File Shaft

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Facing the boss

The housing has been mounted on a set of four 1-2-3 blocks as the drill bit and subsequently the reamer, needs to pass all the way through the bottom of the casting.  Here you can see the 3/8" hole has been drilled through the top and bottom parts of the casting.  This is the longest 6" long drill bit that I have.  I really want to drill and ream the top and bottom without having to move the casting to assure alignment.

Drilling file shaft bore

The plans call for a 7/8" hole and a bronze bushing to fit.  I think they did this so the builder can turn down a piece of 1" rod to fit the 7/8" hole.  I have a 1" chucking reamer bought and paid by another project, so I was inclined to go in this direction.  I was able to get some rough finish 932 bearing bronze rounds from McMaster that are 1.030 to 1.035 in diameter.  I can then turn this down to fit the 1" reamed hole.  At this point I drilled out the upper bore to 31/32" in 1/8" steps.  By extending the drill in the collet (had about 1/2" of drill shaft to grip) I was able to repeat the process in the lower bore without having to use a drill extension. 

Reaming upper file shaft bore

The big ol' reamer has been mounted and the upper bore has been reamed.

Reaming lower file shaft bore

I then raised the knee and reamed the lower bore.

Completed main housing

Now I have the upper and lower bores in alignment and bored accurately to 1".  I then set the Shooting Star up to do the bolt circle for the upper dust shield.  I elected to go with 6-32 instead of 4-40 hardware and adjusted the diameter of the bolt circle accordingly.

Unless I have missed something, aside from pressing the bearings in, I should be done with the body.


The completed file shaft. 

I was surprised that the O1 drill rod was as easy as it was to drill. 

I had some trepidation about drilling the 0.250" hole 3.125" deep, which is at the top end in this picture.  You can see the 0.125" vent hole about halfway down the length of the part.  Lots of lube, slow speed and pulled back to clean chips REAL often.

The bottom end in this view is drilled and then half cut away on the mill.


Bronze bearing ready to install.  I turned the OD of the bronze to match the bore with a 0.001 or so interference fit.  The ID was bored on the lathe to just under 0.500 with the intention of reaming in place for best alingment.

I caught myself before I started pressing the upper bearing in first...

Bottom bearing in place.  I used an automotive bushing driver and the big press. 

Top bearing in place and ready to mount on the mill and ream to fit.


The body was then set back on the mill and then the shaft was reamed to .0010 over with a chucking reamer.  This assured alignment and when you pull the shaft out it makes a satisfying "pop".


The "Hat' for the file shaft that doubles as a file clamp and debris shield.  Turned from a piece of 2" CRS


Tapping the 10-32 hole for the set screw using the BST Mini Tapper.


Hat clamp installed

The Hat clamp installed with a file.  I still need to make the dust seal for the top of the housing.