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
..........

15-30k RPM 7x12 Mini Lathe
 

On Fri, 4 May 2012 10:21:29 -0400, "Wild_Bill"
wrote:

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.

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.

--
Ed Huntress

15-30k RPM 7x12 Mini Lathe
 

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
..........


"Ed Huntress" wrote in message
...

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.

--
Ed Huntress

15-30k RPM 7x12 Mini Lathe
 

On Sat, 5 May 2012 17:39:32 -0400, "Wild_Bill"
wrote:

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.

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.

--
Ed Huntress

15-30k RPM 7x12 Mini Lathe
 

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
..........


"Ed Huntress" wrote in message
...

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.

--
Ed Huntress