I logged in to share my laser mount and then saw this thread. and I thought I had an idea of my own
I have a Chinese 3.5 W blue laser (not the J-tech one unfortunately) and designed a mount for it that had to be a quick snap one so I wanted to share it with the community. the mount is a snug fit design, but i forgot to count for the "inventables" label so I had to move it to the top side of the spindle mount.
I think this can be easily adjusted to fit the Jtech laser if any one can give me the mounting holes dimensions.