Refurbishing an Mk3S+
<introduction - optional read>
I'm a 3D printing enthusiast since I first heard about RepRap and had my first printer soon after. I don't remember when it all started, but "drive gear" was called "hobbed bolt" back then and you had to make it yourself to get your state of the art "Wade's extruder" up and running.
Later I had much less free time but a bit more money, so I invested in an Original Prusa i3 Mk2 kit. It was so "perfect" that I refrained from modifying anything. Disregarding a broken cable and some molten PTFE, this machine was a flawless workhorse. Had to give it away to make space for my MK3 which I upgraded until MK3S+ plus MMU2S. And it worked even better. Yes, you might call me a Prusa Fanboy, but I have my reasons. So much for the background.
The MK3S+ will be the desperately needed secondary printer besides an MK4S in a few weeks time.
</introduction>
I decided to
1.) NOT upgrade to Mk3.5/3.9/4 (because it's very expensive and a lot of perfectly fine working hardware would be thrown away)
2.) UPGRADE the MMU (worth the money)
3.) ignore "never change a running system" and rebuild/refurbish/clean the whole printer for the fun of it.
The printer currently works, only the Print Fan is starting to fail. But it was exposed to more dust and airborne cat hair than I'd like and thus I'm certainly changing:
a.) all linear and radial bearings,
b.) the cable sleeves (impossible to clean),
c.) all printed parts (new color scheme)
d.) nozzle & PTFE liner of the hotend,
e.) idler spring,
f.) print fan,
g.) hotend fan,
h.) trapezoid nuts.
QUESTIONS:
Do you agree with (a) through (h)?
What else could or should I replace that doesn't break the bank?
How about the Timing belts?
Any Upgrades I should consider that I probably don't even know exist?
The smooth rods look fine to the naked eye. Does that imply that they indeed are okay?
I believe all MK3S printed parts are from PETG. Would you go that route or choose a different material for all or some of the parts?
Any reason to replace the reverse-bowden PTFE tubes?
Any reliable mod to make the two fans less loud?
Sorry for being so elaborate and thanks for reading that far. Looking forward to your answers/comments.
Cheers!
RE: Refurbishing an Mk3S+
This is a very timely post as I'm in the middle of doing the same to two ex print-farm MK3S+ I recently picked up for a song. Both could have likely been fine with a couple new bearings and some replacement fans but I tore them down to their individual components and replaced pretty much everything you're considering. The outcome was great and I've been happily printing MMU3 parts to upgrade an MMU2s I picked up recently as well.
I would definitely replace the belts as its under $7 usd to replace both and its trivial to do when you're already planning to do the linear bearings. Same with the PTFE tubes (any and all) since they are so inexpensive.
Regarding the smooth rods, run your fingernail over them while rotating. If you feel any grooves just replace them.
RE: Refurbishing an Mk3S+
For the belts, it is worthwhile getting Genuine Gates 2GT belts
they have a characteristic red inner surface and perform better than cheaper belts.
https://ooznest.co.uk/product/2gt-gates-open-timing-belt-per-metre/
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: Refurbishing an Mk3S+
Thanks to you both. So I'm going to switch to genuine belts and check the rods with my fingernails.
Regarding the PTFE tubes: is there any profen benefit to the much more expensive ones like "Capricorn", "Triangle Labs",...?
@emiliobot : Congratulations on getting a second hand Prusa for a good price. Where I live, people tend to cling to their Prusas... like myself. 🤣 Hard to get a good deal.
RE: Refurbishing an Mk3S+
Yeah, I stumbled upon a deal and I'm glad to finally have some Prusa printers after over a decade in the hobby. The second-hand market has very much taken a hit due to some of the new entries into the space.
Regarding PTFE and Belts and such, I would reccomend just buying all your spares from Prusa direct. Its what I did and it made life much easier and I didn't have to worry about getting "good" parts.
I've used Capricorn in the past and honestly unless you've got retraction issues and are using long bowden setups I wouldn't bother.
Oh, and if your fans are noisy just replace them. My recently replaced fans are quiet enough I have to look at them to be sure they are running sometimes. Again, very reasonably priced direct from prusa (and with the correct connectors/sheathing).