What spare parts do you keep printed out and ready for your Prusa?
Bottom line: For those with an i3 MK3S+, what parts do you keep printed out as spares for your printer?
Why I'm asking: I have a Prusa i3 MK3S+ and recently had an issue where my extruder body party got messed up. Fortunately (since my Ender 3 Pro has been unreliable from the start), the damaged part is still able to hold the hot body in place so I can print a replacement. I've downloaded the STL and am printing out a replacement now and later I'll take apart the extruder/print head section and put the new part in place before printing out anything else.
I've never worked with something like a 3D printer, where you can make your own replacement parts, before. There's also the issue that, since I'm in the US, if I had to order replacement parts, my printer would be down for a good while. Eventually, when I finish calibrations for the new logic board on the Ender, I'll be able to use that if I have to print replacement parts. Of course, I could just print one of everything and keep 'em in a cabinet, but that's a significant investment in print time and it uses filament (although filament cost is not extreme, it's a factor).
That leaves me wondering what people have found are the parts most likely to need replacing or what parts they pre-print and store in case of breakage.
Best Answer by Neophyl:
Fan shroud. That’s about it.
The pinda probe mount can sag if you print higher temp materials a lot in an enclosure so a spare of that part would make sense but I f you are going to do that anyway then you might as well print it out of a higher temp material than petg so when the time comes and you need to replace it then it won’t happen again.
RE: What spare parts do you keep printed out and ready for your Prusa?
Fan shroud. That’s about it.
The pinda probe mount can sag if you print higher temp materials a lot in an enclosure so a spare of that part would make sense but I f you are going to do that anyway then you might as well print it out of a higher temp material than petg so when the time comes and you need to replace it then it won’t happen again.
RE: What spare parts do you keep printed out and ready for your Prusa?
What he says. A couple of fan shrouds. I also had to replace the PINDA holders a couple of times but that's all. Of course I have the privilege of multiple printers. If I had only one I may keep a complete hotend parts set on hand but it feels like overkill.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
RE: What spare parts do you keep printed out and ready for your Prusa?
Interesting about the parts both of you mention. I had taken the whole extruder/print head unit partially apart and looked at the damaged parts from the inside and printed the back of it, then realized it was the front that was melted. The back includes the SuperPinda holder, so I guess I now have a spare one. The parts that were bad are the fan shroud, so I've printed 2 of those (one for now, one to keep) and the part above that. I forgot what it's called, but it's basically the front half of the upper part of the extruder/print head unit.
One odd thing: With any files I've downloaded from Printables or Thingiverse or other sites, I've had no problem printing them straight and everything fitting. I know that's just luck. But it's also ironic I print out the Prusa parts and have to take a Dremel to them to make sure they fit so the screw will go into the nut where they join.
RE:
Before I printed my spare off I modified the pinda holder design to add in more support structures so it’s not just connected at one point. Was easy enough to do in Blender.
The thing about the PRUSA prints, those machines probably have thousands and thousands of hours on them, I’m not surprised that your prints turn out better.
RE: What spare parts do you keep printed out and ready for your Prusa?
One of the first things I did once I had my MK3 tuned in, was printing all STLs for the printer - keeping them all in a box. For things that are close to the hotend like fan attachments I have more than one copy as I've tried with different materials - at one point they "kinda" melted, so I now keep a few of those on hand "just in case". On the original MK3 that I have only a very thin piece of plastic with a screw holds the blower on to the channel - it will crack if you over-tigthen the screw or if you screw up and "bump" into things on the plate. So keeping spares results in a simple/fast way to recover.
I have copies of all STLs because my non-Prusa printers all had issues with cracks and bad prints.
RE: What spare parts do you keep printed out and ready for your Prusa?
Before I printed my spare off I modified the pinda holder design to add in more support structures so it’s not just connected at one point.
The problem I had this time was that part of the previous filament I used (orange) was in the PTFE tube going into the hot end. It wasn't a cut section, like a few millimeters of filament. It was a crescent shape. The black filament I was using when it jammed was in there, too. Due to humidity (yeah, that's come up in a few threads where I've asked questions and I'm looking at storage solutions and driers now), I had another issue where a piece of filament broke off in the extruder. I got some of it out with a needle nose pliers, but some broke off so I had to take off more from the assembly to get to it. Both those experiences have started me thinking about the possibility of redesigning those parts so it would be easy to get to the PTFE tube or to pull more filament out of the extruder again. As it is, I've found that I can get the front of the extruder/hot end (is there a better name for that whole assembly?) and back in in somewhere around 30 minutes, but if I could just pop off something to get to the inner parts, then pop it back on again, that'd be nice. Is there a thread or a place for discussions on mods to Prusa printer parts?
Was easy enough to do in Blender.
