Dual Extruder PID

Hi,
I have a custom 3d printer with a dual extruder. The problem is that I only can use the first one because the temperature of the second one is not enought estable. The extrutders are identic. Someone knows which can be the problem?

Extruder --> [www.hta3d.com]

Thanks

Noise on the thermistor line. If fan power or stepper wires are run next to thermistor wire it will drive the thermistor sense crazy.

uneven air flow over the heat sinks or too much air on the part

defective thermistor or heater

I have two identical printers with the same problem, in both extruder 1 works perfectly but the second one gets hot but does not stabilize. the temperature changes between 203 and 217 if I set a temperature of 210. Still, I have changed the thermistor and heater and I have the same problem.

Quote
JulenMG
I have two identical printers with the same problem, in both extruder 1 works perfectly but the second one gets hot but does not stabilize. the temperature changes between 203 and 217 if I set a temperature of 210. Still, I have changed the thermistor and heater and I have the same problem.

Are any fans on when it is doing this?

the extruder has 2 fans, the layer fan which is off, I tried to connect it to stabilize the temperature, but the same. The second is located in the extruder block to cool the filament before the material enters into the extruder. It is strange that it only affects one of the extruders

OK, I just found something I did not know that might apply.
There is a procedure for setting PIDs for both extruders and you may not have set the E1 PIDs
It does require that you have the EEPROM enabled.

Enter M301 E0, wait for it
then enter M301 E1 wait for it

I would expect the results to be pretty much the same?
If not, there is your problem.

To set them, from a room temp start, run M303 E0 C8 S210
then do M500 to save to EEPROM
Wait till they are room temp again and run M303 E1 C8 S210
then do M500 to save to EEPROM

then check with M301 again.

Let me know if that works

Edited 1 time(s). Last edit at 05/30/2020 01:27PM by ruggb.

Hi,
I'm not sure what's going on, but now, neither extruder works properly, the second one works better but it's not stable enough and the first one works worse. The temperature moves around 5 or 6 ° C up and down from the set temperature and the filament blocks the extruder.
I tried to reset all but i have the same problem with the first extruder. I don't understand what is happening.

It is a little hard to answer that "but now". That would indicate you changed something.
In order to specifically address your issue, you must be very descriptive about what you are seeing/doing.
When I suggest something it would be good to respond to it.

I am very familiar with jambs. All of mine happen for one of 3 reasons:
1. no fan on heat sink or fan misdirected.
2. heat on and no filament being extruded for an extended time.
3. Running temp too hot which overpowers the fan trying to keep the heat sink cool.

I am also very familiar with unstable temps. They happens for 3 reasons:
1. Fan misdirected or air reflecting off bed onto nozzle block.
2. PID not set correctly.
3. Noise on the thermistor line caused by the fan motor.

For the air issue, I had to reposition or slow down the fans.

I just had to readjust my PID for the extruder because the temperature was oscillating about 10°C
Somehow, I had put the wrong numbers in.

For noise, I had to twist my wires and separate them to prevent noise on the thermistor. I could see it on the temp graph.
Right now, I am seeing some noise on the temp graph but not enough to be concerned about.

Sorry for that "but now". I'm going to try to explain better the problems and the printer.
The printer have two extruders in the same block, that block have a fan foor cool it. bouth extruders are all metal. In the first extruder, the PID works perfect and only have +- 2º. In the second one I have make the PID ajustment 5 times and I have the same result.
In the case of the jambs, i'm not sure of what is happend because i only have done the PID ajustment and try to print a model that i have print before, with the same parametres.
This is the link to my printer: [www.hta3d.com]

So, it is a Chimera head.
which nozzle is the problem? The one with the high slot or low slot?
If you run the bad one without heating the good one, is it still bad?
Did you enter BOTH PIDs into the EEPROM? There isn't much diff so you could enter the same for both I suppose.
You could also try swapping the wires on the board so E1 is now E0 etc.
Does that change anything?

Both nozzles have the same size, 0.4.
In the printer I only can chage the extruder 1 PID and if has the good values for the PID, it works most of times and the extruder 2 do always the same. If I chage the extruders, the extruder 2 works perfect because have the PID an is the firstone wich don't work.
I think that the PLA is a bit wet because because the temperature of the extruder block is arroud 40ºC.

I am trying to get information from you about your hardware. You did not answer that.
Please note that I cannot put my eyes and hands on your system. Therefore, you must provide the info.
A longtime ago I posted something about multiple PIDs.
I do not have a dual extruder. So I cannot verify this. But apparently u have not verified it either.

IF there is a PID for each extruder, which logically makes sense, It sounds like you have not set the PID for E1.
Therefore, one would expect it to be running totally out of control.

NOW can u verify that u have run the 303 on E1 and saved the result with an M500?

Well, I have done a few more tests with different programs and using gcomands, I can't modify the settings, so I can't change the PID value of extruder 1, I'm not sure why it doesn't work and the two extruders are identical and with the The same PID should work.
The hardware is a mega arduino with Ramps 1.6+ and boulder extrusion .

You mean Bowden extrusion of course.

Maybe I shouldn't try to upgrade to a Chimera head, huh?

If swapping the hotends on the board so that E1 = E0 and E0 = E1 and E0 (which was E1) works normally that would say it is a PID problem. You could change it to bang-bang, and see if it works for both that way.

I assume you ran M303 E1 S210 C8 and got results. Did they look the same as M303 E0 S210 C8? Did you run M500 after you ran M303 E1?

I am out of ideas at this point.