Reinforced Prusa i3 MK2 Y axis motor mount with end stop mount

thingiverse

Update - I had moved the holes for the end stop back by 1mm in my original design because I needed to until I learned I could adjust it by the nuts on the 10mm rods. I had forgotten about that change when uploading the last version. V3 has the location of those back to the position of the original design. After dropping a spool on the original and breaking it, gluing it back together, and dropping the same spool twice more on it, I decided to make a new one. The original bothered me from the initial build because the belt tension caused the motor to skew on the two screw mount points. The design needed either a third support in the back like http://www.thingiverse.com/thing:406473 or http://www.thingiverse.com/thing:372192 or a stronger part with at least three screw connections. There are a few remakes out there for the i3, but I didn't find any for the MK2 with the endstop mount. So I made this one. It's a total remake with none of the original design. But other than being about twice as thick, it's an exact fit for all the screw holes, the placement of the end stop, the space for the belt and everything else. I based the new thickness on the x-axis mount at 17m. I've changed it a bit since uploading a few days ago. I've removed the dependency on rounded_box and made the cutout that was on the bottom more printable by giving it a gentle overhang that should print without support now. Instructions You will need one additional screw (M3 10mm I think), which is probably in your spares. I printed it in ABS with about 50% infill to be rock solid and it's been working perfectly on my i3 MK2. 20% or 30% would probably be ok with 1.5mm or better perimeter and 0.9mm face thickness. Thicker layer height makes for strong parts with better layer adhesion. I did 0.3mm layer height. You should not need to cut any zip ties, and will only need to loosen the minimum number of nuts to get the replacement done. Probably will take less than 30 minutes if you follow carefully (and I didn't forget anything) To install: Remove the endstop Place printer on it's side so the power supply is flat on a table. Remove the bottom screw from the Y motor and then the top screw to remove the motor Unscrew the 2 M10 (larger) nuts from the back Loosen the 4 M8 (smaller) nuts from the corner brackets but don't remove them Pull the two M8 rod assembly off the M10 rods, leaving the smooth rods with the rest of the printer On one side only, finger tighten the M8 screws again and then count the number of turns to unscrew them until they are loose Remove the outside nuts from the corner brackets Tighten the inside M8 nuts and washers against the corner bracket all the way, leaving the outside ones exactly where you put them. Tighten all the nuts all the way. Align the motor and end stop so that the wires are to the back and under the mount like they probably were before Screw in the bottom rear motor mounting screw (closest to the bottom M8 rod), not too tight Put the belt over the pulley and add the other two screws to the motor mount and tighten all the way, making sure the belt doesn't get too tight and break the other mounts. Secure the end stop on its mount with the wires routed properly Since it's not getting skewed anymore, the belt might be tighter, check for proper tensioning and adjust the nuts at the front of the system as needed so as not to change the end stop position. Put it back on it's feet and test If you are like me, you may want to make some better spool holders next Print Settings Printer Brand: RepRap Printer: Original Prusa i3 MK2 Rafts: No Supports: No Resolution: 0.3mm Infill: 50% How I Designed This The design is mostly based on using cylinders and hull to join them together to make the shapes and cutouts. This is quite easy to do since most of the cylinders used to make the holes will share the exact same center point as the ones used to make the outside shape, but with a bigger radius. The file could be parameterized to make it more readable, but since it's a one-off design, there should be any customization needed, so I didn't find it worth the trouble to clean it up that much.