The 3D printer that I originally bought around 2014 was a Prusa i3 MK2. I chose the self build, as I wanted to know how the printer was constructed, and the instruction provided by Prusa are superb. The MK2 was upgraded to a MK2.5 and then a MK2.5S. However, it recently began throwing up all sorts of errors, including MINTEMPs and thermal runaways. I figured that it could be a number of sensor errors, but when inspecting it, and moving it to the workbench, I managed to break some of the plastic parts. This was probably due to the age of the machine (though could have be partially down to my clumsy handling).
As I have had it for about 10 years, and still need to do quite a bit of 3D printing at home, I decided to buy a new MK4S so that I could continue with my 3D printed projects (and also reprint the plastic parts for the MK2.5S). The MK4S is a huge upgrade from the MK2.5S and has some extremely nice facilities, including network capability.
With the MK4S up and running, I thought it would be nice to overhaul the MK2S and get it back to a serviceable condition (more print time). So, I stripped it down and cleaned the frame and hardware. I also printed new plastic parts for it using the MK4S. Here it is in its current state:
The plastic parts printed really well, but I’m not happy with the bearings (which are the old ones after I upgraded to a MK2.5). So I have ordered a new set this week and will replace all of them.
I’m about 1/2 way through the rebuild now, and it is coming along well, and everything appears to be fitting together as it should. The frame structure is now together, with new bearings for the Y-axis. There were some issues getting the frame square and level, and it required a lot of adjustment before it allowed the carriage to move smoothly:
The Z axis has also been installed with the bars for the X carriage, and now it just needs mounting on the base. Once this is completed, then the extruder and wiring can be installed:
My MKIIS was finished just before Christmas 2024, after re-printing all the plastic parts (on my MK4S) replacing the bearings and belts, bed sensor, PINDA, hot end sensor and print plate. When it was first (re)assembled, the self-diagnostic reported that the frame was spot on – it has never done that before (it was always just slightly out of alignment). It runs smoother than before, but still has a slight issue with stringing the filament, which I am working on. I even upgraded the filament support to a MK3/4 version – sp much easier to use, and includes a filament guide.
(The bass on the left is my vintage Kramer DMZ4001 which I have had from new, having bought it in 1982. It has been modified, replacing the pickups with schaller split neck pickup and adding a schaller bridge pickup. It weighs a ton.)