Need Advice For Using a Chucking Reamer

[Nogoingback]

I need to ream a 1/2" hole inside a 3/4" diameter piece of 12L14, 3 inches in length. I have a 1/2" chucking reamer to do the job. What diameter hole
should I drill/bore prior to using the reamer? And, should I ream under power a little at a time, or do it manually on the lathe without power?

 

[dpb]

I would drill it 31/64”, and run the reamer at 1/2 the rpm of the drill, fairly quick feed, no stopping or pecking. All the way in, all the way out, done.

 

[Norseman C.B.]

What he said with lots of oil......................

 

[Karl_T]

To be totally correct, a floating reamer holder is needed. Without it, the bore will be slightly bell mouthed. How much depends on the machine.

 

[Nogoingback]

I would drill it 31/64”, and run the reamer at 1/2 the rpm of the drill, fairly quick feed, no stopping or pecking. All the way in, all the way out, done.

The only problem is that my tailstock doesn't have 3" of travel: it's more like 2 1/4 - 2 1/2". My lathe is a 10" Logan. Could I ream as far as
possible on the first pass, reset the tailstock position towards the chuck, and start it up and finish?

 

[Nogoingback]

To be totally correct, a floating reamer holder is needed. Without it, the bore will be slightly bell mouthed. How much depends on the machine.

Not sure I understand why that would be. If I ream on the same lathe with the same setup, why wouldn't it just follow the hole? How much
bellmouth are we talkin'? A few thou?

 

[markba633csi]

I think the bell mouthing would normally be only a few tenths, from my experience anyhow. I disregard it on the rinky-dink stuff I do
m

 

[mikey]

The only problem is that my tailstock doesn't have 3" of travel: it's more like 2 1/4 - 2 1/2". My lathe is a 10" Logan

You could always bore it. If you need an accurate 1/2" hole you would either need an slightly undersized reamer to come in dead on size or you can bore it accurately. A 1/2" reamer will give you a plus-sized hole.

 

[Bob Korves]

You could always bore it. If you need an accurate 1/2" hole you would either need an slightly undersized reamer to come in dead on size or you can bore it accurately. A 1/2" reamer will give you a plus-sized hole.

Listen to Mikey. If you need to ream the hole instead of just drilling it, there is usually a reason for doing so. Are you attempting to achieve a press fit or a sliding fit, or what? To really be helpful, we will need to know exactly what you are trying to achieve with the reamer.

 

[Norseman C.B.]

The only problem is that my tailstock doesn't have 3" of travel: it's more like 2 1/4 - 2 1/2". My lathe is a 10" Logan. Could I ream as far as
possible on the first pass, reset the tailstock position towards the chuck, and start it up and finish?

Yes you can do it that way, I have when necessary, the finish wont be as clean but
reamed finish is not that great any way and what Mikey, and Bob said what
is the fit and finish your looking for............