Boring on an angle

Hi,

I want to bore into a bar, along it's length but coming in at an angle. So I need the drill - reamer mounted into the spindle, the bar mounted into the cross slide or tool post, so that the bar is running along the length of the lathe but on an angle so that the bore comes in from the side and drills intowards the centre of the bar.

The bar diameter will only be about 15 - 16 mm and the bore(s) (there will be three of them at 120 degrees).

What's the best way to achieve this please, I will try to draw what I am after if I can and then upload the picture(s).

Many thanks,

Ian

Would it be possible to drill and ream from the centre of the bar ?

Roy

Ian,

Your proposed general set-up sounds reasonable; but a couple of suggestions, if I may:

1. Consider mounting an indexing device of some sort, to the distal end of the bar, and clamping the bar in a split sleeve.
2. Mill three flats on the proximal end of the bar, to give the drill an easy start.

MichaelG.

Hi,

Roy, if you mean from mid point along the length of the bar yes, if you mean from the centre of the bar outwards that's not going to give the desired result.

I will try to take a photograph at some point, that should show you what I am trying to achieve. It will also show how precarious my current method is.

Michael, You are very close to describing the method I use at the moment, I actually use a 10mm end mill and clamp the bar in the tool post, the problem is that this method is reall a lash up in respect of clamping the work piece. Amazingly I got away with it the first time on a test piece but to be honest my tool post is too small to provide deep enough clamping of the work piece and I think I might actually be about to develop a workpiece launcher at any time!

Am I right in thinking I should make a split sleeve or is there something commercially available?

Once again thak you both, for taking the time to reply and help.

Ian

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Ian,

Split sleeves are available for clamping boring bars ... but, if you are limited by the tool clamp dimensions, you may need to think 'out of the box' [take that as a hint].

MichaelG.

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https://www.smithy.com/accessories/NDctNTIw

Edited By Michael Gilligan on 30/04/2017 22:15:58

Sounds like a job for a Hex ER collet block packed up and clamped to the cross slide or mounted on a vertical slide. That will take care of your indexing and clamping needs in one.

Split sleeve as Michael suggests or a Vee block again on the cross/vertical slide would also work

Edited By JasonB on 01/05/2017 07:30:28

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Haha thank you gents, something like the square or hex collet holder would be perfect, seems so obvious now you have pointed it out doh.

Many thanks again,

Ian

Gents,

Thank you for the helpful input, thought it would be nice to give an update.

I have ended up using 5c as I found a better choice of fixtures in this mode and can work with a slightly greater diameter workpiece.

Once again thanks for you help.