I want to make this perfectly clear: the Molinari and Predator
extensions are identical.
A customer wanted to be able to use the Molinari extension from his
Predator cue. The problem is that the Molinari bumper - which MUST
be used with this extension - has metric threads. My lathe, which
would supposedly cut metric threads, could only approximate the proper
pitch. There was enough error that it just wouldn't work.
Yes, I could easily tap the hole & I did, in fact, purchase a tap set to
suit but tests showed that the tapped threads were torn & ragged like
you would expect. Most woods simply don't cut cleanly with a tap.
Yes, I'm spoiled. I prefer to live tool ALL threads. But since my
lathe couldn't handle the correct pitch, I decided to make an adapter on
my CNC machine. I programmed it to cut the internal metric threads
and then cut external SAE threads, which I CAN cut on my lathe. It
worked out very well.
You can see a video of the operation
HERE.
I finally got to the point that I could install the adapter & decided to
take a few pictures showing the process.
![](images/accessories/2N2B9322a_small.jpg)
Here's the butt of the cue with the 7/8-14 threads already machined in
it. Below are the Molinari bumper and the adapter shown in the
video.
![](images/accessories/2N2B9327a_small.jpg)
These pics show the adapter partially, then fully threaded into the
butt. The last pic is just for show :-)
![](images/accessories/2N2B9328a_small.jpg)
In this view, I've glued in the adapter, cut off the excess maple &
exposed the threads. It's now ready to use.
![](images/accessories/2N2B9330a_small.jpg)
And here's the finished product. I don't have an extension to show
you how it fits but it simply inserts into the hole in the bumper & a
half twist will lock it into place for the shot. Then, another
half twist will remove it.
=================================================
I have since revised my method. I no longer thread the outside of
the adapter - I simply turn a smooth diameter, then bore the buttsleeve
to accommodate that diameter. Since the adapter is 13/16" in
diameter and is installed 3/4" deep, this yields a glue surface of
almost 2 square inches, which is certainly sufficient to retain the
adapter. I will make another video showing this method the next
time I get a request to modify someone's cue.
I may even begin selling the adapters since the new method can be
practiced by anyone with a cue lathe.
Stay tuned!