Umm - methinks you will have more problems threading 1/4 inch rods X up to
4 inches long than you will forming a 'bullet' nosed profile on the ends. Just what are you making? What tolerances? Post a drawing of what you are attempting and the folks here can steer you right.
Time to make or buy another tool. Called a ball turning tool or attachment in the US.
for an example see
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FWIW -- I buy from this supplier and find them to be very good to do business with.
Unka' George (George McDuffee) .............................. Only in Britain could it be thought a defect to be "too clever by half." The probability is that too many people are too stupid by three-quarters.
John Major (b. 1943), British Conservative politician, prime minister. Quoted in: Observer (London, 7 July 1991).
For the bullet nose - make a shaping tool - out of HSS and go slow and lube.
Martin Martin H. Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net NRA LOH & Endowment Member NRA Second Amendment Task Force Charter Founder IHMSA and NRA Metallic Silhouette maker & member
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snipped-for-privacy@mail.c> I need to thread one end of 1/4" diamter rods ranging in length from
unless you need very accurate nose, just use a file while it is rotating in the lathe to round it off - you might chamfer it first to reduce the filing, but with a small piece like this you can quickly make a nice smooth nose with a file - now, if you really want to buy another tool, go ahead.
Short answer -- yes, but like everything in machining much will depend on the operator, tooling, materials, etc.
The inexpensive ball turning tools are manually operated (power feed tools available for $$$) thus feed rates are under operator control.
Be reminded that consistency is not accuracy. If you require a specific radius +/- 0.0005 inches, then save yourself a bunch of grief and contract out to a cnc shop.
Accuracy from the simple manual ball turning tools will require careful setup with the centerline of the ball turning tool pivot
*EXACTLY* at the lathe center height [note the shim/spacer requirement] and at *EXACTLY* right angles to the centerline of the spindle. In use, the cross slide must be positioned
*EXACTLY* so that the tip of the tool is on the spindle center line. The more any of these factors deviates, the less exact the "spherical" surface will be.
More than likely, with a little care in set up, attention to tool grind/condition, and average operator attention, your results will be very satisfactory.
Unka' George (George McDuffee) .............................. Only in Britain could it be thought a defect to be "too clever by half." The probability is that too many people are too stupid by three-quarters.
John Major (b. 1943), British Conservative politician, prime minister. Quoted in: Observer (London, 7 July 1991).
Unless I just break down and buy one from Little Machine Shop, I think I may just make my own ball turning tool.(I've gotten some pretty good ideas from some books I have).
The reason is that I am also having difficulty finding someone who can repro video game joysticks.(The ones witht he ball-top handle). So I may have to just make them myself, and having a ball turning tool would be a necessity.
Ok - I did and it wasn't hard at all. Wished I had the BIG pro type - but I didn't need it.
On engineman1 and my web page - and along with my wife as well - we started a club for a while in Santa Cruz Ca. Long de funk, and the website was to vaporize several years ago, but hasn't :-)
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On this - you will find several. Select the first news letter and two are there. Later I build one using a 2" milling head.
Martin
Martin H. Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net TSRA, Life; NRA LOH & Endowment Member, Golden Eagle, Patriot"s Medal. NRA Second Amendment Task Force Charter Founder IHMSA and NRA Metallic Silhouette maker & member.
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