- Joined
- Oct 3, 2013
- Messages
- 564
dennisgb said:Al-otment,
I do have a number of people who have the right equipment, but set-up could be complicated. The question is how much to spend. I do plan to put a mill in my shop but not anything big enough to handle the Norton. Maybe when I tear into it I will figure out that a little bigger machine could be of value...but those are slippery slopes...things seem to get bigger and better and start to break the bank.
Have you ever wondered how they fabricated the frames at Norton in the first place? You have to believe they had fixtures during welding that placed the parts in the right place...maybe they took them out of the fixtures and they changed shape...but if that was the case they should have been checked and fixed...maybe the specs were just to wide and they didn't know it.
As far as I'm aware, they used the common practice of bolting every component in a jig (all mounting holes pre-cut) and then welding the whole assembly. As olChris mentioned before, as the weld cools and shrinks every thing then distorts in relation to the amount of weld - and there's the problem. It makes sense that any welded frame should have critical mounting holes and axes cut after welding, in relation to the steering axis. I don't know all the reasons for the way the frames turned out, tolerances, quality control and cost are obvious factors, but judging by the amount of threads on forums regarding Commando handling, there's a lot of frames which require correcting.
When you start bending a frame to get one thing in line, you're going to set up stresses elsewhere in the frame which can put something else out of line. It's sometimes a necessary process where crash damage is evident, but wont be accurate enough. The assembly then needs checking on a surface table.