[ATM] Threaded inserts for 1/2" carbon fiber tube?

["Chris Todd" <christopher.todd@gmail.com>]

I am having a tough time finding appropriate threaded inserts for 1/2"
OD pultruded carbon fiber tube I've obtained for use on a lightweight
6" f/5 dob I'm building.

When I bought the partially completed project components, the previous
owner had intended to use neoprene well nuts, but when I did a mock-up
assembly (before cutting the tubes to length and glueing the well nuts
in place), I found that the well nuts flexed quite a bit, primarily
due to the 1/8" flange that rests on the top of the tube.

I've Googled and searched McMaster-Carr for some kind of threaded
insert made either of hard plastic or metal, and I just haven't found
anything that seems quite right.  I'm concerned that self-tapping
threaded inserts will split the carbon fiber, so I thought if I could
just find threaded inserts with a smooth exterior of about the right
diameter, I could epoxy them in place.

For those of you who have used carbon fiber tubes, how did you go
about attaching them to your secondary cage and mirror box?  In this
scope, the secondary "cage" is a single aluminum ring 1" wide, and the
"mirror box" is a single sheet of 1/2" plywood to which the mirror
cell is attached (in other words, there really isn't a box).

Any thoughts, hints, or suggestions would be greatly appreciated,
Chris Todd
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