Hope you are all having a very happy Christmas (or whatever else you celebrate). Stay safe !!

A special THANK YOU to everybody at the DUET team for your incredible service both in the design and especially the support !!

I just finished a test print with 100% success. Thanks for the suggestions.
I think the major problem was that I never removed the gap from when I was printing both the model and support with pla. I had completely forgotten about this.
I also printed slower although I don't actually know which of the many speeds is used - I suspect it was 26 mm/sec for petg and pla at 40 mm/sec.
The petg and pla stuck together to a limited degree ... enough to hold everything together yet not so much as to make support removal difficult.

I only have two words ...... Woooooo Hoooooo !

@alankilian, I REALLY appreciate any and all help and I apologize if you felt in any way slighted whatsoever. It was most certainly not my intent !!!
I got confused by the sentence "The point of continue is to skip an iteration."
DanS79 cleared it up and confirmed my interpretation by saying "To be clear it doesn't skip an iteration, it skips everything after the continue statement in the current iteration." IE it doesn't skip an iteration but goes back to the beginning of the loop.
Your example (thanks) did however clarify another point on the continue command that I was not aware of and hence my earlier confusion about sequential 'if' statements. The iteration happens over the 'while' loop and not as I had assumed over the 'if' loop. A very important bit of learning for me!
So to repeat, I apologize profusely and hope we are back on the same wavelength !

Moderators .... could we please lock this thread and stop with the negativity please ?

Another method that is often used with CNC mills is to allow the switch to be bypassed. Instead of the carriage directly activating the end switch, the switch is mounted to the side and a lever is used to activate it. The carriage approaches the lever and depresses it which activates the end stop switch but there is no hard stop so if it takes a mm for the carriage to stop, nothing is harmed.
You could use a micro switch with a lever with a roller on the end and have a protrusion on the carriage that activates the lever without running into a stop.
Hard to explain but very simple and effective.

If your offset values are zero, you are probing points that the Duet doesn't know about and you are then taking those probing points to adjust the mesh height. You are creating a bad height map and then applying it.
I don't understand how you can possibly expect any results but crap. You might as well work without any height map.
It's odd that you get stripes but before anyone can give you any suggestions about what is wrong, you MUST set things up properly !!!

This aught to be interesting: ) I got the popcorn, a glass of cool liquid and am ready for the entertainment

My biggest issue was using (and forgetting about it) gradual infill. For every gradual infill step, the infill percentage is halved and the vast majority of my lack of infill was because of that. I had very small infill steps at 1 mm so that most of the model was at very low percentage of infill.
I have also found that infill shape has a bit of influence over how things end up being sliced.
I am not sure that I found all the issues but I am good with what I have discovered.

To sum it up: Operator problem .... nothing to see here .... move along now ....

I have one printer running Duet2 plus a Duex5 - at this point, if it failed, it would be replaced with the same thing.
I have another printer that is running the original controller and it will get a Duet2 once I am finished building my third printer, a Jubillee. This one is a Duet3, primarily because of the CAN bus expansion and tool boards.
IMHO, a straight forward basic printer doesn't require the Duet3 and so far there aren't enough software add-on's to really take advantage of the SBC that you can run with the Duet3. If all you want is a nice controller to set up and print stuff, a Duet2 is likely your best bet. If, on the other hand, you like exploring and tinkering and playing at the bleeding edge then a Duet3 based system is probably in order

@Co3get, here is my heater section of config.g:

; Heaters

M308 S0 P"bedtemp" Y"thermistor" T100000 B4200 ; configure sensor 0 as thermistor on pin bedtemp
M308 S3 P"e2temp" Y"thermistor" A"bed sense 2" T100000 B4200 ; configure alternate or second bed heat sensor
M950 H0 C"bedheat" T0 ; create bed heater output on bedheat and map it to sensor 0
M140 H0 ; set bed heater to heater zero
M143 H0 S120 ; set temperature limit for heater 0 to 120C
M307 H0 B0 S1.00 ; disable bang-bang mode for the nozzle heater and set PWM limit
M308 S1 P"e0temp" Y"thermistor" T100000 B4200 ; configure sensor 1 as thermistor on pin e0temp
M950 H1 C"e0heat" T1 ; create nozzle heater output on e0heat and map it to sensor 1
M143 H1 S280 ; set temperature limit for heater 1 to 280C
M307 H1 B0 S0.6 ; disable bang-bang mode for the nozzle heater and set PWM limit
M308 S2 P"e1temp" Y"thermistor" T100000 B4200 ; configure sensor 2 as thermistor on pin e0temp
M950 H2 C"e1heat" T2 ; create nozzle heater output on e0heat and map it to sensor 2
M143 H2 S280 ; set temperature limit for heater 2 to 280C
M307 H2 B0 S0.6 ; disable bang-bang mode for the nozzle heater and set PWM limit

It's been a while since I set that up so am not too sure what all was done.
I do know that in order to display the second bed temperature on the graph in DWC, you need to go into the 'Extra' bit of the 'tools and extra' pane and flip the 'show in graph' thingy.

