Prusa XL HyperPixel and RPi Mount

I saw the awesome design for the MK4 by @MekCreate and wanted to put it on my Prusa XL so that I could have OctoPrint with OctoDash.

https://www.printables.com/model/563030-mk4-hyperpixel-4
 

OctoPrint:

https://octoprint.org/

OctoDash - now with multi-tool/multi-extruder/MMU support!:

https://github.com/UnchartedBull/OctoDash
 

So I went about designing a mount that would fit his design for the screen and RPi. I also created a mount to take a DC buck converter to power the RPi from the 24V pins on the Buddy board.

The mount allows bolting up to the 3030 extrusion, even with the printer sitting directly on a flat surface.

Printing
 

• PETG
• 0.4 or 0.6 nozzle
• 6 perimeters
• 0.20mm layers
• 25% layer overlap
• 6 top and bottom layers
• 10% infill

BOM

In addition to what is required to mount the Buddy Screen, HyperPixel and RPi in the screen mount:

• 1 x RPi4
• 1 x Pimoroni HyperPixel 4 touch screen
• 1 x HW-688 buck converter  Yes, the link says it's an LM2596S, which it essentially it, but the addition of the USB outlet socket is what makes it an HW-688.
  
  https://www.aliexpress.com/item/4000004053109.html
   
• Double sided tape or a hot glue gun
• 2 x 3mm fork red crimp terminals
• 1 x 1m right angle USB A to C cable. I recommend this UGreen cable as they are very high quality and it was used for the clearances in the designs. You should be able to find them on Amazon in your own country.
  
  https://www.amazon.com.au/dp/B07ZGC7YFS?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_3&th=1
   
• 1 x 2m USB A to C cable. Again, I recommend UGreen.
  
  https://www.amazon.com.au/dp/B07PSHWSYB?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_3&th=1
   
• 1 x 1m 5.5x2.1mm lead
  
  https://www.aliexpress.com/item/1005004136058244.html
   
• 2 x M4x20 CSK bolts
  
  https://www.aliexpress.com/item/1005002400036568.html
   
• 2 x 3030 M3 T-nuts.   You should have some left over from the assembly of your XL. You will also recover 2 when you remove the Buddy screen mounts. If you want to get some more, use the link below.
• 2 x 3030 M4 T-nuts    I recommend the spring loaded ones, but use whatever style you like.
  
  https://www.aliexpress.com/item/33023772052.html
   
• 4 x M3x10 SHCS bolts. 2 of them can be up to 16mm thread length as I've made the holes in the mount deep to accommodate what people might already have on hand.
  
  https://www.aliexpress.com/item/1005002687219649.html
  
   

Assembly

Download and print the screen mount components from the link to @MekCreate's design above. Obviously, you don't need that parts for mounting it on the MK4. Follow their assembly instructions up to the end of Step 7, but using the arms from my models. I would not bother with the big heatsink they used, nor the fan; but I would use a standard set of RPi heatsinks.

https://www.aliexpress.com/item/33055043355.html

I highly recommend adding the light tube for the status LEDs from @Slacker_10917:

https://www.printables.com/model/744019-mk4-status-bar-for-hyperpixel-4-panel-v4

It' also a great opportunity to install my Improve Buddy Board Cover if you haven't already done so:

https://www.printables.com/model/859870-improved-prusa-xl-buddy-cover

Once that's done, you can move on to what is required on your XL.

Now straight up, you're going to hate me because this mod involves tipping your printer on its side and also removing the covers on the underside of the printer that retain the cable in the 3030 extrusion. :( Those things are a major PITA!


NOTE: Depending on how you handled your cable management during the original assembly of the printer, you will have put the excess cable from the Buddy screen at the Buddy board end or the screen end of the cable run. If it's at the screen end, you should be right, but if it's at the Buddy board end, then you need to manipulate as much cable as you can to the screen end. During my original assembly of the printer, I decided to route all of my cables down the right side extrusion.

