Mesh Bed Compensation Screwy

GrodanB

Therefore my question:Can I cause this in the set-up file? (ie. is this possible to be my fault?)

Is the test plate you use leaning towards one corner?

Otherwise you have a hard time knowing if this is occurring.

Just preparing to test the latest mirror X and Y map:
-0.105, -0.135, -0.145, -0.112, -0.085, -0.130, -0.158, -0.155, -0.205, -0.247, -0.273
0.010, -0.043, -0.045, -0.057, -0.020, -0.045, -0.172, -0.108, -0.090, -0.175, -0.172
-0.040, -0.003, -0.037, 0.030, -0.003, 0.043, 0.003, -0.003, -0.110, -0.150, -0.168
-0.027, 0.037, -0.035, -0.020, 0.013, 0.000, -0.033, -0.070, -0.152, -0.178, -0.217
-0.035, -0.080, -0.043, -0.085, -0.080, -0.053, -0.135, -0.132, -0.160, -0.175, -0.245
-0.175, -0.240, -0.178, -0.130, -0.108, -0.088, -0.098, -0.120, -0.233, -0.263, -0.317
-0.263, -0.280, -0.200, -0.195, -0.247, -0.253, -0.288, -0.342, -0.290, -0.383, -0.385

Is there a way of getting the firmware to display the height map that is in use? both in numeric form and in graphical? so I can verify that the map I constructed in libreoffice CALC is the one in use?

This testing is sketchy at best… But than again this is the best result I have had in since I started with duet... (just mirroring the X have not started with the map above)

Tested mirroring both, and just Y... X seems like the one that is best to swap... Need to re-slice at lower speed and possible hotter bed...

CHP

@GrodanB

So the 90 degree is not in Y but in Z then…?
It's an axle which can rotate in X but also offsets the sensor 50mm to the right. It moves it nearer to the hotend since I have no hotend installed in the left slot of my carriage.

Is there a way of getting the firmware to display the height map that is in use?
For that I made this simualtion branch so I can test it on a PC. But you need Visual Studio 2015 (free express version) to run it:
https://github.com/ChristophPech/RepRapFirmware/tree/sim

I ran two of your examples through it at 2mm resolution. The easiest way to visualize is opening it in Excel and insert the 3D-Surface chart of the whole table with default settings.

https://drive.google.com/file/d/0B-DBgmDdShYnQWlFS2V3SDJpS0U/view?usp=sharing
https://drive.google.com/file/d/0B-DBgmDdShYnUnp0X1NFdVFWN1U/view?usp=sharing
(filename dates are references to the comment's times)

GrodanB

Thanks will check as soon as I get home.

Made a first layer yesterday and I raised one corner 1/8 of a turn and now the first layer is even with mirrored X axis compensation.

But using ABS and that suck big time when it comes to ABS not adhering to the bed… Most stick but one or more of the small squares will always fail...

CHP

I never tried ABS but for PLA and PETG I am using 90°C bed temperature otherwise it doesn't stick well without printing the first layer slower and squish it down.

I dislike squishing the first layer because it gives the print elephant feet also without serious slowdown stuff gets ripped off.

But at 90-100°C (surface temp on the bigbox is ~10° lower than the thermistor reports) the filament sticks well to the bed even at higher speeds and also if the nozzle is way to far from the bed. I could move the nozzle several mm above the bed, the first layer would still stick.

GrodanB

Do not like it either but this evil works with ABS. E3D edge there was no need.

Since I started using the mirror version I must say that the fist layer has never looked this good.