Blips in Temperature - Not seen before Fireware 3.5.0  

Re: Blips in Temperature - Not seen before Fireware 3.5.0

Not using 3.5.0 but maybe a PID calibration might help?

Re: Blips in Temperature - Not seen before Fireware 3.5.0

no issues here.

Re: Blips in Temperature - Not seen before Fireware 3.5.0

I experienced the same issue, on my first print today after upgrade of the firmware. I saw two dips of about 10°C about 15min apart. Don't know if they happen regularily, since I did not closely watch the print ...

Re: Blips in Temperature - Not seen before Fireware 3.5.0

I was just about to post again.. Just had this:

The temperature dropped well below a level where it would be able to print.. But the object I am printing does not have any scars or indication of a problem.. So i assume the printer stopped whilst it did this....

Re: Blips in Temperature - Not seen before Fireware 3.5.0

Same here. Several hotend temp dips during 8+ hour prints over the weekend on 3.5.0. Not seen before.

Re: Blips in Temperature - Not seen before Fireware 3.5.0

I had just 2 blips in succession and I noticed something, they are EXACTLY the same shape. This clearly is software rather than some kind of electrical connection issue, as the temperature drops to exactyl 200 degrees in both cases and the recovery time is the same (with the little dip back in temperature as it comes back up).. So hopefully Prusa are aware of this and will have a fix soon

Re: Blips in Temperature - Not seen before Fireware 3.5.0

Are you using the MMU? Perhaps it's some goofiness there. It sets speeds up and down if you're using TPU, sets k-factor up and down as you go.

Even if it's not SET low, it could be ramming filament in quickly on the change, which sucks some heat out.

If not, well then, you got me. 😛

Re: Blips in Temperature - Not seen before Fireware 3.5.0

Are you using the MMU? Perhaps it's some goofiness there. It sets speeds up and down if you're using TPU, sets k-factor up and down as you go.

Even if it's not SET low, it could be ramming filament in quickly on the change, which sucks some heat out.

If not, well then, you got me. 😛

Nope.. just a standard Mk3

Re: Blips in Temperature - Not seen before Fireware 3.5.0

Mine blips have the same shape as jweavers, and no, also standard (pre built) MK3.

And, no, I did not run a additional PID calibration. Since, clearly, the parameters of the temperature controller is well able to keep the temperature, and there is no evidence (or even possibility) that a simple PID-Controler could be the cause for such a behavior.

Re: Blips in Temperature - Not seen before Fireware 3.5.0

I am experiencing the same blips that are shaped as posted earlier except one of them was much more drastic (dropped from 213 to 190 and then returned back to 213). I upgraded to 3.5 fw today, and I suspect it's related based on posts above. I had major swings in hot end temps weeks ago and ended up replacing the thermistor, so I thought this was another issue related to that. I am glad to see it's likely sw related.

Re: Blips in Temperature - Not seen before Fireware 3.5.0

Again a dip, this time I took a screen shot.

Re: Blips in Temperature - Not seen before Fireware 3.5.0

Mine blips have the same shape as jweavers, and no, also standard (pre built) MK3.

And, no, I did not run a additional PID calibration. Since, clearly, the parameters of the temperature controller is well able to keep the temperature, and there is no evidence (or even possibility) that a simple PID-Controler could be the cause for such a behavior.

It would seem, for the sake of completeness, that it would make sense to check the PID values and see if they are at least sensible. This can be done over a serial connection without altering their values: I believe M301 will do this - report the initial values, but I haven't confirmed.

Interestingly, there's also a "W" term, which is a limit on the I term, preventing integral windup. That's just the kinda thing which will make a PID loop got o an extreme and sit there for a long time before recovering.

Re: Blips in Temperature - Not seen before Fireware 3.5.0

Hello guys,

I've seen today also the same "issue". Not affecting the print but it would be interesting to know from what it's caused.
Never seen before firmware upgrade 3.5.0, runing with octopi 0.15.1 and Octoprint 1.3.10.
Approx. 10°C drop down and every 30 min.

...point to follow !

I wish you a good evening,
Ludovic

Re: Blips in Temperature - Not seen before Fireware 3.5.0

Does the same to me, but I watched out that this is caused by the fan speed increase. Maybe bridges or top layers, but behind every of these blips there is a shorttime fan speed increase which causes sudden temp. drop. Especially with the new R3 design of extruder, where the air goes from fan directly on the nozle and heater block. That design is not fortunate, it also causes sometimes thermal runaway error, espcially while printing first layers close to the heated bed.

Re: Blips in Temperature - Not seen before Fireware 3.5.0

Funny, I just started to use Octoprint again yesterday and noticed a -10c dip during a print as well. I ran Octoprint when using a much older firmware version and never noticed an issue before.

Re: Blips in Temperature - Not seen before Fireware 3.5.0

I am having problems as well. I had a failed print (clog) cleared the clog, started it again, and sure enough it clogged again. Looked and the temperature was swinging by about 10 degrees.
Started a new print (with different filament) same thing. I also noticed the "pause while heating issue)
But, I have been running 3.50 for a week or so now with no problems.

Did anyone try a firmware downgrade?

I am also wondering in my case if the thermistor isn't working properly. (did a nozzle change recently which might have stretched it)

Thanks.

Re: Blips in Temperature - Not seen before Fireware 3.5.0

I have had all the issues listed above and finally I downgrade to 3.4.1. That was the last stable release ive used. I gave up on 3.5.0 final. I wasted 1 roll of filament. My advice is to downgrade to 3.4.1 and start printing again.

Re: Blips in Temperature - Not seen before Fireware 3.5.0

Again I had at least 2 dips, definitely not fan related (was on constant RPMs, and on).

Re: Blips in Temperature - Not seen before Fireware 3.5.0

Are you sure about the constant fan speed? I tried to look for M106 codes in gcode and found several in my testing one. In my case it is definitelly related to this. I found, that it is happening mostly while printing PETG. Looked at Slic3r settings for PETG and there is "Auto Cooling" function there, which increases the fan speed in case that layer print time is below 20 seconds (small objects). That is exactly how the printer is acting, increasing fan speed for a couple of seconds.
I am not sure if this feature was always set this way, maybe this is not an issue of new firmware, but new default setting of Slic3r.
Can somebody check on his gcode, during its print the temperature dips happend?