5 Cylinder radial somewhat based on the Morton but not much

[crueby]

Nice! great results!   

[gbritnell]

Hi Bent,
No they get further refinement. I think about 8 steps in all. After sawing them off a fixture was needed to do the surfaces on each side of the rocker. I already have an assortment of small clamps that I have made along the way. The fixture has a center post which locates the rocker then the two small clamps hold it in place. .015 is taken off the center boss and another .015 for the area around the boss which defines the circular shape and the bosses on each end.

[gbritnell]

That fixture was sacrificed by cutting a notch at the rear boss. This was to allow the 1/8 end mill access to step of the radius around the boss. The rocker was secured by a close fitting bolt with a nut on the back side. A .015 shim washer was made to space out the difference in depth from the ends to the center boss.

[crueby]

Very nice!  Could be made into mini telegraph keys too.  Watching along with interest...   

[gbritnell]

The final machining step was to put the .094 diameter pocket in the end of the rocker arm. This is where the push rod will locate. I couldn't use the first fixture plate so another had to be made. It was very similar to the first one but without the slot cut into it. The center of the end boss was established and the stop/locate boss was drilled so that the .094 diameter ball mill could pass through and cut the rocker.
The final 2 pictures show the rocker arms in various stages of finish. Once all the filing is done to the stepped off bosses the edges will all be radiused and everything polished with fine emery cloth.

[Kim]

I love seeing the process and various setups you use to get such a fine result, George.  Thanks for sharing your detailed process! 

Kim

[bent]

Wow, neat looking parts, there were a lot of steps left to do 

[gbritnell]

I finished up all (10) of the rocker arm pedestals. I cut a piece of aluminum stock to the required length and width but made it into one long piece. Enough to cut all ten plus a couple of extras. I then cut a slot the full length with a 3mm end mill. The slot is .125 wide but if I used an end mill of that size it would have cut oversize. The gauge blocks were clamped to the stock because it stuck out of the vise so far I knew it would vibrate and grab and ruin either the stock or the saw, or both.

[gbritnell]

With the pieces cut to length it took several more steps to complete them. First the rocker shaft holes were drilled and reamed. Next setup was to drill the mounting holes. Third step was to reduce the width and last to put the radius on the corners. The brackets, and rocker arms are complete no just have to finish the remaining rocker shafts. These are drill rod with a .02 wide by .015 deep groove cut in both ends for the E clips. The push rods are made in two pieces. The short side threaded 1-72 and the long side with the external threads. This will be for adjusting the valve clearance. I made a forming tool to put the radii on the ends.

[bent]

Ah, now I see the adjustment feature in the pushrods that Gerrit I think was mentioning.  Very cool...and also a bit jaw dropping threading 1-72 in what is basically thin wall tubing.  Very cool!