Prusa Mk4/S swing out xLCD mount

One big gripe I have with the Mk4 is the LCD mount. Not only does it hang out over the edge of my desk, it can also get covered by the heatbed, making seeing or manipulating the screen mid-print difficult. This mod attempts to solve the problem. If installed correctly, the stock LCD cable is just long enough. And if you built your mk4 from kit, you should find most of the hardware needed among the spares left over from the assembly.

Important notes

1. This mod is only compatiable with the newer injection molded xLCD case
2. I do not have an prusa enclosure, so I don't know if this is compatiable
3. To swing the LCD fully in, there is a limit to the length of the USB stick. The one that comes with Mk4/S printer/kit has been verified to work. Though a shorter one is prefered

Print instructions

Open the .3mf files as project to see the recommended print settings and orientation. The swing arm needs to be very stiff, the best material is undoubtly PC-CF. ABS/ASA should also be fine. PLA, PETG, PA-CF are not recommended.

BOM

• 2x M3x25 socket head screws
• 2x M3x12 self-tapping screws
• 5x M3x12 self-tapping screws
• 1x M3x12 socket head screw
• 1x M3x8 socket head screw
• 1x M3x8 button head screw
• 2x M3 locknuts
• 2x M3 hex nuts
• 1x M3 M3nEs nut

Assembly instructions

1. Stock xLCD mount disassembly

• Follow the assembly guide in reverse to fully disassemble the xLCD mount

2. Printed parts preparation

• Join slot-insert and swing-arm-base with one M3x8 self-tapping screw
• Press two M3 hex nuts into the recesses on xLCD-back-cover
• Join xLCD-back-cover and LCD-case-mount with one M3x8 socket head screw and one M3x8 button head screw. You will need to use the ball end of your allen wrench
• Pre-tap the holes on xLCD-back-cover. Join connector-cover and xLCD-back-cover with two M3x12 self-tapping screws. Flip over, make sure the screws do not stick out. Unscrew the two screws
• Press two M3 locknuts into the recesses on the swing-arm-base and LCD-case-mount

3. Swing arm assembly 

• Assemble the swing arm with two M3x25 socket head screws. Note the orientation of the swing arm, it's not symmetrical. One end of the swing arm has a detent. This side mates with LCD-case-mount. No need to tension the bolts right now

4. xLCD case assembly

• Slide the xLCD into xLCD-back-cover. Make sure it's fully seated
• Put on xLCD-cover, flip over, screw the assembly together with four M3x8 self-tapping screws. Don't forget the PE Faston

5. Cable routing

• Reroute the xLCD cable and the PE cable as shown. Make sure there is as much free length as possible, without pulling hard on the cables
• Connect the xLCD cable, put on the connector-cover with two M3x12 self-tapping screws. Connect the PE Faston

6. Installation and adjustment

• Insert one M3 M3nEs nut into the right side of the front extrusion
• Screw the swing-arm-base onto the M3nEs nut with one M3x12 screw. Adjust the position of the swing-arm-base to make sure it's not pulling on the xLCD cable in its full range of motion. Insert the usb stick and make sure you can swing the LCD screen in and out without the it colliding with the right z motor
• Tighten the two M3x25 screw till you feel there's right amount of resistance in the swing arm mechanism

Known limitations

Even though I've printed the swing arm in PC-CF, currently there's still too much springiness to my likings. I don't think it can be eliminated by increasing the number of perimeters or infill density. But I'm already working on a (potential) fix. And I'll update when it's ready.