Using a boring head to set over for taper turning

[Richard StaceyParticipant @richardstacey70920]

I need to turn a taper which is longer than my top slide is capable of. Rather than set over the tailstock, I understand that it is possible to use a boring head to create the setover. What is used for the center? – all the boring bars seem to have parallel shanks but centers have tapered shanks- any help will be much appreciated.

Richard

[Richard StaceyParticipant @richardstacey70920]

[_Paul_Participant @_paul_]

Hi,

 

Why not make your own centre/s it’s what I do.

 

My boring bar takes 1/2″ straight shank tools so I get out my 3c 1/2″ collet mount some 1/2″ scrap bar (mostly from old printers) set the top slide at 30 degrees cut the 60 degree included angle then case harden the tip with Kasenit.

 

Sounds more complicated than it is.

 

Regards

 

Paul

 

 

 

[mickParticipant @mick65121]

Turn one out of silver steel, which will be a size fit to your boring head, then harden and temper to avoid wear. I’ve never used a boring head to this effect, it sounds fraught with dangers, what if the boring head slips in the tail stock spindle, which I imagine would take the whole assembly below the central axis of the machine, far better to set the tail stock over, you can’t go wrong that way, but good luck

Edited By mick on 23/10/2011 15:40:16

[Richard StaceyParticipant @richardstacey70920]

Many thanks Paul and Mick for your replies. I’ll give it a go and see how I get on.

Richard

[John Stevenson 1Participant @johnstevenson1]

Don’t bother with centres as they won’t line up anyway when doing a taper.

Use a bit of 1/2″ bar or whatever fits your boring head and pop a centre hole in the end.

Do the same for a piece in the chuck but don’t remove.

Then mount your work up using two ball bearings as intermediates. This way the angle is always taken into account and supported as well as possible.

 

Only way to do steep tapers.

 

 

John S.

Edited By John Stevenson on 23/10/2011 16:36:27

[Richard StaceyParticipant @richardstacey70920]

Many thanks John, your picture shows the set up very well – I’ll give it a try

Richard

[AndyBParticipant @andyb47186]

Hi,

 

Far be it for me to argue with John  but it really depends on the taper that you are cutting.

 

Morse and Jacobs tapers are fine; I have cut several of each using the boring head in the tailstock locked with a drawbar (you can do this on a Drummond but not on a Myford S7!!)

 

I use a straight shank rotating centre that I got from Chronos or RDG (I can’t remember which now) in the boring head and a plain in the mandrel, and centre deeply.

 

Works a treat every time.

 

Andy

Edited By Andy Belcher on 23/10/2011 19:28:48

Edited By Andy Belcher on 23/10/2011 19:31:47

[Richard StaceyParticipant @richardstacey70920]

Many thanks Andy, I have a Myford ML10 so using a drawbar is not an option but I will investigate a straight shank centre.

Richard

[David LittlewoodParticipant @davidlittlewood51847]

Richard,

 

If you want to turn tapers between centres, the ball bearing technique outlined by JS is probably best. However, if you find it fiddly and want to stick to using pointy centres, you would be better using a special curved centre drill to make the centres in your workpiece:

 

The holes so made are are more tolerant of slight offsets.

 

David

Edited By Diane Carney on 02/11/2011 15:01:26

[Donhe7Participant @donhe7]

Have any others had trouble with this thread exceeding the allocated

width of the page, with intrusion (or, rather, over-writing), of part of the posts

therein, by the adverts on the right-hand side of the panel??

donhe7

[John Stevenson 1Participant @johnstevenson1]

It’s caused by david littlewood stuffing a link up for a tiny centre drill that’s 23,986 times as big as the drill.

 

John S.

[David LittlewoodParticipant @davidlittlewood51847]

John,

 

Sorry about the length of the link, but it was the only one I could find in a reasonable amount of time. The sad part, of course, is that because of the daft way that the MSC website works, the link is broken… It’s the radius type centre drill on page 100 of the catalogue.

 

The word wrap works fine for me, so I don’t know why it causes problems for others.

 

David

[Les Jones 1Participant @lesjones1]

Hi David,

I think if you just put a short title (eg “This centre drill”) in the title box for the link instead of the ful URL then this may solve the problem. You may be able to edit your entry that is supected of causing the problem. I could see the problem using Firefox 7.01 but not with IE9.

Is this the link you wanted to insert ?

MSC page 100

Les.

[David LittlewoodParticipant @davidlittlewood51847]

Les,

 

Yes, it is. (Actually I had tried to insert a link to the detailed description you get if you click on the item, and it was this link which broke, and your one actually works).

 

I had just pasted the url into my reply, as I had not realised that there was that nifty method of inserting links. I thank you for pointing it out to me (and in a constructive and helpful manner); I have learned something useful.

 

David

[Les Jones 1Participant @lesjones1]

Hi David,

There is another problem that can occur when adding links. If you put in the URL starting with www the model engineers website URL seems to be appended to the start of the URL so it does not work. If you put in the full URL starting with http:// it seems to work correctly.

Les.

[John Stevenson 1Participant @johnstevenson1]

David,

You need to go back to your original post and either edit or delete the long links so the page can be read.

 

John S.

[David LittlewoodParticipant @davidlittlewood51847]

John,

 

Just tried to do this as requested (not causing any problems here, but happy to oblige). however, the usual edit button is not there; I have noticed before on this forum that it is sometimes visible on my own posts, sometimes not, with no obvious reason.

 

Anybody care to tell me what’s going on, and how to do it?

 

David

[David LittlewoodParticipant @davidlittlewood51847]

Oddly enough, an edit icon has now appeared on the above – but not on any of my previous posts!

[Author]

Posts