Thanks Greg. Yes I've developed some of my own ideas and techniques with fibreglass / carbon fibre - which is half the fun of ATM'ing! The thing I love about fibreglass is that you can make complex parts that would cost a lot of money to make out of metal.
I made a little more progress this weekend:
- Made the stainless threaded inserts for the 45Degree fibregalss hub (used to attach it to the aluminium collar with M4 screws) and glued them in.
- Completed the interference fit of the aluminium collar to the titanium tube.
FYI - an interference fit is made when one part has a smaller diameter opening than the part that it fits over. In my case, the ID of the aluminium collar was 0.075mm smaller than the OD of the titanium tube. I heated the collar to 250C in our oven (expanding it by approx 0.18mm) and put the tube in the freezer for a while. I then clamped the tube upright in a vice and (quickly) took the collar from the oven and placed it on the end of the tube (see image below). After a quick wiggle the collar fell and fully engaged the tube (I had a lip on the collar so it didn't slide all the way down!). Once it cooled the collar tightened very firmly around the tube.