Phone Bike Mount for M5 screws

The M5 makes the whole assembly a bit stiffer, don't overdo with the torque when mounting. Use the  shorter end of your Allen key for turning to limit torque. Perhaps use a bit of tyre tube as inlay in between the stem and the mount. With a bit of rubber even a low torque holds the mount very firmly, it is not possible to move it by hand.

All stls are included, also the FCStd. I only imported the original files and made the new cuts, so there is not a lot going on in the FreeCAD file. 

I printed the body and slider, which seem the most stressed parts, in Prusament PETG-CF (50% infill but infill modifiers with 100% in stressed regions), knob and bracket are printed in standard PETG (100% infill).  The bracket should give a bit of additional elasticity in PETG. Inserting a M5 washer spring first and then the M5 hex nut will give a little additional elasticity. Using an M5x20 bolt also leaves enough length for a counter nut. Use loctite on the nuts if you still are not sure. Use a second knob for countering slider and knob if you fear losing them riding without a mounted phone. 

Have fun,

emefff.