Ball Turning attachment for a Cowells?

[SherlockParticipant @sherlock]

[SherlockParticipant @sherlock]

First Let me say Hello. I'm not only new here, but new to Lathe work also and my knowledge is very limited. I am recently the proud owner of a Cowells ME90

I wondered if anyone new of a Ball/radius turning accessory that will fit this lathe without too much or any trouble? Being new to this game I am still unsure what aftermarket accessories I can and can't use off the shelf.

Thanks

[Michael GilliganParticipant @michaelgilligan61133]

Greetings, Steve

I haven't made one yet [it's on the infamous 'Round Tuit' list] ; but this looks a very adaptable design, and could easily be scaled-up a little : **LINK**

https://www.tapatalk.com/groups/modelsteam/ball-turning-attachment-for-my-watchmakers-lathe-t13409.html

MichaelG.

Edited By Michael Gilligan on 01/08/2018 19:59:05

[SherlockParticipant @sherlock]

Thanks Michael,

That does indeed look great, but as simple as that would probably be to make for you guys, I think I would struggle right with that right now given I'm an absolute novice, particularly since all the milling duties would also have to be confined to the lathe, but maybe something I could build down the line as my skills improve.

I noticed Ebay has plenty for sale, but not really sure if any on there would be suitable or fit I actually don't need it to turn a full sphere, it would be to chamfer and half dome some round for a volume knob.

[Michael GilliganParticipant @michaelgilligan61133]

I take your point, Steve … but I do think it's worth noting that design : You may well stumble across something that could be adapted to take the place of the trickier components.

MichaelG.

[Clive Brown 1Participant @clivebrown1]

Posted by Steve Sherlock on 01/08/2018 20:21:18:..

I noticed Ebay has plenty for sale, but not really sure if any on there would be suitable or fit I actually don't need it to turn a full sphere, it would be to chamfer and half dome some round for a volume knob.

 

 

If it's just a "one-off", consider making a graving tool or graver by sharpening a piece of tool-steel, silver or HSS, and mounting firmly in a good sized file-handle. This can be used with an improvised hand-turning rest in the tool-post to shape your work-piece. Rather like wood turning. Metal removal rate can be quite quick and a good finish is fully possible on steel or non-ferrous.

Clive

Edited By Clive Brown 1 on 01/08/2018 20:39:42

[SherlockParticipant @sherlock]

Posted by Michael Gilligan on 01/08/2018 20:32:30:

I take your point, Steve … but I do think it's worth noting that design : You may well stumble across something that could be adapted to take the place of the trickier components.

MichaelG.

Aha! Never thought of that Michael! Good thinking! Thank you

[SherlockParticipant @sherlock]

Posted by Clive Brown 1 on 01/08/2018 20:32:52:

If it's just a "one-off", consider making a graving tool by sharpening a piece of tool-steel, silver or HSS, and mounting firmly in a good sized file-handle. This can be used with an improvised hand-turning rest in the tool-post to shape your work-piece. Rather like wood turning. A good finish is fully possible.

I never knew that was possible but that sounds great and will definitely give that a try. I am learning lots already Thank you. Forgive my ignorance but the cutter have to be ground to any particular profile? Just currently studying and trying to get my head round the whole tool grinding area.

[DalboyParticipant @dalboy]

If it's just a "one-off", consider making a graving tool or graver by sharpening a piece of tool-steel, silver or HSS, and mounting firmly in a good sized file-handle. This can be used with an improvised hand-turning rest in the tool-post to shape your work-piece. Rather like wood turning. Metal removal rate can be quite quick and a good finish is fully possible on steel or non-ferrous.

Clive

Edited By Clive Brown 1 on 01/08/2018 20:39:42

If you Google "woodturning ball jig" and look at images there are a selection of ball making jigs used on woodturning lathes maybe be able to adapt to work on a metal working lathe

[Anonymous]

I'd just add three chamfers with a knife tool and do the rest with an ordinary file and judge the shape by eye. Once the basic shape is obtained finer files and wet 'n' dry will achieve the degree of finish required. If a more accurate shape is required make a template out of card or sheet metal.

Andrew

[Mick B1Participant @mickb1]

Use a file or wet&dry as Andrew suggests – or I've found it successful to mount radius router bits in a toolpost to use as form tools; cheap carbide bit sets like this:-

**LINK**

I've used them on brass, bronze, steel and titanium.

[SherlockParticipant @sherlock]

All Great suggestions guys and a massive help Thank you. I would have never have thought of the router bits and being a wood worker I have plenty of them to hand

[Mick B1Participant @mickb1]

I've mounted router bits on top of packing pieces and tightened the clamp screws straight onto the round shanks. Fiddly to set up, but simple and firm enough once you get them on centre height. Go slow, use a bit of oil and adjust them back and forth so you're not trying to cut along the whole rad at the same time until the final finish cuts. The acorns in my album pics were done that way.

[IanHParticipant @ianh]

I use a small/miniature commercial boring head bought at an exhibition mounted horizontally in a tool holder.

