MadModder
Gallery, Projects and General => How do I?? => Topic started by: AcieraF3 on August 14, 2012, 11:49:15 AM
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I have build a Bedair-type ball cutter to fit my Boley 5LZ lathe. It works like a charm but I was not able to cut a real ball, they are all a bit olive shape. I did some research on this forum but I did not found a clear answer how to adjust the cutter and maybe the other axes of the lathe, to produce this much wanted nice real ball.
Anybody some good tips?
Teun :Doh:
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If the pivot centre of the ball cutter is centred with the work piece, there is no reason for a olive shape.
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attached some photo's of the ball turner attached to the lathe. Material is cast iron and alluminium for the cutter holder. I will redesign the holder and will use more rigid metal for it.
There are two examples of balls I made. The first one is a little pointy and the second has a flat top. What went wrong? Any tips?
Teun :worthless:
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Have a look at Frank Ford's site here:
http://www.frets.com/HomeShopTech/Projects/SafeHandles/safehandles.html
Scroll down to see how he sets up his ball turner to give an exact ball
Bill
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Hi Bill
thanks, seems easy enough! I will try it and post the result.
Cheers,
Teun
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A more accurate way of centering the radius attachment to the axis of the spindle is to chuck a piece of bar stock or the piece you want to turn into a ball, and check that the tip of the cutter is equidistant from the front and back side of the bar stock when rotating the radius attachment front to back. Once you have found center, zero your cross slide. Now you can install the work piece adjust the tool bit until it just touches the work piece, while the cross slide remains on the zero setting. Back off the cross slide and start cutting the ball. Stop advancing the cross slide when you reach zero, else you will end up with something other than a ball.
If you are attempting to cut a radius (convex or concave) that is not to be centered to the axis of the piece, then center the attachment per above, then move the cross slide in our out using the dials to center the attachment to the axis of the radius. Always zero the cross slide at the axis center. Then last step is to adjust the cutter for the radius you desire. As before, advance the cross slide until you reach the zero or axis center.
I don’t know how good the instructions are for most radius cutting attachments, but if you google Hardinge radius attachment operating manual (which is the attachment I have), you’ll find the process fairly well documented. The process is materially the same for any radius attachment though the adjustment methods differ between the tools.
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Thanks, this is a very comprehensive answer. I will google the Hardinge manual right a way. :beer:
Teun