Line boring on the lathe

[Alexander McGilton]

Here is an example of line boring on a mid to small lathe. 12inch swing. These are a set of 25ton hinges. 1.5inch radius channel milled then bored into these large blocks of steel on the lathe cross slide in the place of the compound. The boring bar is a large 2inch shaft with a reamed hole and set screw hole in the side at the middle. A broken end mill sharpened in to a tool bit is placed in the hole, adjusted by hammer and checked with a micrometer. The surface isn't spectacular from being w44 steel. Though it has worked as a unit for years.

 

[Batmanacw]

Here is an example of line boring on a mid to small lathe. 12inch swing. These are a set of 25ton hinges. 1.5inch radius channel milled then bored into these large blocks of steel on the lathe cross slide in the place of the compound. The boring bar is a large 2inch shaft with a reamed hole and set screw hole in the side at the middle. A broken end mill sharpened in to a tool bit is placed in the hole, adjusted by hammer and checked with a micrometer. The surface isn't spectacular from being w44 steel. Though it has worked as a unit for years.

Exactly the kind of stuff I'd like to do. I'm planning on a hole every 4" so I can work close to one end. My bar will be 32" or less.

 

[jwmay]

I'm considering setting up a few bars with equally spaced holes.

If it’s me, I’d be searching for a project that would justify storage of the newly made line boring equipment. But maybe your space limitations aren’t as rigid as mine. Otherwise, I’d not make tooling I know I don’t need, for an imaginary moment in the future where having it will save me time. But if your making them just to see if you can, then go for it.

 

[Batmanacw]

If it’s me, I’d be searching for a project that would justify storage of the newly made line boring equipment. But maybe your space limitations aren’t as rigid as mine. Otherwise, I’d not make tooling I know I don’t need, for an imaginary moment in the future where having it will save me time. But if your making them just to see if you can, then go for it.

I'm a bit confused. What storage requirements? It's a steel bar. It will stand in a corner or lay on a shelf. I've got dozens of bars of steel in racks. The 2" bar is in that rack now.

 

[DavidR8]

A while back I thought I was going to have to line bore an item I was making.
So I did a bunch of research on the subject.
Found Max Grant on YT and his videos were very helpful to me.
Part 1:

Part 2:

 

[Batmanacw]

A while back I thought I was going to have to line bore an item I was making.
So I did a bunch of research on the subject.
Found Max Grant on YT and his videos were very helpful to me.
Part 1:

Part 2:

I'm in the middle of this one now.

 

[jwmay]

I'm a bit confused. What storage requirements?

I assumed, having made a purpose built tool, it would go in a drawer. I don’t make things out of stock, to then store them on the stock rack. Don’t think too hard on it. My shop is small. If there’s not an immediate need for something here, it doesn’t exist. Nothing but material for making things is in the material for making things pile. And nothing made, is stored with the material for making things. Otherwise, it’ll get made into something else.

 

[Alexander McGilton]

Forgot about this photo, different archive.
Grind a better relief on the back of the cutter. Surface finish improves dramatically.

 

[Batmanacw]

I assumed, having made a purpose built tool, it would go in a drawer. I don’t make things out of stock, to then store them on the stock rack. Don’t think too hard on it. My shop is small. If there’s not an immediate need for something here, it doesn’t exist. Nothing but material for making things is in the material for making things pile. And nothing made, is stored with the material for making things. Otherwise, it’ll get made into something else.

Right now my 2" line boring bar is a raw chunk of steel. Most likely I'll make a holder for them hanging on the wall behind the lathe. I haven't decided yet. My main shop is 12x20.

 

[RaisedByWolves]

Right now my 2" line boring bar is a raw chunk of steel. Most likely I'll make a holder for them hanging on the wall behind the lathe. I haven't decided yet. My main shop is 12x20.

I can see what he’s saying, but if you have the space it’s your circus…

What I’m seeing is you’re going to need a big tooling plate to span that saddle properly.