I am really hopeful for UBL to work properly one day. I spent about 5 hours trying to use it today, reading the user guide, and no luck. It sort-of, almost works... just enough to tease me into continuing to try. The manual is great at explaining steps that should work properly, but I think it also doesn't help you understand what's going on. The fact that it is also just wrong in some cases doesn't help.
Let me focus on the fine-tuning, since that's where I am right now. I did the cold probe, then smart-picked the other locations. I'm not at all sure why this is needed, since it was for points that were perfectly fine to probe. The addendum was wrong. The machine probed those points... why doesn't it keep the value it measured with my probe? No idea. But no bother, I figure I can simply adjust it. So I use the manual tuning with G29 P4 T. First, I go to one of the probe X/Y points, and then go to Z0 (all of this with the UBL activated, something it took me about 20 minutes to realize I had to do!) Now, I have the piece of paper, and see that it doesn't fit under the nozzle. The nozzle is resting on the bed. Great, so I need to adjust this mesh point up a bit... perhaps 0.1mm. G29 P4 T. The LCD shows 0.015. Unfortunately, the nozzle has been moved up, perhaps 0.75mm. Why didn't it stay in place so that I could use the paper feeler? Instead, I have to guess and check. I change it up to 0.115. During this, the nozzle is moving, even though the user guide says it won't (in bold). I save. I print the mesh to host to see that yes, it is now 0.115 at that point. I issue another G1 Z0, and the nozzle is still resting on the bed. Hmm. I repeat this, changing by 1mm.... this time, the nozzle is a tiny bit over the bed, but not enough for the paper to fit (normal paper, not super-fat 2mm paper, I promise!). I repeat and go about 5mm. This time, it goes up perhaps 1mm. Are these units actually mm, or something else? I'm very confused.
Should I edit the user guide and add my problems and these confusion points? Should I add something about how the Z-offset of my probe is completely ignored? (Changing it artificially by 2mm didn't change the cold-probe results by 2mm... I would think it should, but I don't understand what's supposed to happen... the documentation just isn't there.) What happens when I move the nozzle and UBL isn't activated? Does that mess something up? An explanation of how this works would be nice.
Massive apologies for this tirade. My next step is to dig into the code. I'm capable of a pull-request, so maybe I'll try that. But if I'm going that direction, I might just make some advanced values to manually offset the bilineal mesh values. No where near all of the excellent UBL features, but I think I could make it work.
Let me focus on the fine-tuning, since that's where I am right now. I did the cold probe, then smart-picked the other locations. I'm not at all sure why this is needed, since it was for points that were perfectly fine to probe. The addendum was wrong. The machine probed those points... why doesn't it keep the value it measured with my probe? No idea. But no bother, I figure I can simply adjust it. So I use the manual tuning with G29 P4 T. First, I go to one of the probe X/Y points, and then go to Z0 (all of this with the UBL activated, something it took me about 20 minutes to realize I had to do!) Now, I have the piece of paper, and see that it doesn't fit under the nozzle. The nozzle is resting on the bed. Great, so I need to adjust this mesh point up a bit... perhaps 0.1mm. G29 P4 T. The LCD shows 0.015. Unfortunately, the nozzle has been moved up, perhaps 0.75mm. Why didn't it stay in place so that I could use the paper feeler? Instead, I have to guess and check. I change it up to 0.115. During this, the nozzle is moving, even though the user guide says it won't (in bold). I save. I print the mesh to host to see that yes, it is now 0.115 at that point. I issue another G1 Z0, and the nozzle is still resting on the bed. Hmm. I repeat this, changing by 1mm.... this time, the nozzle is a tiny bit over the bed, but not enough for the paper to fit (normal paper, not super-fat 2mm paper, I promise!). I repeat and go about 5mm. This time, it goes up perhaps 1mm. Are these units actually mm, or something else? I'm very confused.
Should I edit the user guide and add my problems and these confusion points? Should I add something about how the Z-offset of my probe is completely ignored? (Changing it artificially by 2mm didn't change the cold-probe results by 2mm... I would think it should, but I don't understand what's supposed to happen... the documentation just isn't there.) What happens when I move the nozzle and UBL isn't activated? Does that mess something up? An explanation of how this works would be nice.
Massive apologies for this tirade. My next step is to dig into the code. I'm capable of a pull-request, so maybe I'll try that. But if I'm going that direction, I might just make some advanced values to manually offset the bilineal mesh values. No where near all of the excellent UBL features, but I think I could make it work.