This is obviously inspired by Optimum Tech's Zeromouse and Zeromouse Blade, but using FDM and a more affordable donor mouse.

The thumb and finger rests are in a reasonable spot for me, and the buttons are lined up well.  The shell requires A LOT of bending and finagling of the button paddles to get the donor PCB installed.

The model is parametric, but it needs cleaning up.  I want to make it easy to adjust the offsets of the finger grabbies, but it is too messy for that so far.  I will post the OpenSCAD after I get it cleaned up.

My setup printed in PLA comes in at 16.43 grams with the VXE Mad R electronics.  

The button flapper paddles have less spring tension when printed with one perimeter instead of two, and the length of the plunger has been adjusted to make up for this.  I am using lightning infill, and I had to lower the “minimum sparse infill threshold” in Orcaslicer to 1 cubic mm to make sure the button arms would be hollow.  The width and thickness of the arms is dialed in for the springiness of PLA.

I do not have a Mad R Major to test, but it looks like it should fit just fine.

• v2.0 - Initial release of the Li'l Magnum for the VXE Mad R

• Li'l Magnum! shell for the VXE Dragonfly R1 / R1 SE / R1 SE+
• Li'l Magnum! shell for the VXE Dragonfly R1 Pro / Pro Max
• Li'l Magnum! Fingertip Mouse Shell for MCHOSE L7 Ultra

• Li'l Magnum! 22-Gram 3D-Printed Fingertip Mouse Mod For The VXE Dragonfly R1 and R1 SE at patshead.com
• Can We Compete With The Zeromouse For Under $25? at patshead.com
• Ultralight Fingertip Gaming Mice - Two Weeks With My 21-Gram L'il Magnum at butterwhat.com