It started as a normal classic UM, and was able get my hands on acrylic parts,
the fit of those parts were not as good as I wanted, and I had to adjust the parts here and there
Some time later I had a new project, that needed higher parts then the standard UM, and instead of gluing segments together, I though about enlarging my own UM,
The original UM hardware is very easy to adjust for a larger format, and only had to solder some extra length of wires for the endswitches.
I just used some old acrylic 8mm material and cnc'd all the parts, most was an easy fix, just add some 20cm between all the walls.
but I had to redo the z-stage, as the rods holding the platform were to wobbly at that height.
so I bought some cheap Chinese guided rails ans such, witch I regret a bit, because you get what you pay for
and so the UM++ was born
It now has a 20X20X40cm build platform, and works pretty good,
you do run into trouble when printing tall object with a small footprint, as at the top the nozzle drag starts to influence the smoothness of the print
and you really need some extra support, to stop it from moving about at the top
I also did some soundproofing, by adding rubber between the stepper motors, and (expensive) silent fans, this makes a very quiet printer, and and makes very little noise, and it's great to print at night, and wake up to a finished print.
later, because of small resonance, I glued all the panels together and added aluminum cross bars to the sides, this stopped most vibrations.
it is still an ongoing project, and maybe I will ad a heated bed, but I still print everything without any real problems.
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