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.
@PriorityMotif You might have another (or an additional) thing to look at - there are little holes, which might be due to wet filament. This could also be the cause of the issue you are having - if the filament is too wet, it could cause partial blocking, which might create the thinning lines in the infill. This also would not be very visible in the perimeter.
If you hear pops during the print, then you have wet filament and, if that’s the case, I would suggest that you look into this first.
@Siff
yup, and I would also add that you can see the pressure is (consistantly) inconsistant, plastic is not flowing freely
@PriorityMotif