Fix Thorlabs AD9.5F
The new Thorlabs adjustable aspheres (CFC-NX-A/B/C where N is the focal length) are a great improvement over the old models (CFC-N-A/B/C), but due to their shorter body length, installing them in the the SM1 adapter AD9.5F does not leave the FC threads exposed. Trying to attach a fiber like the one below will not work, because the female threads on the fiber cannot get inside the adapter to engage the male threads on the collimator. This is not a problem with all fibers, but it is a problem with many fibers that we have.
Using larger inner-diameter collimator adapters works, but then the collimator cannot be adjusted without removing it from the adapter.
One possible solution is to drill out the inner diameter of the AD9.5F so that the female threads can get inside the adapter.
I recommend using a 1/2" drill and drilling 0.15 deep from the side with the SM1 threads, as shown in this drawing. This allows the threads to be exposed sufficiently to attach our fibers.