Hope that helps.

Yes, middle of bed for the sensor, offset a bit to not be directly where the bed wires go into the heat pad. I don't think it makes much difference exactly where it is located as long as it is somewhere in the middle-ish.

WoooHooooo ..... we have a winner !

I was at 30% cooling, tried 60% with only a tiny difference and then went to 90% when I got a perfect thread form!
The walls were always set to normal sequence (inside-out)
I did notice the slight curling as well but I would never have thought that my issue would be caused by insufficient cooling.
I was printing in PLA so I guess in retrospect it wasn't totally unexpected.

THANKS !!!!

Thanks guys, I will try printing inside out and increasing cooling air.

This is getting really weird .... when I print with a 0.1 mm layer height, around half the thread (as I go around the circumference once) prints ok (symmetrical) and the other half is flat(ish).
I am now resorting to more clearance in the matching nut because I have run out of ideas of what else I could try to print this properly.

Second print came out exactly as first print ... now trying a third print but this time with a 0.1 mm layer height .....

@diy-o-sphere, checked ... not enabled. Thanks for the comment!
I am printing the thing again on the hope that the printer had a case of temporary insanity.
I looked through the preview layer by layer and the thread is formed exactly as it should with symmetrical upper and lower thread faces. The matching nut 'seems' to have symmetrical threads although it's kinda hard to see. Of course the nut doesn't fit the thread because of tolerances and possibly because of the distorted thread. On the nut, each side of the thread has been offset by -0.3 mm for clearance but that isn't enough clearance yet.

I just printed a thread but it has got a serious lop-side issue. This part was designed in Fusion360 and the threads look perfect in the model. It was printed with Cura - and the threads look perfect when I look at the preview. The actual outcome is rather sad .....

The upper thread face is flat as a pancake.
Any thoughts on why this is printing like this ?

@gnydick, what temperature is reported by the current heater. There are two (or more) aspects to liquefying the filament. The most obvious of course is the hot end temperature. If you push too much material through it, you might see a drop in temperature shown on the temp graph. The other aspect is how fast the heat is conducted from the nozzle and hot end to the core of the filament. This is something that more wattage isn't going to help you with and is IMHO the bigger issue.
If you see a drop in the hot end temperature then a more powerful heater can help but if the temperature that you see is mostly constant then a replacement heater isn't going to do diddly squat.
I am assuming you have already increased the temperature of the hot end to let you extrude marginally more material but don't forget that this is really not the way to go as it is easy to overheat the outer material and still have the inner material too cold. In moderation, it can help.
Also, what happens to the filament when the flow rate drops due to the nature of the model? This can really throw all kinds of wrenches in the works. There is no such thing as a free lunch - if what you are printing requires a constant high flow rate then sure, optimize for that .... but be aware that you loose quality in low flow/high detail situations.
The Volcano is known to cause all kinds of drooling issues. You could also go with the Super Volcano but I can see the drooling issue being magnified by the Super Volcano (I tried the Volcano and have discontinued it's use, I never tried the Super Volcano)

To increase your extrusion rate, you can go with a number of different newer technology hot ends other than the volcano. These usually come with a bigger heater as well. There are a number of better hot ends out there that can flow more material and you can also go with the special nozzles that have a modified interior to allow more heat transfer to the filament. I don't recall the name of these at the moment.
Anyway, the Volcano is outdated technology and better solutions exist.

YMMV !!!

@deckingman, that would explain the wattage table but would lead me to wonder why nothing was said about that feature. Seems to me that this would be a game changer feature.
How lucky do you feel ? ...

I would like to add that it also really depends on what you are doing. If you are pushing a really large volume of filament through a really large nozzle than it might be ok. The picture shows a nozzle that goes with the kit but I didn't see the nozzle size.
Even if you are using a 1 mm or larger nozzle and intend on printing huge amounts of filament real quick, this should only be attempted by someone who REALLY knows what he/she is doing!
I personally wouldn't attempt to run this heater on 24V because of the danger involved .... but then I don't do base jumping or bungy jumping either .....

The table of output power vs temperature seems odd to me - while resistance does go up with temperature, they are claiming that the heater only puts out 46W at 280C and there is no mention of anything special for the heater that would account for this reduction in wattage when the heater is hot.
I suspect this is really a 50W heater with a really creative way of selling. Not unheard of in Chinese products.

Agreed with Phaedrux - being only 5C different is super accurate for the involved setup. Heck, even the thermistor by itself (assuming you use a thermistor) isn't normally that accurate. A lot of people use cheap IR meters for verifying bed temperature without being aware of all the various adjustments that have to be made to the temperature reading in order to get something even half way accurate.
To sum it up, don't fuss over actual temperature. If you find that 60 is too cold for your print, crank it up and don't get hung up on the actual reading or requested temperatures.
BTW, if you were to get an accurate reading of temperature all over your bed and not just at one point, you are likely to tear out your hair if you are concerned about 5C .....