Upgrade your Mk2.5/Mk2.5S to use the new Mk3S+ extruder
I recently had to rebuild one of my Mk2.5S printers (blob of death) so I decided to print all the Prusa Mk3S+ extruder parts and see if I could get them to work on the Mk2.5
All I needed to do was design one bolt-on part to actuate the X-axis end-stop. Everything else is plug-and-play.
If your extruder is working, I do not recommend this upgrade - its too much work. But if you need to replace extruder parts anyway, I highly recommend this approach: maintenance on the new extruder is simpler, the filament path is better, and the filament sensor lever thingy seems to be more reliable.
This part adds an actuator for the X-axis end-stop which is missing from the Mk3-style extruders. The actuator also includes a fan cover similar to this one.
You will need a 25mm M3 bolt (bottom position) and one 16mm or 18mm bolt (upper position) to hold the part in place. Other than this, you'll need to do the Prusa Mk3S+ extruder conversion:
- Mk3S+ extruder parts
- 42.3mm PTFE liner (you can trim your old one if it is in good shape)
- Assembly instructions
Good work. I wanted to take a look at this upgrade too, however, as you said, to much work when everything works fine.
But will probably prefer updading another part, so I do not need to cover the fan. I understand you wanted to hide that "ugly" noctua fan, but mine is nice 😉
Anyhow thank you for confirmation, that the end stop actuator is the only not compatible part. There was some theoretical discussion about it, but have not seen a proof yet.
Btw I can still see a screw hole in the MK3S+ x-carriage part. So why just not to connect the endstop-block as it was for MK2.5S from the begining? You should have one from the disassembled extruder, so maybe you could be volunteer to test it 😉
You could augment the Mk3S+ x-carriage to provide the same end-stop actuation function as my part. Or re-use and modify the old Mk2.5S x-carriage part. As is, I don't think the Mk2.5S x-carriage parts are 100% compatible with the Mk3S+ extruder. There are some subtle changes in bolt locations from what I can tell.
In my case I wanted to use all 100% Prusa parts and just add another part instead of augmenting their parts and the purpose of the fan cover isn't to hide the Noctua, but to prevent my fingers from getting in there by accident 🙂
Well the Mk2.5S+ has been running flawlessly for 1 month and has printed about 6 rolls of PLA with no filament jams or X-axis crashes.
With this confidence, I just converted another of my Mk2.5 printers to Mk2.5S+ today mainly to correct some minor sagging of the extruder parts near the heater but also for the refined filament path of the S+-style extruder which should be more forgiving with respect to retraction settings for various filaments.
I also switched both to use this fan duct for more even part cooling: https://www.thingiverse.com/thing:4588226