When assembling the source print, the hooks holding the band broke, so I beefed up the design. While I was at it I:

Tightened up the clearance of the ends

Made one end longer and the other shorter. This gives more range and makes it easier to install the rubber band. Put the band on the long end , loop a string thru the band, pull it thru the tube and attach the short end.

I changed the clamp grips so they do not press the side buttons of the phone.

I adjusted the size for a wider phone.

Creality

Ender-3 S1

No

Yes

cubic.

press a 1/4 20 nut in the end recess