Round bar end radius tool?

[hotponyshoes]

I would like to put some round ends on some 10mm (varying between 9mm-10.5mm) round bar.

So end up with a dome on the end.(half sphere)
To make things more difficult the material is 316 but I could change it for 304 if required.

The lengths are fixed to something in one end so putting them in the lathe/mill is not an option.

I am sure I have seen a hand tool for this some time ago but it was either so cheap I didn't think it would be any good or so expensive I didn't buy it!

Only thing I can find now is like a reverse countersinkthat goes in a cordless drill (for deburring damaged bolt threads I think) and that looks like its going to cost me some fingers plus it's an bevel rather than a smooth radius.

I am thinking of something like a big electric pencil sharpener that I poke the rod into and pull it back out all rounded and beautiful.

Does anybody know if these things exist?

 

[jinjahbiscuit]

It could probably be done in a milling machine with a formed tool. Actually, it could probably be done in a lathe with the tool in the chuck and the material to be machined fixed to the top slide with some imagination and suitable clamping device.

 

[Greeves246]

This would be perfect but probably outside your budget.
https://eccentricengineering.com.au/index.php?option=com_content&view=article&id=37&Itemid=300

 

[jinjahbiscuit]

Nice bit of kit, but you could make a ball turner for less, plenty of information and videos on youtube. I understand though that the material hotponyshoes wants to shape would be difficult to mount in a rotating chuck?

 

[eLuSiVeMiTe]

https://www.arceurotrade.co.uk/Cata...s/Universal-Radius-Turning-Attachment-12x12mm
Dunno if you have a lathe?

 

[hotponyshoes]

I have got a lathe and a mill but the bars are fixed to something on one end so ideally I am looking for something I can use on the free end by hand.
There might be an idea by @jinjahbiscuit
If I could find and mount a suitable cutter in the lathe chuck I could make a clamp to put the end of the bar in the cross slide.
Or, on the same lines, if I could find a suitable cutter I could mount it in a router and fix a guide block to the base...

 

[RichardM]

What about the type of the ball ends Dr AL has used on his bandsaw rebuild?

 

[jinjahbiscuit]

A picture or two might be worth posting, so as to give us a better idea how the part could be clamped. Many "milling" tasks can be carried out using a lathe (I've cut keyways in shafts for instance) with a bit of thought.
Alternatively, some careful grinding, file work and polishing can produce good results with patience. Assuming you don't have 500 to make that is!