I am running a custom built printer with a mini-rambo board and Marlin firmware. I sent M303 E-1 S80 and I am getting "Autotune failed: bad extruder number" I came up with this line after watching a few Y/t vids. According to what I've seen E-1 should represent the bed heater. Is there something I am doing wrong?

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If I haven’t screwed it up yet, I’m not thinking hard enough!

CoreXY, Titan Aero, Duet WiFi, custom design and build
Cartesian, E3D v6 hotend, Bondtech QR extruder, custom design and build

as long as you have your heated bed configured (and you have a thermister defined for the heated bed) that should work.

Edited 1 time(s). Last edit at 07/26/2019 12:57AM by Dust.

I have the thermistor defined for the heated bed. I am not sure what you mean “heated bed configured” the printer prints fine accept for an occasional “run away” error. Is there something else that needs to be “configured”?

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If I haven’t screwed it up yet, I’m not thinking hard enough!

CoreXY, Titan Aero, Duet WiFi, custom design and build
Cartesian, E3D v6 hotend, Bondtech QR extruder, custom design and build

Just the headted bed pin... which is normally automatically set when you choose a motherboard

oK, I am totally lost. What can I do to correct this (in specific terms please)?

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If I haven’t screwed it up yet, I’m not thinking hard enough!

CoreXY, Titan Aero, Duet WiFi, custom design and build
Cartesian, E3D v6 hotend, Bondtech QR extruder, custom design and build

Do you have the PIDTEMPBED configuration variable enabled in your configuration? If you don't, the bed will be configured to use bang-bang control instead of PID, so PID tuning doesn't make any sense.

Ahhhhhh..... ok. That gives me something to check. My guess is you hit it on the nose. Didn’t know about PIDBEDTEMP..


Thank you.

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If I haven’t screwed it up yet, I’m not thinking hard enough!

CoreXY, Titan Aero, Duet WiFi, custom design and build
Cartesian, E3D v6 hotend, Bondtech QR extruder, custom design and build

I could never get the PID Autotune to correctly function, the numbers it would give always gave me some kind of temperature error during 3D Printing.

Eventually decided to just use the Bang-bang with the Marlin defaults - This has never failed me for both the Nozzle and Bed.
This not be the best way though I cannot complain about the quality of my 3D Prints.

Though one day may try to again to Autotune them.

Edited 1 time(s). Last edit at 07/28/2019 11:37AM by Roberts_Clif.

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Computer Programmer / Electronics Technician

There have been some recent changes in the latest Marlin (bugfix-2.0.x) that should greatly improve PID performance, specially for the bed. You might want to try the latest bugfix-2.0.x sources.

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MMcLure
There have been some recent changes in the latest Marlin (bugfix-2.0.x) that should greatly improve PID performance, specially for the bed. You might want to try the latest bugfix-2.0.x sources.

Thank you ! an I do have Marlin 2.0 on my machines

Edited 1 time(s). Last edit at 07/29/2019 02:26PM by Roberts_Clif.

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Computer Programmer / Electronics Technician

The changes in question are only a few weeks old (and there was a commit last night that is also supposed to improve PID behavior). I haven't had any real problems with PID on the bed and hot end, either with the old code in 1.1.x or the new code in 2.0.x, although I think I see somewhat less oscillation around the setpoint at the beginning of a print with the code from a couple of weeks ago.

Edited 1 time(s). Last edit at 07/29/2019 05:28PM by MMcLure.

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MMcLure
Do you have the PIDTEMPBED configuration variable enabled in your configuration? If you don't, the bed will be configured to use bang-bang control instead of PID, so PID tuning doesn't make any sense.

YEP. That was my problem. Uncommitted it and the Autotune ran fine. Thank you very much

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If I haven’t screwed it up yet, I’m not thinking hard enough!

CoreXY, Titan Aero, Duet WiFi, custom design and build
Cartesian, E3D v6 hotend, Bondtech QR extruder, custom design and build