DEF but both thermisters reporting OK in firmware

[morgandc]

Well, that didn't last long After a great first evening and night of printing, I now get DEF for my temps. According to the forums and the seemecnc website this is commonly a thermistor connection problem. HOWEVER, seemecnc.com tells us to turn on the printer and just prior to going to DEF read the values and one will be identified as the problem by showing either a negative value or a value of 300 c.https://seemecnc.zendesk.com/hc/en-us/a ... string=def

My temps are showing the following, which don't indicate an error. I have left message for both seemecnc (this morning via email) and late today (voice) with matterhackers with no replies yet... Any ideas? I have placed a heater in the room....just hoping.

NOZ: 13.7 fluke IR indiates around 22 c
BED: 23.5 fluke IR indicates around 22 c

-Dwight

PS I did use magnifiers (new toy) to look at both ends of the Noz thermister wires and they look good

[Xenocrates]

That nozzle temp is your problem. The printer will assume it's a fault if either one is below 18 degrees. This is configurable. My recomendation is to put a heater in the room, as this will improve print quality. However, you can also change the setting in the firmware for that, if it's infeasible for you to add a heater to the room.

[morgandc]

Ok, I just found a min. 18 setting in the configuration.h file in arduino. I am going to set that lower (10) and test. I think the thermistor is reading low. 18c is 55f and my room is running 70f right now.

#define MIN_DEFECT_TEMPERATURE 10

[morgandc]

No joy, 13.9c on the nozzle then def it goes. Is there a way to confirm the firmware change took place? I did an eeprom_clear that said successful, the uploaded the change and after a power cycle it still boots....

[moo77777]

Did you change the value for the correct printer? I initially had a problem there and iirc there is a MIN_DEFECT_TEMPERATURE for each of the 5 possible printers.

[morgandc]

Thanks! I didn't catch the flow of the configuration.h file, I just found the one that looked promising and changed it... Now to the next problem

[morgandc]

Argh!

Temp issue fixed, but now the calibration script tries to send the print head through the x axis tower!

1. re-downloaded the firmware, confirmed printer and motherboard settings and min temp and reuploaded. No help.
2. re-downloaded the calibration script, reran. same issue.
3. Put the temp back to 18, dry run same issue.
4. Matter control will let me move the print head around manually fine.
5. confirmed bed size is still 280mm and circular in Matter Control
6. tried to print something, bed starts to warm up, the nozzle doesn't move up much and then the printer says Heater Decoupled.
7. when trying to print the nozzle is not heating up per both firmware and IR temp. I think crashing the head into the tower a few times must have broken a wire/soldier joint for the heater cartridge. I will tear down the head to check this when I don't crash the head on calibration...

Issues:
A: The printer was carefully moved to update the firmware, now I can't calibrate without crashing into the x axis tower.
B: Heater decoupled? Is this because it isn't in the right heat range soon enough, or that the heater in the nozzle is now broken/disconnected? Bad thermister? Bad connection to Heating cartridge?

[moo77777]

Are you running the calibration with a cold hot end? I kept getting issues on the x-tap with I ran it at temp.

[morgandc]

Yes, cold. No power to heater, no recent print. (ran the unmodified version off of the SDCARD) with no USB connected).

[morgandc]

Well, I got through to MatterHackers tech support, and they immediately said check/plug the hot end plug better. They have had multiple reports of these symptoms. And sure enough, unplugging and plugging in the hot end better resolved the issue.

So all is working, now to figure out the nuances of printing PLA and extruder clicking.

[mhackney]

I'm still collecting data and conducting tests but it seems that the HE280 hot end needs to have a little more heat for PLA (maybe other filaments) as print speed increases. I have measured my nozzle and it is right on target with the set temperature. But, as I speed printing up from 35 mm/s to 50 mm/s - especially with rapid back & forth infill - I get occasional extruder clicks and filament starving. Raising the temperature 5°C to 200°C results in a good print at 50 mm/s with not extruder clicking or filament starving.

I mentioned this to JJ earlier today and hypothesized that maybe the design of the hotend reduces the effective melt zone (and preempt zone). I do not have this effect with an E3D V6 hotend, it pretty much extruders nicely at 195°C up to 80 mm/s.

[Noircogi]

My Max V3 is only my second printer. My other one is a replicator dual. I calibrated my hotend and bed temps using a high quality probe, but it seems to me for good filament feeding, I definitely need to run a bit higher temps for both PLA and ABS than I do on the replicator.

I've been using a bit more fan to compensate, even a low fan speed for ABS.

[skyjuice]

Well, I got through to MatterHackers tech support, and they immediately said check/plug the hot end plug better. They have had multiple reports of these symptoms. And sure enough, unplugging and plugging in the hot end better resolved the issue.

So all is working, now to figure out the nuances of printing PLA and extruder clicking.

Sorry for sounding so new, but I am. What is the "hot end plug"? I have the SAME issues here and cannot figure it out and have tried numerous times, unsuccessfully to contact support.

[AwesometroN]

Sorry for sounding so new, but I am. What is the "hot end plug"? I have the SAME issues here and cannot figure it out and have tried numerous times, unsuccessfully to contact support.

This is the hot end plug. Sorry for any bad formatting I'm sending this on my phone.

[skyjuice]

Sorry for sounding so new, but I am. What is the "hot end plug"? I have the SAME issues here and cannot figure it out and have tried numerous times, unsuccessfully to contact support.

This is the hot end plug. Sorry for any bad formatting I'm sending this on my phone.

Thanks! I actually just found the problem with my machine (V3) and why the bed was dropping in temp then both therms reading DEF. The whole time, the bed thermistor was touching just a sliver of the metal ringed hole the glass bulb sticks out of. I put a piece of Kapton tape down over the hole, popped a hole in the tape and that prevents any contact with the surface and the thermistor...and now I am printing better than ever! That should be something they tell you in the instructions, but I guess that's part of being open-sourced.

[skyjuice]

I printed this harness/retainer clip and it holds the plug nice and snug!

print the tight fit whip clip.

http://repables.com/r/808/