Lathe spindle bore fix

[Lil Foot]

While fabricating a new axle for my little dump trailer, I found a problem with the spindle bore on my Enco 9x20 lathe. It is supposed to have a .767 bore, but they left about 1 1/2" in the center of the headstock undersized & badly off center. Only about a .720 rod would pass through. It appears they (badly) roughed a hole from each end, neither concentric, then finished the outer portions from each end, leaving a mess in the middle. (1st pic)

The only boring bar I had long enough to reach in there was not stiff enough to cut the somewhat hard spindle.
Some digging through all my old tooling, I came up with a solution. My machine has OXA style quick change tool holders, which will only hold a 1/2" tool. I had an old KDK style holder that takes 5C collets, so I set out to make an adapter to put it on my machine's small tool post. Cut some clearance on the bottom, & drilled & tapped 3 holes. (pics 2,3,4)

 

[Lil Foot]

Then I took an old tool post t-nut & machined it as shown.

 

[Lil Foot]

Adapter installed on 5C KDK holder.

 

[Lil Foot]

Then I mounted a 6 1/4" long 3/4"dia 2fl solid carbide end cutting end mill in the holder, indicated it concentric with the spindle, and slowly plunge cut the eccentricity in the bore. This brought the hole much closer to center, & then I finished the bore by hand with a series of adjustable reamer cuts, finishing at .770 diameter through. My 3/4" axle now slides through with a little to spare.
And I now have a 5C holder for other stuff, even though it's a mite large for the machine.

Earned my pay for the week.

 

[Tooljunkie]

Nice. Had to build a tool to fix the tool. Good to rise to the challenge.

My little southbend 9x48 gets a new home this weekend,moving it across driveway to my small garage,16x24. Drywalled and spray textured last week,finished painting tonight. Lathe, brake lathe, hydraulic press, english wheel and bead roller all infrequently used and in heated storage (also has running water)

 

[Yooper]

That's awesome! That filler piece for inside of the QA took some set up time I'm sure.

 

[Lil Foot]

Thanks guys.
Yooper, coming from you, that's a real compliment.