I suggest test fitting the new screen mount with the screens to work out whether or not you are short on cable for the final assembly. Nothing worse than getting right to the end and finding out you're 2cm short on the the ribbon cable.

I recommend moving the printer onto a bench/table that gives you access to both the front and back or put it on a lazy Susan like this one from Ikea:

https://www.ikea.com/au/en/p/elritsa-lazy-susan-bamboo-40300290/
 

1. Using double sided tape or hot glue, mount the HW-688 buck converter into the mount and then put the lid on.
   
2. Grab the 1m 5.5x2.1mm DC power cable and cut off the female socket end. You want a cable length of ~750-800mm.
   Carefully strip the outer insulation to reveal the inner cores, then strip sufficient insulation off to be able to double over the conductor and and crimp on the fork connectors. The conductors are very fine, so you may need to add a touch of solder (I know, that's not good practice, but it's fine in this implementation) after crimping to retain them in the connectors. Alternately, you could extend the cables slightly with a slightly heavier wire to suit the crimps.
3. Remove the M3 T-nuts from the front extrusion that the Buddy screen mounts used and insert 2 x M4 T-nuts.
4. Measure centre and install the new 3030 Mount with the M4 CSK bolts. Don't tighten them fully yet as you will probably have to loosen or remove it when you do your final cable routing/management.
   
5. Remove the Buddy board cover.
6. Unplug the WiFi antenna connector from the Buddy board.
7. Remove the cable cover above the Buddy board.
8. When looking at the printer from the back, make a mark on the frame ~40-50mm above the the cable cover on the lower right side. This is where the bottom edge of the buck converter case is going to end up later. You can then remove the cover. You do not need to remove the left side cover if you worked out you have enough ribbon and earth/ground wire earlier on.
   
   
9. Lay the printer on its side (I recommend the right hand side) and remove any other cable covers on the route of the cables from the Buddy board to the Buddy screen. You do not need to remove the right side (when looking at the printer from the front) covers if you worked out you have enough ribbon and earth/ground wire earlier on.
10. Plug the USB cables into the RPi and the ribbon and earth bond into the Buddy screen.
11. This is the time to tighten the 3030 mount bolts and then install the screen mount into the 3030 mount. Start carefully routing the USB cables down the underside of the left side extrusion, reinstalling the cable covers as you go. This part is a little fiddly and may take a bit of to-and-froing to get right. Be patient and take great care not to crush or pinch cables. You are aiming to have the minimum amount required of the USB A end of the cable that powers the RPi to plug into the buck converter. 
    
12. Once all the covers are back on the bottom, put the printer back on its feet and re-install the corner cable cover and then insert the 2 x M3 T-nuts into the frame above the cover in the vertical 3030 extrusion. Be sure to route the other USB cable into the frame before inserting the T-nuts.
13. Mount the buck converter case using the M3x10 SHCS bolts. Align the bottom end of it with the mark you made earlier and plug the USB and 5.5x2.2mm cable into it.
      
14. Continue routing the cables up the frame and across to the Buddy board. Route the power cable to the terminal on the Buddy board and connect them.
    
15. Route the USB cable out the top of the back cable cover through the cut out that the tool head cables router out through.
16. Reconnect the WiFi antenna and reinstall the rear cable cover.
17. Reinstall the Buddy board cover.
18. Plug the USB cable into the USB C port on the Buddy board.
      
19. Inserter the 2 x M3 SHCS bolts into the side of the screen mount to securely retain it.
    
      
20. Drop in the mount cover to make it look pretty.
    
21. Finish installing any remaining cable covers and you're done! :)

As with all my designs, there are no affiliate links, etc. I get nothing out of them other than the satisfaction of helping the community and some Prusameters if you are kind enough to give my design a LIKE. :)

Happy printing and be sure to check out my other XL mods.

https://www.printables.com/@IPIND3D/models