Drive shaft hole location?

I\'m working on the box cam and noticed that the holes for the drive shaft are not drawn in the same position on the plane (48-09).
The right side shows .625 down from the bottom of the side rail the left side in .481. Should I make the holes both .625 down and .481 in? I know they have to line up but what location is correct? I am aware that the left rail is shown incorrect in the plans and should be above the CL but I\'m not clear on the hole locations.  Thanks.

I made my holes .625 down and .481 from the back and they work great there.
bruski

Thanks Bruski. Also did you drill the 8 mounting holes before you cut the box cam? I seem to be struggling with the sequence of operations with the box cam and breech casing, maybe I making it more complicated than it is.
Bob

HI Bob,
 Turn your box cam to the sliding fit into the breech casing and turn the total length and then make sure to scribe a line for your bottom dead center and then insert it into your breech casing and drill the eight holes through the breech casing into the box cam. Then you can remove it and then cut the cam path. This way your holes will all be in the right place and at the same time your cam spacing will be set. You might want to make the recoil plate also so you can spot drill the 6 mounting holes in the rear cam piece. The 2-56 threaded holes are tiny, be carefull when tapping them. You might want to tap the holes before you spend a lot of time cutting the cam path.
bruski

Thanks Bruski.  That was sort of my plan I just wanted to make sure I was doing it right. I have the box cam made to specs and it fits real tight in the breech casing so I think I will do some drilling today. I was also thinking of making the recoil plate first for those 2-56 holes. I did practice one in steel and it went okay.  Thanks again

Bob

manatee, how did you drill the axle holes in the ends of the wooden beam so they are straight and square? I am thinking about using my 4 jaw chuck in the lathe but am worried about the chuck being able to hold the wood without it moving or worse yet, flying out.
bruski

I drilled them by hand using a drill guide I made from an extra piece of stock. I clamped them together in the end vise of my workbench. I didn\'t have enough Z clearance on my mill to do the job. I don\'t think it is that critical to the carriage. I was a woodworker long before I started working in metal.