Ball turning jig

[The Bowler Hatted Turner]

I normally turn balls by hand/eye and can get them quite good if I can take my time but I am negotiating a commission that will include several balls that all need to be exactly the same size . So i am trawling the interwaves just looking at ball making jigs that I can cream ideas from. If I'm going to make a jig it needs to be a good one. And I saw this which impressed  me somewhat.

 www.youtube.com/watch?v=UNCcghr4cgw

Not sure how to make it a link but I'm sure someone will.
Probably the best made jig of it's type that I have seen so far.
Regards
John BHT

[Mark Sanger]

Hi John

Looks good. Have you seen this one, I know George has one and he says it is great, solid and works very well indeed.

http://www.ebay.co.uk/itm/WOODTURNING-LATHE-100mm-BALL-TURNING-TOOL/290973760132?rt=nc&_trksid=p2047675.m1851&_trkparms=aid%3D222002%26algo%3DSIC.FIT%26ao%3D1%26asc%3D74%26meid%3D1209134442289096501%26pid%3D100005%26prg%3D1048%26rk%3D3%26rkt%3D4%26sd%3D290973481327%26

Also I am sure you are aware how to do it by hand by turning through 90 deg. I saw this video and do mine like this now as it is quick and does not take time setting up ( or coast anything).

http://www.youtube.com/watch?v=3lConTQ-cUw

[woodndesign]

Well done Mark,  Alan sums it up just perfectly, his rechucking is better that trying to mount in a jam chuck, the keeping the line means you are truing to what is already round, I've seen it done to a scored line to the needed diameter, then it need a little work to finish, but retain the correct size.

In short by the time you've rough turned, sized and taken the corners off on each blank, then set up a jig, which you need to make or buy first ...  just to continue the turning is the way to go, well I've done them that way, it's in using the jam chuck things need to be true and it's only working so far on a face, plus popping it out the chuck.

And should the Balls need the be for the order, traditionally hand turned, would this be using a copy jig.

Mark good to read you're on the road too fast recovery.. then can't keep a good man down for long, take care in the coming cold workshop.

Cheers   David

[The Bowler Hatted Turner]

Hi Mark,
           thanks for that. We all know George is rolling in money so he can afford it!!
Seriously though, I have heard they are very good and perhaps in time I may be able to get one but for the time being I will have to make do with what I come up with.
The down side of this jig is the inability to turn a complete ball unless the tool holder is reduced to a "C" section, but this may have the effect of introducing chatter. I normally hold them in a chuck and turn them to a pattern(looking for light shows where to cut the next bit)But I do want these ones to be really spot on for shape and size.
Regards
John BHT

[Mark Sanger]

Glad it is of use. I always look for the most simplest ( and most cost effective) route and not having to spent money is good with me. )

Dave Thank you, I am certainly much better, still coughing my guts up throughout the day but at least I can work now. The doc says I will slowly cough less and less over the next month or two before it totally clears up.

 

[woodndesign]

Hi Mark,
           thanks for that. We all know George is rolling in money so he can afford it!!
Seriously though, I have heard they are very good and perhaps in time I may be able to get one but for the time being I will have to make do with what I come up with.
The down side of this jig is the inability to turn a complete ball unless the tool holder is reduced to a "C" section, but this may have the effect of introducing chatter. I normally hold them in a chuck and turn them to a pattern(looking for light shows where to cut the next bit)But I do want these ones to be really spot on for shape and size.
Regards
John BHT

Hi John,  If you should get into a habit of making Balls ....  How about checking out Bob Chapman's device ...  http://www.bobchapman.co.uk/_6__ball_jig.pdf .... it's along the lines of what you need and some parts of it you may find cheap as scrap.

Form the video, the large bulk of the jig limits as you consider the swing and he commented on the need to be able to relocate the lock knob/screw at each pass, looking close at what the video showed or not in that case, he's used a long drive, as well as having the tailstock quill fully extended for the jig to clear the headstock/tailstock in both directions.

He's also using the jig to turn off the corners ... at that rate if it's a 6" cylinder/ball, the jig clearance across the corners would be 8.5" not including the tool protruding as well, it's likely by the time the ball gets down to size, the proruding long tool could well introduce chatter with a round tool in scraper mod. There is not a follow up with the tool he was about to change too, or the completion of the ball .. did I notice another jig in the distances of the shot, maybe he's still developing the jig as we do, as we go along.

Best of luck on the commission and have fun.

David

[Eric Harvey]

you could always copy the design in plywood to fit any sized lathe.