I got the heater tuned just fine...used the guide that I found on the duet site. Now I have a much worse problem - every time I start a print, the Titan Aero that I'm using clogs in the throat/pipe or it bunches up in the hobbed gear. I tried several different temps and they all do the same thing. I followed the setup instructions on E3D's wiki page and it seemed like it all fit into place correctly, set the steps/mm (837) and then attached it to the printer (that's when I started having issues with the heater cuz it was brand new I guess) I finally got the heater working correctly (I thought) and now I can't even get one minute into any print job without it clogging up completely to the point that I have to disassemble it ...WTF am I doing wrong?? I dumped the TronXY motherboard cuz it kept having one issue after another, now the Duet2 is doing the same thing!! I am really about to give up on 3D printing all together...thousands of dollars invested and not one printer works the way its supposed to...

Every time I try to run M303 and autotune the heater, I get the message "No heater has been tuned yet" And it won't let me do anyting. The reason I'm trying to tune the heater is because I keep getting "Heater Fault, heater heating to slowly 0.7C/sec" I can't run any prints, it just errors out. I can't test my new Titan Extruder because it won't get hot enough to extrude PLA...I'm running a 24V 500 watt 20 amp Meanwell PSU and it seems to be working fine...it just seems like the power to the heater unit is fluctuating. I've replaced the heater and thermistor twice (once with older working ones and then with brand new E3D ones) and they are the correct voltage and wattage because I tested them on my LulzBot and they both worked fine. I'm stuck...what can I do to fix this heater issue??

Also - I had one other question...where do you set up the nozzle size? Whether its 0.4mm or 1.0mm? I cannot find it in the Duet2 controls anywhere??

I had to reduce it from 4000.00 steps per mm to 450 steps per mm then the distance checked out with a caliper...5mm down=5mm Thanks for your help!

And thank you, that link did help in figuring out the direction of the axes and the correct movement...

Ok...I have them all homing correctly, now the Z axis is stepping way to much - when I tell it to go 25mm it goes more than halfway down and the Z_Max is 400mm not 50mm???

Whatever that "G1 Z5 F6000 S2 ; lift Z relative to current position" does, its what causes the up and down problem with my motors...I removed that line and they all home correctly now except Z which is just reversed...how do I reverse the z stepper in the config files?

; homex.g
; called to home the X axis
;
; generated by RepRapFirmware Configuration Tool v2 on Mon Dec 24 2018 00:06:08 GMT-0800 (Pacific Standard Time)
G91 ; relative positioning
G1 S1 X-335 F1800 ; move quickly to X axis endstop and stop there (first pass)
G1 X5 F6000 ; go back a few mm
G1 S1 X-335 F360 ; move slowly to X axis endstop once more (second pass)
G90 ; absolute positioning

; homey.g
; called to home the Y axis
;
; generated by RepRapFirmware Configuration Tool v2 on Mon Dec 24 2018 00:06:08 GMT-0800 (Pacific Standard Time)
G91 ; relative positioning
G1 S1 Y-335 F1800 ; move quickly to Y axis endstop and stop there (first pass)
G1 Y5 F6000 ; go back a few mm
G1 S1 Y-335 F360 ; move slowly to Y axis endstop once more (second pass)
G90 ; absolute positioning

; homez.g
; called to home the Z axis
;
; generated by RepRapFirmware Configuration Tool v2 on Mon Dec 24 2018 00:06:08 GMT-0800 (Pacific Standard Time)
G91 ; relative positioning
G1 Z5 F6000 S2 ; lift Z relative to current position
G1 S1 Z-405 F1800 ; move Z down until the endstop is triggered
G92 Z0 ; set Z position to axis minimum (you may want to adjust this)

; Uncomment the following lines to lift Z after probing
;G91 ; relative positioning
;G1 S2 Z5 F100 ; lift Z relative to current position
;G90 ; absolute positioning

Yes...X and Y both home correctly now, its just Z that still has an issue (its 2 Z motors in series, by the way) When I home Z it starts to go up, maybe 10 or 15 mm then it reverses and goes all the way down until it hits the top of the motors...And I tried substituting all the codes in the CoreXY setup guide and most of them made it worse...I removed all the references to Z in the two homex.g and homey.g files and that seemed to fix those axes...but Z is still a mess. I remember in marlin, for my CoreXY I had to reverse Z motor in the Config.h file even with the CoreXY mode turned on...

@dc42 It was 2.01, I realized I had to install 2.02 RC2 first...

So that's not what's causing the "homing" issue? The other endstops are all functioning correctly, but "E" shows "yes" like its triggered all the time...