I need a mounting bracket that attaches a custom button box to the side rail of a Fanatec ClubSport QR2 wheel base mount. Most button box mounts out there are designed for profile rigs (8020 aluminum extrusion), but I'm running a Fanatec Cockpit V2 with the proprietary side rails, and there's nothing that fits cleanly

The mount should clamp onto the left-side rail (25mm × 25mm square tube with 6mm slot) without drilling, and hold a button box panel up to 150mm × 80mm. It needs to angle ~15° toward the driver so you're not reaching awkwardly mid-race. The clamp should be tool-free (thumb screw) so I can remove it for VR sessions where it gets in the way.

Key Requirements:

• Clamps to 25mm × 25mm square tube rail with 6mm T-slot
• Tool-free attachment/removal (M5 or M6 thumb screw)
• Supports panel up to 150mm × 80mm, ~200g max weight
• 15° inward tilt toward driver
• Clearance for cables running out the back of the button box
• Material: PETG or ASA preferred (cockpit sits near a window, PLA would warp in summer heat)

Dimensions:

• Clamp inner: 25mm × 25mm with 2mm wall thickness
• Arm length: ~60mm from rail center to panel mount surface
• Panel mounting holes: 4× M3 countersunk, 70mm × 140mm pattern (common for DIY button boxes)

Reference: Fanatec Cockpit V2 side rail profile is the same as their monitor mount rail. There are a few universal mounts on Thingiverse but they all wobble because they don't use the T-slot for anti-rotation.