Posts made by stienfromarden

so... i was going to swap the pt1000 wiring and touched the connector and suddenly it popped back to around the same temp as the rest... guess it was still a sort of loose wire...

thanks anyway

I am currently printing a chair, with a triple heat zone pellet extruder, all diy and controlled by a duet wifi2.

While starting up today, I noticed heat zone 3 was 12 degrees c off from the rest (1 & 2 where at 18c and the last heater was at 30, while heaters are not on and at room temp...)

I was in a hurry and thought let's see what happens and started the print... now I get some weird spikes at this particular heater... I had some loose cables before on another pt1000 and I know how that looks like (jumping from 0 to 2000c all the time) these deviations are different.. I have been using these pt1000 for over a year and I don't know what going on..

I have no clue where this can come from all of a sudden, anybody here experienced the same issue? See printscreen for clarification:

• Stijn

Thanks guys will give this a go tomorrow!

@JustinCase said in Multiple extruder motors simultaneously movement:

agitator

I have multiple steppers laying around, and some control over the speed would be nice

just an agitator yes. It isn't tied to the walls of the hopper, just there to stir everything up and push it to the orifice of the pellet extruder, could be turned on permanently after power up

For a pellet extruder, I have a second screw, pushing the pellets towards the main barrel and screw, Sometimes pellets get stuck in the hopper, this motor and screw will prevent this. The thing is I actually need it to always run after startup or to run when the extruder motor is turning.

Anybody here knows how to pull this off?

The start is not in there since it included the password... as far as the interpolation this works, I'll clean it up later, I am more busy with the heaters right now...

I got it kind of figured out, all heaters where in bang bang mode, didn't know how to turn that off....

I am not at the point of turning on all 3 heaters but I am also a bit afraid that the fluctuations might occur...

config file is attached in the first post.

I have almost finished building a pellet extruder for my 3d printer. It uses a 16mm screw and barrel with 3x240watt band heaters with a PT1000 sensor for temperature monitoring.

The outer diameter of the barrel is 35mm so there is a LOT of mass that needs to be heated. I am trying now to configure the PID parameters for the heaters but I just can not get it to work. I ran it lots of times, put in the results but still when I put the heater on to let's say 100C it overshoots by 15C and after that keeps fluctuating around the desired temperatur.

Anybody out here that can help me out? The PT1000 sensors aren't mounted the best possible way and I already ordered some isolation material to wrap the whole extruder in. But still I think it should also work like this....

See files attached

config (5).g

@dc42 said in Thermocouple problems:

@stienfromarden said in Thermocouple problems:

Is it an option te reuse the type j termocouple wires to extend the pt1000? just for about 20cm to reach the termination box? these wires are steel braided and can handle some high temperature..

Doing so will introduce a small temperature error. The size of that error will depend on the temperature difference between the two ends of that thermocouple wire. It may be insignificant, I haven't done the sums.

@dc42 thank you very much for the answer!

I did not now if these:

https://docs.rs-online.com/f7e6/0900766b8155404c.pdf

pt1000's were ok I don't know much about them but I hope it will work! Can't wait to power up the extruder an PRINT!

Is it an option te reuse the type j termocouple wires to extend the pt1000? just for about 20cm to reach the termination box? these wires are steel braided and can handle some high temperature..

I decided to just go with some pt1000 sensors:

https://nl.rs-online.com/web/p/platinum-resistance-temperature-sensors/1005972/

It's just too much trouble for a bit faster response time and accuracy.... extending the cables of the tc will cost more then switching to pt1000 sensors

Ok, I ordered these, will test them asap thanks

https://nl.rs-online.com/web/p/platinum-resistance-temperature-sensors/4573596?cm_mmc=NL-PLA-DS3A--google--PLA_NL_NL_Automation_%26_Control_Gear_Whoop--(NL:Whoop%21)+Platinum+Resistance+Temperature+Sensors--4573596&matchtype=&aud-826607888547:pla-337006323533&gclid=CjwKCAiA-f78BRBbEiwATKRRBHKjwc9eOcrE-EOTubGatWMWtCC69Qty15oUHY3XsNwbDANqlNHivhoCDqUQAvD_BwE&gclsrc=aw.ds

Will this pt1000 be possible to use with the duet wifi 2 directly mounted under a heater bend of pellet extruder?

ok there are no voltage drops at the beginning and end of the cable, I meassure 2,98 at both sides.

I figured out that moving the connections a little changes the reading, sometimes to the ambient temperature, I will receive some plugs to fit the daughterboard and duet, maybe this will help some!

What could be an option is to extend the thermocouple wires... but that is an expensive guess....

https://nl.rs-online.com/web/p/thermocouple-extension-wire/3706228/

The SPI signal could be the problem, but I am reading 10 meter maximum and I run 6 meter...

I don't think EMI is the problem because when I tested the thermocouples on the daughterboard directly on the Duet, although the tc was running through a lot of wires in the electronicsbox there wasn't any EMI. Or maybe it is in the 10 wire cable in between the daughterboard and duet..

BTW I also use the breakout board, could that also be an issue?

The other lines are, the stepper, fans and the 230volt heater bands. BUT these are all turned off while I was testing. It would be surprising if this causes EMI. I also did a test while unplugging the fans and plugging them in, but that didn't give any changes, so I think EMI is out of the question.

The voltage drop is something I will check out tomorrow, that will clear up a lot I think.

Thanks!