PRUSA MK3.5S MK4 Front panel for OSOYOO DSI 3.5" touch lcd screen

Custom Front Panel for Prusa MK3.5 with OctoPrint & Touchscreen Integration

I loved the idea of combining OctoPrint with a touchscreen user interface, but I couldn’t find any front panel design that accommodates both displays.

Since I’m upgrading my MK3S to an MK3.5, I decided to remix my previous front panel design to make it work with the new setup.

As with my earlier design, I wanted the Raspberry Pi to be mounted separately — typically placed above the Buddy board.
To achieve this, I chose to use the DSI interface, which allows me to connect a touchscreen via a DSI ribbon cable. This setup offers several advantages:

It decouples the screen from the Raspberry Pi.

It keeps the GPIO pins free.

DSI screens are typically plug-and-play, making setup easier.

For the display, I selected the OSOYOO 3.5” touchscreen with a DSI interface:
👉 OSOYOO 3.5” Touchscreen V3.0

However, I quickly realized that I couldn’t use a standard ribbon cable — the screen requires one from the same supplier.
Since my Raspberry Pi is positioned some distance away from the control panel, I had two options:

Buy a longer ribbon cable from the supplier, or

Use a DSI/CSI extender so I could use any standard cable.

I chose the second option and ordered this Adafruit extender:
👉 Adafruit CSI/DSI Cable Extender Board

Design & Assembly

Starting from the original XLCD R3 panel, I extended it to the left and created a slot for the touchscreen.
To make the setup more compact, I replaced the 11 mm hex spacers supplied with the screen with 5 mm brass hex spacers and 4 mm M2.5 screws.

The mounting supports are now integrated directly into the panel design — so there’s no need for larger printer feet to fit the panel.
Cable management follows the same route as the original LCD ribbons, keeping everything neat and tidy.

If you’d like a two-color print, the design files also include the MK3.5 lettering separately for easy dual-extrusion printing.

Bill of Materials

OSOYOO 3.5” Touchscreen (DSI interface)
Product link

CSI/DSI Extender Board – Adafruit #3671

M2.5 Hex Brass Spacers (5+4 mm, male-to-female)

Included with the Raspberry Pi heatsink shield I use:
Amazon link

Long DSI/CSI Cable (length as required)

4× M3 × 6 mm screws

4× M2.5 hex nuts

2× M2.5 × 6 mm screws for the DSI extender (optional)

2× M2.5 nuts for the DSI extender (optional)