I designed this to hold my helix in place and keep some of the cables more neat. I like the helix at a little bit of an angle to more easily reach the 2nd tow of buttons. I have seen others elsewhere, but wanted something different than what I have seen. On the back of each side is a channel to hook the cables into, so nothing gets bumped or pulled loose (see photos)

The right riser accomodates the additional bottom pads for the expression pedal, and the left is merely a mirror of the right. (Again, see photos)

The 2 sides join by using a piece of 1x4 pine (3.5" x 3/4"), which can be found at Menards, Home Depot, or Lowes, which costs less than $5. The board length should be between 16" and 17-½', attached with 2 #6 ¾" wood screws on each side (tighten by hand). The Helix sits firmly in place by the 2 pads under the back end. (Once again, see photos) When attaching the wood screws, I recommend flipping the helix and positioning the risers on the unit, to ensure exact alignment. 

There are also places on the bottom to add rubber pads, if needed. Or, to mount to a board, I recommend using longer screws through the wood cross brace.

This print does not require any supports and can be printed in PLA or PETG or whatever you have. I used PLA for the prototype and found it was very strong. I printed min with 15% cubic infill. I printed mine on a BambuLab P2S (256mm²), but I did design the parts to fit diagonally on a 220mm² bed.

I tried to ensure it is strong while minimizing filament. But my design skills still limited... 🫤

Hopefully, someone with a Helix will find this useful.