I guess it could be that the bed is not level enough to start with.  I'll try setting it up more level.  Here's the result of Mesh Grid Compensation.

The bed was quite a lot out so I've levelled it and it's within about a mm I reckon.  Bed levelling should be able to cope with that.  My Titan bed is known to be 3mm higher at the back than the front but the Marlin bed levelling works fine on that.  I can't really imagine the Duet is more critical but it's still only probing 6 out of 9 points.  It only probes the second and third points in the Y axis.  Here's the results of bed levelling.

That doesnt look right to me. Do you have a bed.g file. If so what is in it?

Some useful info

https://duet3d.com/wiki/Setting_up_automatic_probing_of_the_print_bed

I think for corexy we should be using G29 not the blue button which runs G32 for deltas.

I think your probe points are too close to the edge (15mm) as your probe has an offset of 24mm.

I've read the link you posted above.  G29 is recommended and not G32.  Yes the blue button itself runs G32 and the bed.g.  The drop-down on it includes Mesh Grid Compensation.

I guess the probe points in the X direction might be a bit close - 175+24 = 199, but I would have thought it would have skipped the highest X values not the lowest.  Still, I'll try changing the mesh grid values.  Pity it doesn't allow for a different spacing for X and Y.

It does. Use Sxxx:yyy.

E.g S100:90 to get 100 x spacing and 90 y spacing.

Thanks - didn't find that.

Set values to

M557 X20:160 Y15:175 S70          ; Define mesh grid

and it's still the same.  The probing is well within the print area.

Try keeping all probes more than 24mm from the edge and see what happens. I'm not sure what the sign of the offset should be as my offsets are effectively x=0, y=0 with the piezo. Where is your probe in relation to the nozzle?

Gottit

M557 X25:165 Y15:175 S70          ; Define mesh grid

5 minutes ago, tekkydave said:

Try keeping all probes more than 24mm from the edge and see what happens. I'm not sure what the sign of the offset should be as my offsets are effectively x=0, y=0 with the piezo. Where is your probe in relation to the nozzle?

Probe is 24mm to the right of the nozzle ie. X+24 and no Y offset.

Ah, I've worked out the logic of the problem.  If the probe point is X=15 the X carriage must move to X=-9 which is impossible so the probe point must be more than the offset.  I was looking at it the wrong way.

Thanks very much for your help

I think thats the issue. 

I've adjusted the hardware bed levelling and got it more level.

That seem to be another hurdle overcome.  It's getting very near to trying printing now   Probably when even more fun starts

Tried printing having set up the CuraEngine slicer as seemed right, saved the gcode file, transferred it to the main computer and uploaded it to the Duet.  All the usual pre-printing actions happened.  Hotend and bed started heating up, all axes homed and it performed bed level calibration.  When hot it ran the extruder at an enormous speed and stripped the filament.  Not seeing a Stop Print I used Pause.  Then I searched in vain for a Stop Print control but no joy.  There only the Emergency Stop which turns everything off leaving filament in the hot hotend with no cooling fan running BAD.  Guess the work-around is to turn the heaters off and let the hotend cool before turning the main power off.

I shall have to take the hotend apart to unblock it - tomorrow, probably, as I think I've had enough for today.

When you've paused a print the buttons should change to resume or cancel. Cancel will stop the print.

Took hotend off, unscrewed heatsink and just pulled filament out from the bottom.  It had a blob on the end stopping it going either way.  Tried extruding but the motor was skipping a bit, may need more current.  Did extrude though even though it was ABS and the manual preset temperatures only go up to 135°C (I use 180°C for printing).  I think the preset temperatures may be changed but I can't see where ATM.

In settings -> list items

Thanks - thought I'd seen it somewhere   Done it - added 260°C   Trying the extrusion again.

Later...  Better but still skipping steps a bit.

Increased extruder current from 800mA to 1A and it's now extruding fine.  Might need more when extruding due to the pressure of squeezing the filament.

I had to push my Titan motor to 1200mA. The X/Y motors are at 1000mA and the Z currently at 1400 (1680 maximum).

Trying a test print again.  A more powerful bed heater would be nice as the bed takes twice as long as the hotend to reach working temperature.  I have a mains bed heater on order, on a slow boat from China, with nearly twice the power.