I have an old Monoprice Select Mini Pro (v3) that has sat for years. I got it out today to see if it still works and it does. It printed fine the last time I used it but I've gotten bigger and better printers since then. However I lost the slicer profile I was using and decided to start from scratch with Orca. I just plugged in the dimensions and changed some start g code for the initial purge line as the default was going well off the bed. I also tried changing the retraction distance to 4.5 because this is a bowden tube which did not change this issue. The initial purge line and outer perimeter of the first layer stick really well but the middle infill is blobbing at one end and stringing through the middle and not sticking to the bed at all. I have been playing with the z height end stop (the level sensor is bad so I had printed an adjuster for the z end stop) to adjust the initial layer height and I'm pretty sure I went from too high to too low facing the same issue. I know it's not the filament because it's a new spool that I just printed on another printer with yesterday. I'm leaning towards it being a slicer setting of some kind having to do with the extrusion, I'm just not sure which setting it could be. Thanks for any help.
Edit: well the z axis motor just died because I lowered the z axis too far and it hit the bed and it was acting funny earlier so that's probably the issue.
Infill speed could be too high.
Can here to say the speed is too high indeed.
The extruder can not keep up at the high speeds. It has acceleration on. And in the beginning it's slow enough, but at the middle/end it's under extruding. It goes sigzag so that's why the patter looks like this.
Reduce speed, or get an higher flow nozzle/gantry/extruder