I'd like to collect some feedback and/or spark some discussion around something weird that I may have noticed recently. But the backstory first:
I have a custom Toolchanger with a bed that has 3 individual Z motors that drive the bed via a simple kinematic mount. So before every print (in this order) I do the following:
- Home X/Y/Z
- Trim the bed via multiple G30 probes until the deviation is small enough
- Home Z again
- Create a new mesh via G29
- Run the print
Now this has always given me seemingly random issues, the trimming always works and the mesh creation also always seems to work fine, the resulting mesh looks believable etc.
However, sometimes the print just seems off, you can see the Z motors move fine, but the resulting compensation doesn't work out. Sometimes during the first layer of a single print the Z distance fits, sometimes it's too much, sometimes too little.
Prints with a large surface area to me are always hit and miss and I tend to avoid them for this reason.
However: Recently I seemed to have noticed that things work perfectly fine when the initial print goes wrong and I abort it, just to immediately restart the same print.
So basically, when I do my full calibration routine when a mesh is already active it actually seems to work...
This left me wondering and I am currently printing test samples of three different conditions:
- Unhomed, no mesh active
- Homed, no mesh active
- Homed, mesh already active
Now, did you ever encounter something else like this? Maybe purely creating the mesh doesn't always actually make use of it?
I've posted my actual config and pre-print routines many times before related to this issue and people didn't find any obvious issues in them, the main point of this thread is trying to collect some info around that new clue I might have found.