The boring head ball turners are a nice practical way of doing the job. Much better than many of the designs out there on the web. With the boring head versions you get the fine diameter control that I get with mine.
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That's such a great pic from IoM Tony!
I'm presently traveling and don't have access to any photos from my Bultaco days in the mid '90s. That bike was really a treat and a privilege to ride, we had some great days at the track but we also broke a LOT of parts and watched some races from the pits.
It's ironic that your '74 bike had a monoshock and disc brakes but the "modern" version is a twin shock with a drum up front. You were ahead of your time in '74. Now, 44 years later you can't do the same things you were doing back then and be "period legal"
Sorry for the motorcycle related topic detour....
Cheers,
Tyler
steamingbill,
The boring tool I used is sharpened in a different manner than a normal boring tool used in a boring head or lathe. The cutting edge that is normally sharp has a radius along it's edge of about .030". The end of the bar is the equivalent of the top surface of a lathe tool and is the cutting edge. It is hard to explain. I have posted a picture of the tool set up in the lathe. And finally a picture of the batch of ball handles I produced with this set up for use on my Quorn tool and cutter grinder. Attachment 22563Attachment 22564
I need to see the tool on the inside of the ball (towards the headstock). I do not see how you rotate the tool; to get the ball.
Nice work by the way, I cannot wait until I am able to do something similar.
Ralph
Hi Ralphxyz,
I do not have that job setup so can't take a picture. That job was done over 10 years ago. The tool is on center front to back and is ground flat on the end. Take a good look at the operator end of the attachment and you will see a handle with a red knob and that is how it is rotated. Also you will be able to see two stops and a pin sticking out the operator end. That is how the arc of rotation is limited to get repeatable results on each successive part.
Wmrra13,
Thanks for the complement! The bearing is a standard 1" I.D. oilite bronze bushing and does the job nicely. Yes, it has a big red plastic ball on the end of the handle. Shame on me. I should have taken the time to do it right on that tool but I was in a hurry and had the ball on hand so I used it. I never thought anyone would ever see it.
That certainly looks rigid enough. Assuming that the cutting edge has suitable clearance and rake angles the only thing that comes to mind re your chatter problem is that maybe the rotation is too free. Some damping or friction in the rotation might well reduce the vibrations that are associated with chatter. Try making it stiff but smooth to rotate.