Actually beforehand I sliced them with prusaslicer 2.4.2 and had the files on my usb drive and just kept printing with them on there. I did update to 2.5.0 and did reslice them there with the new xy compensation value but the old files (gcodes) were from 2.4.2. But even before using the gcodes from 2.4.2 they were tighter back then. So I’m not sure if it’s an update issue
2.5 brought with it Arachne.
https://blog.prusa3d.com/prusaslicer-2-5-is-here-new-perimeter-generator-step-file-support-lightning-infill-and-more_70562/
The new arachne slicing is like classic combined with the thin wall setting and extrusion width optimization on remote control.
It makes changes to the extrusion widths, thinner or thicker as necessary, in an effort to make fewer passes and save time.
Example - Outer wall is 2mm thick. Vertical shell set to 2 perimeters.
Classic is going to do 2 inside and 2 outside perimeters at 0.45mm thick and try to crush another line in the center as gap fill. 5 passes.
Classic with thin walls detected is going to do the same but the gap fill will be done at 0.44mm and hopefully won't be pushing the walls out of shape.
Arachne is going to do the extreme outside perimeters at 0.45mm. The inner perimeters are going to be 0.55mm thick. The gap is already filled. 4 passes. On a large print this will save a lot of time.
The problem I see sometimes though, is the arachne slicing goes overboard and makes the walls and pieces measurably smaller. Which I believe you are experiencing.
Your nozzle also experiences wear over time, the diameter might not be precisely the same then 2 months ago, depending on how much and what materials you print. Get a hardened steel nozzle (or other high quality options) to mitigate issues like this
Did you use the same gcode? ...or did you reslice it using different software? Like a newer version of PrusaSlicer?
Actually beforehand I sliced them with prusaslicer 2.4.2 and had the files on my usb drive and just kept printing with them on there. I did update to 2.5.0 and did reslice them there with the new xy compensation value but the old files (gcodes) were from 2.4.2. But even before using the gcodes from 2.4.2 they were tighter back then. So I’m not sure if it’s an update issue
I would say switch it to "Classic" perimeter generator and see if that helps.
Have done that just wondering what is the classic perimeter generator and what does that do?
2.5 brought with it Arachne. https://blog.prusa3d.com/prusaslicer-2-5-is-here-new-perimeter-generator-step-file-support-lightning-infill-and-more_70562/
The new arachne slicing is like classic combined with the thin wall setting and extrusion width optimization on remote control. It makes changes to the extrusion widths, thinner or thicker as necessary, in an effort to make fewer passes and save time. Example - Outer wall is 2mm thick. Vertical shell set to 2 perimeters. Classic is going to do 2 inside and 2 outside perimeters at 0.45mm thick and try to crush another line in the center as gap fill. 5 passes. Classic with thin walls detected is going to do the same but the gap fill will be done at 0.44mm and hopefully won't be pushing the walls out of shape. Arachne is going to do the extreme outside perimeters at 0.45mm. The inner perimeters are going to be 0.55mm thick. The gap is already filled. 4 passes. On a large print this will save a lot of time. The problem I see sometimes though, is the arachne slicing goes overboard and makes the walls and pieces measurably smaller. Which I believe you are experiencing.
Your nozzle also experiences wear over time, the diameter might not be precisely the same then 2 months ago, depending on how much and what materials you print. Get a hardened steel nozzle (or other high quality options) to mitigate issues like this
Most thermoplastics absorb moisture from the air. This can change the properties of the material before and after printing.