chamber heater alarms out expecting 1.8C/sec

oozeBot

@rexx What that is saying is that the measured temp actually decreased between polling. Perhaps that is due to your doors being open? I guess I was thinking momentarily opening the doors, not leaving them open.

So your current M307 is?

M307 H0 B1 C7200 D50 R0.01

rexx

@oozebot
yes but the 5 sec is not enough time to get to the thermistor
my pannels are off for testing once i get heats on long enough i will close them but i can still touch the heater itself warm but not hot so the termocouple wont see it either if my hand cant tell either will the termistor 8" away

rexx

@oozebot
i feel a hair dryer on a relay to the thermocouple could keep the heater alarms happy "lol not doing jk"

oozeBot

@rexx Something that may have helped us out is that the probe for the chamber heater is mounted on our toolheads. We park it dead center of the build plate, a few mm up on Z, when preheating our machines.

rexx

@oozebot
Probe is in the chamber itself on the circulating side of the air return (OEM STRATASYS 768 chamber) so the probe will only get heat after the entire chamber starts to rise its not a small printer at all

oozeBot

@rexx I'm afraid you are running up against the same issue we were able to overcome where the probe simply can't dip negative without causing a heater fault. Adding @dc42 for awareness.

oozeBot

@rexx said in chamber heater alarms out expecting 1.8C/sec:

Heater 0 fault: temperature rising too slowly: expected 0.76°C/sec measured -0.01°C/sec

I'm curious about this though. I would not have anticipated the "expected 0.76c/sec" with that M307. We were seeing errors like:

Error: Heater 0 fault: temperature rising too slowly: expected -0.00°C/sec measured -0.01°C/sec

do you have M141 set?

https://duet3d.dozuki.com/Wiki/M141

rexx

@oozebot of course it would be to easy to set and forget a simple heater why not use a time out call for heat only 2 min it should see a increase in temp 5 min should continue to see increases and 15 min the target must have been reached once to stay on
add a temprature deviaton of 15% for opening the door

its rocket science apparently but i thank you for your time today and efforts and shares in relation

as for the probe on your head i cannot do this as i have a peltier cooling plate on the heat break to disable heat creeps but was not on during this testing

rexx

@oozebot
M141 H0 this is all 141 under chamber config.g

rexx

@oozebot

under temps are going to happen: the static no fan ambient temp is hotter than circulating fan air so when the chamber fans go on the temps will go down until heats are seen everytime you apply chamber on from ambient temps i would expect a dip first it is naturally going to happen
if the probe is too close to the heater you will not accheve the real setpoint where it is needed calling off the heats to soon

oozeBot

@rexx I agree - its frustrating. However, I do understand why the fault tolerances were tightened they way they were. It just doesn't translate well to chamber heaters.

You know, I shouldn't even suggest this, but.. it would be possible control your heater's SSR through daemon.g and just toggle it on and off based on a set temp. That is not a good long term solution, and bypasses all protection, but.. it would work.

rexx

@oozebot
this is likley what i need as the chamber has thermal snaps eveywhere OEM so is partially safe from over temps the thing is it would be nice to catch a latched SSR on over time out this is all i wanted the duet to do

heater timed out......5,10,15 min to easy i guess... i will try to learn about this DAEMON.G thanks again!

super cheers for the help here

rexx

the other option that would really bite but is possible put the chamber heats on a sepeperate outboard controller and call it a day and delete all chamber crap from the configs i feel this is a key part to duet and am shocked this is still a loose end for such a key component i wish i would have know before hand and just built it this way instead perhaps......

but i was pretty sure this would have not been an issue i was wrong! rolling in my hand a T-100 1/2 din TCcontroller wishing i would have not bought the j type daughter board to keep the oem thermocouple then was the clear choice

there is allways more than one way to skin a cat! where to start is again the question...kick this one down the road abit longer or just replace it!