Turning hemispherical ends on rods

With one of these.

It's originally sold by Arc Euro for the C1 lathe but with an extra mounting it fits any of the larger lathes as well. This is mounted on a 6" centre height CVA lathe.

.

-- Regards,

John Stevenson Nottingham, England.

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Depends on material, diameter and accuracy required. If you want to d

the job well then Hemingway Kits sell the Radford design:

-- Myford Mat

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John,

Am I interpreting that picture correctly when I say the cutting tool is mounted 'upside down' and the handle is facing the rear of the lathe?

Does that tool work better than the adapted boring head you posted a while back?

Ed

John Stevens> >

Correct in the interpretation of the layout Ed

It works no better or worse than the boring head setup but this one is easier to use and mount.

On a small lathe like the Myford you could be struggling to get the boring head idea mounted into a tool holder due to bulk.

Regards,

John Stevenson Nottingham, England.

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Go to gadgetbuilder.com/ballfixture.html Worth a look.

Try this URL for that link:

I am currently building a variation of the above (when I catch up with post-holiday workload) designed by a chap called Holescreek on the PM forum, and re-designed by me to fit an ML7.

It's a very nice design with a dovetailed slide, gib strip, and micrometer-type adjustment, and pivots on a taper roller bearing.

Probably a lot more work than needed for the task it's intended for but it is a nice exercise in machining with a lot of different setups required, and for me at least half the fun is actually in making it.

Peter

In article , John Stevenson writes

The alternative (which does not require you to make/buy a gadget) is to use co-ordinate turning (small, calculated movements of leadscrew and cross-slide) to give a slightly rough hemisphere, and then smooth with a dead fine file. Works well, costs nothing to try.

David

And that brings me to the "The Machinists bedside reader". Don't know which issue, but simply buy all 3. They are worth it. The method is described in one of them. Not too complicated that it requires a book, but ...

Nick

And now to another method: Get an old file, anneal it, file / drill / mill /turn the wanted radius (and the relief) harden, temper and stone it. With low RPM and lots a cutting fluid you get a radius.

Or you can buy an *expensive* carbide radius bit.

Nick

I suspect that may be beyond my present abilities to make!

Brenda

-- anotheri

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There are many ways to do this.

The Hemingway one is virtually the same as using a boring head without the saving of having to make the tool and also the boring head can be used as a boring head and also for taper turning but that's another story..

I do have a radiusing attachment that fits the CVA, a really nice piece of kit, micrometer dials etc., but it takes that long to fit and setup that unless your delight is in the doing and setting it's a waste of time, I prefer the end result.

I believe Marv Koltz does a program that works the infeed's and offsets out for you, an updated version of the Machinist Bedside Reader.

Plunge cutting with radiused cutters doesn't work on small lathes due to the chatter.

If you only need to make one size you can use an old file or a bar of ground flat stock and make a lever thru form tool that do just that one size with very good results.

-- Regards,

John Stevenson Nottingham, England.

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When are you going to get Ketan selling Stevenson Quick change toolposts?

Mark Rand RTFM

Can't make them cheaply enough. To be honest I only made that design as at the time there were no imports.

I recently bought one of the 200 series toolpost's off Ketan for an outside job and the quality, fit and finish were awesome. It was ground all over, even on parts that were only cosmetic.

I don't regret making it but I wouldn't go down that path today.

-- Regards,

John Stevenson Nottingham, England.

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Gee, John, at least spell my name correctly (Klotz, not Koltz) so they can search for it.

The program is called BALLCUT and the price will appeal to all - it's free.

Regards, Marv

Home Shop Freeware - Tools for People Who Build Things

I'm glad I don't pay for my time:-)

Mind you, the £270 that Macready's wanted today for my stocking up on EN8 hurt a bit (one length each of 1/2", 3/4", 1" and 1 1/4" round and square)

Mark Rand RTFM

'S alright. We know who you are, even if John's been eating the aluminium swarf again.

Mark Rand RTFM

Sorry Marv, Dyslexic keyboard

-- Regards,

John Stevenson Nottingham, England.

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That looks like what I want, thanks! I'll give Arc Euro a call.

And thanks to others for all the info, more than one way to skin a ca I now see.

Brenda

-- anotheri

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