The Waveshare RP2040-Tiny boards and its clones are a pretty good option if you want to mod an instrument controller with the excellent Santroller firmware, they're fairly easy to work with and they have a separate USB-C daughterboard that connects with a ribbon cable. so it can easily be placed anywhere. This part replaces the battery cover with a mount that holds that USB-C daughterboard at a 35 degree angle where the batteries used to go.

I recommend printing in the default orientation with manual non-tree supports, placing supports in the areas highlighted in green. I also recommend using the following settings:

• Support type - Normal (manual)
• Support style - Snug
• First layer expansion - 0mm

You will have to be quite careful with the latch, the layer line orientation makes it very easy to break, this is very much not meant for constant removal. You could also try printing it with the USB-C port facing straight up, I have not tried so let me know in the comments if that works out well.

To assemble, thread the ribbon cable through one of the slots for the battery cover tabs like in photo #3 making sure it lies flat (the cover tab should sit above the cable), put the USB-C daughterboard in its slot and either glue it in place or melt the pegs with a soldering iron or similar.

STEP and Fusion 360 files are provided for editing, as you may have to tweak the tolerances to get it to fit properly.

If this model was useful to you, you can support me at ko-fi.com/lexd0g, it would be very well appreciated.