15-30k RPM 7x12 Mini Lathe

Yeah, not really.. but I wanted to cut a section of brass rod to create 3 straight flutes, so I chucked a Dremel flexshaft handpiece in the lathe's
3-jaw and mounted the rod on the toolpost so I could advance the rod into the cutter in small but precise passes (using the compound feedscrew for passes and the crossfeed to increase the depth). The Dremel rotary tool motor was providing the high RPM.
This little sideways milling method was much more precise than any handheld work I could've done.
For indexing the rod around at 120 degrees of rotation for the 3 cuts, I used a small drill chuck secured to the back end of the rod (sticking out past the back side of the turret toolpost) and used the 3 chuck key holes as index locations.
Definitely sufficient for TLAR work.
--
WB
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On Fri, 4 May 2012 10:21:29 -0400, "Wild_Bill"

That's clever, but keep in mind that it's often done the other way around, using the lathe's bull gear as a fixed-value indexer. If your bull gear has an appropriate number of teeth you usually can get a variety of symmetrical steps around a circle.
I've used my South Bend to do that kind of thing several times. I hold the Dremel, or my old industrial-grade B&D die grinder, mounted in my milling attachment, although it could be rigged in the toolpost.
The clever Brit hobbyists have sometimes modified their lathes with a worm gear driving the bull gear to get pretty versatile indexing.
--
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Yep, kinda the backwards method, but quick as far as not needing to fabricate a proper sturdy holder for the Dremel handpiece.
Access to gears on a mini lathe (and numerous other models) is limited to one small gear at the left end of the spindle.
For utilizing the spindle for a 3-position indexing task, a surface of the jaws of the 3-jaw chuck should be adequate for equal spacing, or 4-jaw chuck for 2 or 4 positions.
As Jim W mentioned a while ago, a hex nut is sometimes a convenient divider reference.
--
WB
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On Sat, 5 May 2012 17:39:32 -0400, "Wild_Bill"

Yeah, there have been a number of clever ideas used to provide indexing on a a lathe spindle. One interesting one I saw used a set of three or four fine-toothed gears mounted on a faceplate, allowing a wide range of symmetrical divisions, located with a spring-loaded pin that was mounted on the headstock.
At that point it starts to become a gymnastic exercise, but it works, and it costs a lot less than the regular solutions.
--
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I haven't seen a method using the gears and faceplate arrangement, but I've seen a simple method mentioned at least several times, which is to make up an incremental scale to glue around the circumference of a chuck.. definitely a cheap method and good n'uff for certain projects.
--
WB
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