Another approach that might appeal if you are making a number of balls to the same diameter is to bore a piece of silver steel bar to a diameter 0.7 times the diameter of the ball you are aiming for. Then turn a chamfer on the outside to give a sharp edge. Harden and temper.

Rough turn the ball, then use the tool you have just made by hand to finish the ball. There must be something on the web that shows this if you have a root around…

Ian

Edited By IanH on 01/08/2018 21:52:30

[Reg WortleyParticipant @regwortley]

You might consider a Turnado from Eccentric Engineering, see advert to the right of this page

[Michael GilliganParticipant @michaelgilligan61133]

Posted by NZreg on 01/08/2018 22:45:17:

You might consider a Turnado from Eccentric Engineering, see advert to the right of this page

Maybe a little on the large side for a Cowells ME90 90ME

MichaelG.

.

http://www.cowells.com/90me.htm

Edited By Michael Gilligan on 01/08/2018 22:56:09

Edited By Michael Gilligan on 01/08/2018 22:58:59

[SherlockParticipant @sherlock]

Posted by IanH on 01/08/2018 21:51:31:

I use a small/miniature commercial boring head bought at an exhibition mounted horizontally in a tool holder.

Another approach that might appeal if you are making a number of balls to the same diameter is to bore a piece of silver steel bar to a diameter 0.7 times the diameter of the ball you are aiming for. Then turn a chamfer on the outside to give a sharp edge. Harden and temper.

Rough turn the ball, then use the tool you have just made by hand to finish the ball. There must be something on the web that shows this if you have a root around…

Ian

Edited By IanH on 01/08/2018 21:52:30

 

 

Thanks Ian Both interesting ideas just been watching videos of the boring bar attachment to see how that would function. will see if I can find one of the other method you mention

Posted by NZreg on 01/08/2018 22:45:17:

You might consider a Turnado from Eccentric Engineering, see advert to the right of this page

You know what, I saw that thing earlier this week whilst trying to find a solution and thought it looked marvellous I had no idea you could freehand a tool on a metal lathe, like wood turning and that really appeals to me for certain applications, However, I think Michael is probably right. I went and took a look at my Cowells after checking out Turnado videos and forgot how little room to manovere I've actually got 😀

[Michael GilliganParticipant @michaelgilligan61133]

Here's a minimalist design, marketed for the Unimat SL

**LINK**

https://www.ebay.com/itm/201082367536

I'm pretty sure you could make something equivalent, Steve

MichaelG.

[Cornish JackParticipant @cornishjack]

Which Cowells 90 do you have, Steve? – the 14 x 1.5 or the 14 x 1?

I ask because, (if you don't already know), the 14 x 1 can use Unimat 3 accessories. If it's the other one, you can get individual or multiple mandrel thread blanks as standard wheel studs. it's also possible to purchase replacement mandrels to convert to 14 x 1, from Cowells.

rgds

Bill

[SherlockParticipant @sherlock]

Posted by Michael Gilligan on 01/08/2018 23:17:54:

Here's a minimalist design, marketed for the Unimat SL

**LINK**

https://www.ebay.com/itm/201082367536

I'm pretty sure you could make something equivalent, Steve

MichaelG.

 

That looks just the ticket Michael! Perfect. and likely within my limited skills to fabricate also!

Posted by Cornish Jack on 01/08/2018 23:23:27:

Which Cowells 90 do you have, Steve? – the 14 x 1.5 or the 14 x 1?

I ask because, (if you don't already know), the 14 x 1 can use Unimat 3 accessories. If it's the other one, you can get individual or multiple mandrel thread blanks as standard wheel studs. it's also possible to purchase replacement mandrels to convert to 14 x 1, from Cowells.

rgds

Bill

Thats Fantastic news Bill. I believe mine will be the 14 x 1 as it appears to be a later model with emergency cut out buttons. Valuable information to know. What sort of accessories does that open up to me besides chucks?

[VicParticipant @vic]

I made this type for my lathe, pretty simple construction.

**LINK**

There also used to be a small commercial radius turner called the “Repton” but I haven’t seen it advertised for a while.

Edit. Looks like you can still get it in the US.

**LINK**

[thaiguzziParticipant @thaiguzzi]

If you have a boring head for your mill, make a MT-parallel sleeve adaptor and housing for your top slide or tool post, a handle, and voila – ball turning tool.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by thaiguzzi on 02/08/2018 15:04:59:

If you have a boring head for your mill, make a MT-parallel sleeve adaptor and housing for your top slide or tool post, a handle, and voila – ball turning tool.

.

Fine in principle, but are you familiar with the Cowells lathe ? : **LINK**

http://www.cowells.com/90me.htm

MichaelG.

[JasonBModerator @jasonb]

I wonder if the small Sherline one would fit

[Sam StonesParticipant @samstones42903]

Steve,

I meant to show this when your thread appeared.

It must have been back in the late 60's that I saw something like this in Model Engineer. I can't be sure.

I also had a piece of bronze bar from an earlier project which became the bearing and a means of gripping it under the ML7 tool post clamp.

As you would guess, a round cutter was inserted into the thing on the left.

It went out the door with most of my other equipment.

Regards,

Sam

[Author]

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