This is a follow on from my post about the horizontal arbor I aquired a few days ago.http://madmodder.net/index.php?topic=2058.0
Luckily for me, I have a few days to myself, so I thought I would get this out of the way first, before going back to my RT chuck holder.
So to get started, out came my notebook and a few measuring tools. This doesn't need to be a super accurate job except for the angle settings, they have to be spot on. Everything else will be made to split the line where marked. The casting isn't all that accurate on the outside, so things will have to be made to fit in places.
I am doing my little trick that I do with most things like this. The original equipment will not be touched, so I can revert back exactly to what it was before I started if needed.
The first thing to do was to accurately check the angles on the two mismatched parts. It turns out that the new bit is 50 degrees, and my machine is 55 degs. I quoted them as 55 & 60 in my other post, and that has now been corrected.
I searched all over my stock to find a piece of material to do the job and this is what I ended up with. It is not brass but some harder material, I suspect one of the bronze range. In fact it is a little short on height for the job, but that will not be critical in the long run.
The metal got a dose of side and face cutter, and was soon into the two bits I needed.
The two rough pieces look like that they will be plenty high enough, but once they have been dropped to the correct angle and had the locating faces machined, they will definitely be short.
So both pieces were fly cut all over, and they were brought into being perfectly square and parallel on all faces.
Now the parts were at a stage where they could be fairly accurately worked on, the retention faces were marked up and the first one was mounted in the vice.
My cheapo angle gauge was zeroed up on the table.
Then the block was set to the required 50 degrees. This is where squareness comes into it's own. If the sides were not parallel and square, the part could not accurately be mounted the way it is, it would be liable to be out of square to the vice fixed jaw.
I then machined downwards and sideways until I split my marked up lines.
Before it was removed from the chuck, it was checked to make sure it hadn't moved during the heavy machining. It was then stood upright, and the very sharp angled corner was flatted down slightly so that it would fit right into the corner on the casting machined angle.
A perfect fit.
The same crossways as well.
So what I will do for next time is get the other one to the same stage, then I should be able to cut the second angle.