Understanding internal boring....for machining bitches

[Beezil]

I dun git it.....

I need to do some internal boring on a lathe, and I'm not sure if i have the proper bits for it.

All I am doing is cutting a shoulder in some cold-rolled 1030 round stock, 2.75" in diameter for a timken bearing, I want kind of a press fit for the "cup" part of the bearing....

I've never done this before.....

can i just use my various bits that I use for external machining?

I opened up an MSC catalog to look at "boring bars" but I don't understand how they work.....

all of them have round shanks, but my tool holder is designed for bits with square shanks....

do I need an adapter?

what am i missing?

I'm not a machining bitch, dats fer sure!

 

[Flowers]

You need a Yankee Drill.

Flowers

 

[4ward]

A boring bar would be ideal in this situation, but you can get away with making your own bit with some HSS. It all depends on how deep you want to go.

Boring bars have round shanks with a flat milled into them to tighten the set screws against so that you can set how deep you want to go inside. The less you have sticking out of your toolholder the better (less chatter)

Oh yeah, you need a new toolholder if you want a boring bar that can take more than .010" off the ID and go deeper than 1". At least to do it right.

 

[Wayne Sihler]

Caution : I am NOT a machinest,However I have watched them at work as they made various parts for my XJ.
1 Drill out the hole to a size smaller than needed----Dooh
2 Measure to determine amount needed to fit bearing ,probably want 0.001 or 0.002 smaller for tight fit.
3 Boreing bar with cutter fits at right angle to the hole,use carriage to move cutter in and out and to enlarge the hole the necessary amount
4 measure often.
How deep inside the stock do you need to go?
Wayne

 

[Beezil]

we had some hss stock laying around....

made my own bit on the grinder.....took a while.

thanks, the piece is finished.....may post pics tonight....

btw, sean, it is the end-all-be-all wish bone joint.....uses opposed timken bearings and has adjustable bearing preload so you can keep a rattle-free tight fit......

hopefully it will be good enough to keep hinkley away from it in moab.....

 

[4ward]

I won't say it.

Forgot to ask, did you use your Shopsmith Mark V?