre, so I ended up putting a Bondtech on there, z-axis needed a bit of bracing, so I printed out and attached one.... I added a SuperPINDA, And the heat creep on the hotend meant I was looking for alternatives but the Dragon, a pretty popular choice, has been a nightmare.
Maybe I should have just bought an i3 or built a Voron, but at this point, I just want to get back to 3d printing and less fixing.
RE: Mini and Dragon UHF hotend (again)
I have the same problem and wondering if anyone found a workaround.
If I start preheating the printer, then stop and start a print everything is fine, if it fails and i start the print again when warm everything is fine but it would be nice to not have to do this.
RE: Mini and Dragon UHF hotend (again)
I was looking at replacing the Dragon hotend HF ceramic that i have currently installed as I get a nozzle heater error everytime I start a print. The quality of the prints are great so I was looking at getting the standard dragon hotend. Of the 2 that you have, do they use the ceramic or the aluminium heat block or is this a reason for the difference between you minis?
Thanks for your time!