I'm using Blender. Everyone tells me to use Fusion360, but there are multiple reasons I like using Blender and I've found it's not as hard to do precision work in it as some have said. One reason I'm sticking with it is because learning new mouse and keyboard commands for each program drives me nuts. Even switching between Blender and PrusaSlicer is enough to confuse me because of the different mouse movements they both use.
The thing about the PRUSA prints, those machines probably have thousands and thousands of hours on them, I’m not surprised that your prints turn out better.
Good point.
For things that are close to the hotend like fan attachments I have more than one copy as I've tried with different materials
As I'm looking things over now, yes, I think it's going to be parts near the hot end that I'll be sure to keep on hand.
I have copies of all STLs because my non-Prusa printers all had issues with cracks and bad prints.
The only other printer I have is an Ender 3 Pro, which has been madness to get working. (Turns out Creality was selling incompatible attachments for their own printers. They knew they were incompatible, yet said nothing and kept selling them. Took me FIVE months to finally find out that the touch probe of theirs that I added on would not work with their firmware and wouldn't work with most firmware out there!) All the parts for that are metal, but, of course, the community has created many additional accessories for it.
RE: What spare parts do you keep printed out and ready for your Prusa?
@tango You need to have the printer "dialed in" first before attempting to re-print the components for the printer. This can take a while, particular if you're new to 3D printing. And you need to know which filament to use, the type and ensure it's not "rotten", not consistent etc. - use the Prusament early on will help you get some consistency at a cost. But it's worth it to avoid a lot of headaches. As to mods, there are a lot of forums - most sites like printables are full of people's modified printer setups. But before you venture out into that, keep a full version of all the original pieces handy - trust me, you'll need some of them if you start "hacking" too much, and being able to reset and go back is very important.
I love Blender - but not for engineered 3D printing. Most of the stuff I do requires features to be in precise locations and dimensions and Blender is more of an artist tool so when you want precision you have to go through hoops. Freecad or OpenSCAD are my preferred 3D modelling tools - OpenSCAD by far the one I'm most comfortable with. FreeCAD is, well, to me not very reliable - it crashes too often, and I find myself fighting it too much. That said, a lot of our tools include the Slic3r can change preferences on how the mouse/keyboard should work so you can get things to look better. In FreeCAD you can choose "Blender" as your setting for keyboard/mouse 😀 You're right, getting used to 3-4 different way to navigate a model is hard.
When I started with a no-brand i3 printer, things broke, guides were wrong and it was generally hard getting anything complex printed without a ton of issues. Prusa printers put all that behind me. I can still put it together, hack it but I know it's been well tested and documented. Which is why I keep using the printers.
RE: What spare parts do you keep printed out and ready for your Prusa?
My prusa was an original MK3. With the old filament sensor that uses similar technology to a mouse rather that the newer and in my opinion worse break beam setup. The only problem with the old one was it didn't like some filaments like transparent and dust could clog it up. Of course the community redesigned things.
I ended up going with a Bunny & Bear redesigned extruder that makes it a geared extruder and also has a small bearing in that the filament sensor detects instead of the filament directly. https://www.thingiverse.com/thing:3560341
It has several advantages like its possible to get the front off and full access to the hotend without removing the back 🙂 When I did the rebuild I also fitted connectors to all the front parts, so my thermistor and heater cartridge can all be changed out simply without undoing the wiring loom. The Pinda mounting point was the same though so I ended up adding the extra supports for it. It also uses the Mk3S fan mounting so new fan shroud designs for the S can be used. As the fan is also on a connector I can test out new ones easily too. I guess I have a completely custom extruder now lol. I am happy with how it works though.
There are other redesigned extruder system you could look at too that have many quality of life improvements.
Do stick with Blender is you can get on with it. Once you learn some workflows and keyboard shortcuts then yes you can do really precision work. The fact you can select any part of the geometry of a model and move it a precise amount using the keyboard only is very useful and fast and learning a non destructive workflow really helps. I mainly do practical type prints but I did do one sculpting based model and the fact its all there in one package is extremely useful. I'm not the quickest and most of the functions around lighting/rigging etc I know nothing about as all I'm really using it for is modelling. Make sure you enable the 3dPrint tool for sure. The model analysis in that is really handy and the one click stl export is a time saver too.
On the filament unloading problem, one 'trick' that I use is to always load first. Like if my printer has been off and is cold, with the previous filament left in it I'll preheat the extruder to temp and instead of selecting Unload filament, first do a Load filament. Then immediately after the load has finished do the unload. Zero ptfe tube issues since I started doing that.
RE: What spare parts do you keep printed out and ready for your Prusa?
There are other redesigned extruder system you could look at too that have many quality of life improvements.
Greg Saunier is working on V2.0 of the Bear extruder, which is geared and uses the Revo Micro hot end. If wanting to upgrade to an improved extruder, I would maybe hold out for that one.