Here is a camera tilt wedge specifically designed and tested for the Martian II frame (Alien clone). Available in three (now four!) different levels of tilt 10, 20, 30, and 40 degrees. Bolts right on to the existing standoffs on the frame, no frame modification necessary!
The 30 and 40 degree tilts have an depressed area on the top so you can inlay materials like soft foam or moongel to help with vibration isolating the camera.
Secure the camera to the tilt using velcro strap found commonly at most home improvement stores.
Print with higher infill percentages for a stronger mount.