Heater fault going from standby to active
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I have increased the heater fault time (M570) from 5 sec to 6 sec to hopefully catch the heater fault although I would prefer not to tweak that safety feature over every aspect of the heater behaviour when only that one tiny aspect of the heater operation is causing the problem. I will experiment with inserting an M570 at the beginning of a tool change and revert to the default 5 seconds at the end of the tool change. I am not sure if that will work or if I have to do it in tpostx.g
I have inserted an M116 in the resume.g macro to hopefully force the printer to wait, after 'resume' is selected, for the temperature to come up to spec. (not tested yet but if somebody could post their resume.g file that would be great)
That still leaves me with the issue of the tool pickup not completing if a heater fault (and presumably anything that raises a fault) happens just before a tool is mounted. I do not have a clue how to tackle that one.
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An update: I have increased heater fault time to 10 seconds without any change. I still get the heater fault. For some reason the fault does not happen at the first transition from standby to active but it happens on the second transition.
I am still looking for input on how to complete the tool change if the temperature fault happens after the toolchange has started but before the tool is mounted.
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@jens55 What exactly is the heater fault you are getting? Can you post the text of the error message?
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@gloomyandy, the actual error message doesn't appear on the console log but it was something like "the nozzle is heating too slow, 1.09C/sec expected, 0.38C/sec measured (those are the actual figures that I noted)
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Based on there being no change in behaviour with a longer heater fault timeout (going from 5 seconds to 10 seconds), there must be different code that tests for rate of change and is not affected by the timeout parameter. Maybe I have to tweak one of the heater parameters ?
I am hoping for some input from @dc42 .... -
What are the tuned heater parameters you're getting?
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@Phaedrux
; Heater model parameters
M307 H0 R0.684 K0.420:0.000 D3.42 E1.35 S1.00 B0
M307 H1 R3.388 K0.453:0.317 D7.40 E1.35 S1.00 B0 V23.2
M307 H2 R3.245 K0.703:0.052 D9.61 E1.35 S1.00 B0 V23.6
M307 H3 R2.771 K0.541:0.088 D8.68 E1.35 S1.00 B0 V23.2
M307 H4 R2.245 K0.600:0.001 D10.06 E1.35 S1.00 B0 V24.0 -
@jens55 Which heater gives the fault or is it all of them? Assuming heater 0 is the bed, and heaters 1 to 4 are the tools, there is a fair difference in the tuning models. So knowing which heater gives the fault might be useful to know. For example, if it's heater 1, then a slight tweak to the dead time might be a solution.
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@deckingman, I was using H2 and H3. I am about 90% sure that H3 was the one that was faulting. I did however have a similar problem with another printer that heated to 150C, waited for a bit and then went to printing temperature. I did not diagnose that issue in detail so I am only mentioning it as a point of interest.
I can try increasing the D parameter and see what happens. -
I have made an interesting observation. I didn't think about it at the time but my nozzle blocks are copper and not aluminum. This seems to cause a lot of over and undershoot (up to 10C!) because of the extra thermal mass and might very well have caused the issue. I have not had an opportunity to change the dead time for the heaters as things are not faulting at the moment <shrug>
The second issue has not been addressed but it only happens on tool changes and it could be argued that this should be addressed in the Jubilee forum. I suppose that the tool changing macros might be at fault but IMHO, if a fault is raised, then fixed and the printer is told to resume, it should really know to finish what it was doing when the fault was raised. Instead the printer thinks the previous operation (mounting the tool) was completed and no attempt is made to finish mounting the tool.
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@jens55 Looking back through some historical configuration files that I have, I see that I used heater fault detection of 10 degrees and 30 seconds when I had a hot end with two heat zones (so two heaters and two sensors). My memory fails me somewhat but I seem to recal that this dual zone configuration was causing heater faults which is why I set wider tollerances. I decided that, because of the way the heaters were installed, it was practically impossible for one to fall out. So if a sensor failed such that the heater was permanently on, the temperature rise would be constrained by the thermal inertia if the block. Looking at the temperature rise time I also concluded that after 30 seconds at full power, the temperature would never reach dangerous levels so those wider tollerances would not be unsafe.
So my point is that rather than using the default heater fault tolerances as some sort of Gospel setting that should never be deviated from, do the calculations for your own hot ends and see if a dangerously high temperature could be attained after a longer time period than the default.
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@deckingman, thank you. I have my fault detection set at 15 degrees. I did increase it to 15 seconds as well but since that did nothing, I went back to the default setting. I will play with both of those and dead time if the problem should return.
