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E1 Heating Failed
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Description

.91 marlin firmware & Cura 3.6.5
Printing a dual PLA print, after an hour and a half I started to notice E1 was taking longer and longer to heat up. At first, it would pause for 5-10 seconds to heat up before E1 would start printing. I watched it the next few nozzle transfers and noticed the temp would start to drop after the nozzle transfer then it would start climbing ever so slowly until minutes later I received the E1 Heating Failure.

Only changes to the print profiles made were 15deg increase in printing temp and printing infill before shell.

Event Timeline

eBeardslee added a comment.EditedFeb 21 2019, 11:56 AM

So I turned the printer off and on again. Printed the same file without any modifications. The print is now further than the previous failed print but it did have some weird temp fluctuations and one or two pauses earlier on in the print. At one point, both nozzles were dramatically under temp. Not to mention neither nozzle indicated the proper idle temp. Shortly after I caught E1 at 250deg when it was supposed to be idling at 175. After these weird anomalies the printer resumed as normal.

I went down and tested the thermistor and heater cartridge on E1 and E2 for this printer to see if this was a hardware issue. Both of the heater cartridges were well within range (roughly 13 ohms on both extruders), thermistor wiring was throwing odd readings (between 190k ohms and 298k ohms). With readings like this on the thermistor you would expect to have an inaccurate reading on LCD but it was showing room temp so we weren't able to pin this down as being definitively hardware related. There is another test going on the printer now with some adjusted settings to see if that resolves this issue.

oliver added subscribers: marcio, oliver.EditedFeb 22 2019, 3:19 PM

@Galadriel and @eBeardslee The way I heard it described to me is that marlin uses a table of values to interpolate the temperature with a given resistance, maybe @marcio can correct on this if I'm wrong. It could be its hitting that lower limit and thinking its room temperature. A 298k Ohm measurement is indicating that the thermistor is 3.8 degrees celcius and a 190k Ohm resistance is 12.20 degrees Celcius. These values were obtained using the Stein-Hart equation.

If those values are accurate, I would defiantly recommend trying to swap out those thermistors to see if you can get any better results.

@oliver @reprapperMC after this ticket I started to use Angie's new polymaker profile and was able to print with no pauses due to slow heating or E1 Heating Failures (only got two prints in). The printer is currently on it's way to Mountain for inspection.

west added a subscriber: west.Feb 25 2019, 2:13 PM

I tested the thermistor and it is reading ~100 k ohms. No crazy fluctuation. @eBeardslee can you post the gcode you were using?

@west

Was this determined as faulty hardware? Can this ticket be closed as an isolated event?

@EricNugent this seems to be resolved. I believe it had something to do with profiles and the fan being too high and blowing on the nozzle.

EricNugent closed this task as Resolved.Mar 22 2019, 8:49 AM
EricNugent claimed this task.

@eBeardslee sounds good. Closing it out for now.