This is an exercise in turning as a favour for fellow AOMCC member Lee who is currently building a KH - a 500 cc twin. One of the delightful things that happen in the AOMCC is that members trade bits and information with each other - Lee gave me a new clutch adjuster for the W/NG recently, so it's my turn to return the favour and get some good turning and screw cutting practise at the same time.
His KH has a Vokes pancake air filter, which he wants to attach to a 276 carburetter. These are the dimensions:
We'll need a bit of this 2" brass bar:
I obviously didn't take too many pictures - I have finished both threads in this shot and have test fitted ot to a 276 of my own. I did actually turn a 1/2" length of the inner thread from a bit of thick wall tube to test it properly - this carburetter is in very poor shape so it's not a very good test.
Here's the finished adapter ring: