I have now installed a new sheet of plain black buildtak and sensor now works beautifully. Thanks for the help

Thanks Phaedrux,

I think I’ll go and get it changed all together then.

I’ll report back when I have tried that.

Brg

Hello,

I have had a Wanhao i3 for close to 4 years. It has alway been a pain to print big items as the realtively thin bed warps quite a lot.

A lot of progress has happened in terms of 3d printer control, so I concluded that I wanted to try to upgrade my controller to a duet wifi and add a probe for automatic bed leveling. The main motivation was the bed leveling and secondly a quieter printer - in the future I'll repurpose the duet for a homebuild printer.

I started by just wiring and configuring the printer with the duet wifi. I got that running and did a few test prints to confirm that config was on point. All well and good. The process was quite well described and documented

I then proceeded to install the DC42 IR probe. I printed this mount from Thingiverse (with my newly installed duet wifi):

https://www.thingiverse.com/thing:2191348

I guess its not ideal with the probe being Y -33 mm off from the nozzle, but should get me started.

From here my headache starts. I believe the probe works as i should. I have run through this setup multiple times:

https://duet3d.dozuki.com/Wiki/Using_mesh_bed_compensation

The problem is that the compensation is wastly exaggerated. Here's a picture of the mesh:

The bed is warped, i know that, but not that bad. When I hold a straight edge across the bed i different directions it seems more like a bowel shape. When I try to do a print it is obvious that the Z motors compensates, so no doubt it doing what its told. But some places it almost running the nozzle into the bed and the extruder skips - other places it raises the nozzle so much that its printing in air.

As said, I've run through the setup multiple times but also:

• Ensured that probing the same spot yiels consistent results
• Darkened the room
• Manually leveled the bed multiple times (I'm very familiar with the process - thats how I've done for 4 years)
• Done all above with nozzle and bed at print temperature

My print surface is a rather worn Wanhao version of what i believe is buildtak. Here's a picture of a incomplete first layer. As you can see, some places it's really close and other places too far away:

Relevant software info:

And config, homeall and homez:

config.g homeall.g homez.g

Please help, I'm lost for ideas