Prusa i3 MK2 Extended Y Corners

WARNING - These parts require the Y-axis to be disassembled & reassembled. Only continue with this project if you're comfortable taking apart your printer, or if you're assembling a new printer.

Need some extra room under your Prusa for expansion? What a coincidence! These corners are extended by an extra 30mm (~1in), plus another 6mm if you decide to print the anti-slip feet.

I modeled these to make the MK2 compatible with Ystrouzas' excellent Prusa i3 Octoprint Raspberry Pi case. Without modification, the electronics box is barely too tall for the MK2 frame.

This model is a modified version of Prusa's Y-corners, found on Prusa's site. Included in the part is a captive M3 nut, so you can attach these feet to anything you like. If you're interested in damping your printer's vibration, you may want to bolt the corners to a concrete paver, as detailed by CNC Kitchen.

Print instructions

Here's how to put some big boy boots on your MK2 (also works on MK2S, MK2.5, MK2.5S with any MMU):

1. Download. You'll need the Extended Y Corner file. If you have flexible material, also download the Boot file.

2. Import the files into your slicer. You'll need 4x corners and 4x boots, printed in separate jobs. However, I STRONGLY recommend printing extras! You will not be able to print parts when your printer is in pieces. Both parts should appear in the correct orientation - the corner should have one vertical hole, with the support structure against the bed. The boot should have the bottom surface against the bed.

3. Slice. I printed everything at 0.200mm layers, although I believe Prusa uses 0.300mm layers in their print farm. Ensure that these parts are printed with at least 30% infill, and at least 3 perimeters - these need to be extremely sturdy. I printed the boots with 10% infill to ensure a little bit of springiness.

4. Print. I used the PETG Prusa uses on their print farm from FilamentPM's US warehouse. For the feet, I used ColorFabb NGEN Flex. Any flexible material should work.

5. Inspect parts. Make sure there's absolutely NO layer separation, underextrusion, or any other print defects that could negatively impact the strength of the corners. Remember, these parts are load-bearing, and need to be extremely strong to hold your printer together rigidly. If you see ANY issues with your print, go back to step 3 and change settings as necessary.

6. (OPTIONAL) Assemble. If you're using the flexible boots, now's the time to use 4x M3 nuts and 4x M3x20mm socket head machine screws to put them together.

7. Install. This is tricky. I recommend disconnecting all Y-axis cables from the board, then detaching Y from the frame by loosening the nuts holding the frame in place. Carefully remove the bed, then disassemble the Y-axis, keeping the old corners in storage just in case. Then, follow Prusa's Y-axis assembly manual. Substitute the Extended Y Corners in for all steps involving the Y Corners. If you have any difficulty, please don't hesitate to leave a comment, and I'll try to help as best I can.

That's about it! Have fun with your NBA-ready printer. Dang, that thing is tall!

-Brent