Made huge changes to Monoprice Maker Select to address Z-axis wobbling, before/after picture

Here is the before/after picture: http://ift.tt/2aUAh5C are prints of this model at 0.1 mm layer resolution. Note that I uniformly scaled the model to have a width of 45 mm. Also note that in the after print, I modified the front of the model so that the phone stands at a steeper angle.In the before print, I had the Z-braces mod installed. I was very impressed with the results at the time, but I felt the itch to make things even better.In the after print, the surface is extremely smooth and I can run my fingernails on it without them catching on anything. However, there are some striations in the print and I can feel that the surface is very slightly wavy. I’m working on figuring out why the striations exist.Here are the mods I made to achieve the results in the after print:1) Bought Misumi linear bearings to replace the stock Y-axis bearings.2) Bought this carriage plate. Drilled holes to support four linear bearings rather than three linear bearings. This puts two linear bearings on each Y-axis rod rather than having an unequal number of linear bearings on the two Y-axis rods.3) Flipped the belt mount on the Y-axis stepper motor (see here). This fixes the alignment of the Y-axis belt, which actually comes from the factory unaligned.4) Removed the spring belt tensioner from the Y-axis belt and tightened the belt by three teeth.5) Moved the filament spool mount from the top of the printer to somewhere else. Having the filament spool mounted at the top of the printer amplified vibrations generated by the printer. http://ift.tt/2aWsU0N

Question about using (and maybe extending?) a prusa mendel i3 for prosthetics.

I’m interested in learning about 3D printing, and hopefully one day participating in the e-nable projects or something similar. I recently found a decent deal (I hope) on a used prusa mendel i3. Whether I go with that one or buy a new kit, my question is the same; can I put a substantially longer leadscrew and set of rods on the bed to increase its build volume (for such things as forearms)? Would I have to slow it down, or print and install mounts for thicker rods? What’s the practical limit (is there a chance I could one day print all the parts for an arm in one shot)? http://ift.tt/2bjlMK0