Radius turning

[The Artilleryman]

Somewhere recently I saw detailed instructions/drawings/dimensions to build one of these

Am I just imagining it or was it on another forum ?

 

[123hotchef]

I could do with one of those also

 

[gaz1]

i prefer something thats fits in the tool holder

 

[Agroshield]

To find previous discussions from this forum, put the words below into Google (without the quotes). This will find the previous threads from here. There are links within those threads to plans for almost every style:

"ball turner site:mig-welding.co.uk"

 

[Fazerruss]

I built one several months.....

No welding on this project

For while now I've needed a radius turning attachment for the lathe and being a tight Yorkshire man I decided to make my own. And there's nothing off the shelf for a Colchester Bantam. Started with a lump of steel from the scrap bin. No idea what grade it is but it machines nice.

www.mig-welding.co.uk

 

[The Artilleryman]

To find previous discussions from this forum, put the words below into Google (without the quotes). This will find the previous threads from here. There are links within those threads to plans for almost every style:

"ball turner site:mig-welding.co.uk"

Many thanks for the above.
Nothing here so must be on another forum - unfortunately it's been down for several days so can't check it out.

 

[fizzy]

I built one several months.....

No welding on this project

For while now I've needed a radius turning attachment for the lathe and being a tight Yorkshire man I decided to make my own. And there's nothing off the shelf for a Colchester Bantam. Started with a lump of steel from the scrap bin. No idea what grade it is but it machines nice.

www.mig-welding.co.uk

And a work of art it is as well.
What sort of diameter balls/hemispheres will it turn?

 

[Agroshield]

The picture in the initial post is tiny so I did not realise until now to which particular design you were referring.

The one you show is a Chinese knock-off of the Repton RT1 ball turner. The current eBay sellers have reverse engineered the original Repton design. To the best of my knowledge, no plans for this specific design have ever been published. Repton no longer trade.

Instructions for it here: https://littlemachineshop.com/images/gallery/Instructions/4920ReptonRadiiTurner.pdf
More: https://www.model-engineer.co.uk/forums/postings.asp?th=94307
Noting its faults: https://www.madmodder.net/index.php?topic=10411.0

Hopefully the info. in the links above will allow you to decide if this design will do what you want and the pictures will enable you to make your own drawings.

The other very popular style with a vertical axis is the Steve Bedair one, for which there are plans (and see Mr Fazerruss' excellent take on it above).

The main alternative to the vertical axis style is a horizontal axis style using a boring head (see, for example, https://www.model-engineer.co.uk/forums/postings.asp?th=132138). All the overseas boring heads have a standard thread on them so you only need to make a back end for it and can reuse the head on the mill or in the tailstock for taper turning.

 

[Fazerruss]

And a work of art it is as well.
What sort of diameter balls/hemispheres will it turn?

I can do up to 70mm

 

[gaz1]

they are there but the forum software not searching properly

ive posted a few youtube vids for ball turning

Ball turning attachment recommendations?

I'm in the market for a ball turning attachment to fit my ML7, up to 60mm diameter and with the ability to turn concave etc. There is a limited number on eBay and they have mixed reviews, does anyone have any specific recommendations?

www.mig-welding.co.uk