I have need, from time to time, to replace small plastic fiberoptic
rods used for gun sights. The factory rods have a small rivet-type
head on each end of the rod for retention. Mulling it over, I figure
that maybe using friction and spinning the head on would work. To do
that, I'd need a highly polished spherical cavity on my spinner. I've
not had great success producing same in the past, this would be
probably between 2 and 4mm across. I've come up with a methodology
that will probably work. I'd either make up a D-bit with a
hemispherical end of the proper radius(probably 3-4x the radius of the
fiberoptic rod) or use a carbide burr in a micro die grinder/Foredom
handpiece to produce the shallow cavity in the end of the tool. I'd
then use a tungsten carbide ball and use that in conjunction with a
bench vise or press to produce the surface finsh I want. Lee uses
something similar to produce lead ball molds for blackpowder shooting.
I'm considering using something like 1/4" brass/bronze rod that I've
got sitting around for tool stock and using a pneumatic micro die
grinder for driving the tool after it's made becuase it can be
throttled way down. If I end up making up an alignment jig, it's would
be simple to use a V-block mount on the cylindrical die grinder body to
mount it to the jig. Anybody ever done something similar?

Stan

wrote:
I have need, from time to time, to replace small plastic fiberoptic
rods used for gun sights. The factory rods have a small rivet-type
head on each end of the rod for retention. Mulling it over, I figure
that maybe using friction and spinning the head on would work. To do
that, I'd need a highly polished spherical cavity on my spinner. I've
not had great success producing same in the past, this would be
probably between 2 and 4mm across. I've come up with a methodology
that will probably work. I'd either make up a D-bit with a
hemispherical end of the proper radius(probably 3-4x the radius of the
fiberoptic rod) or use a carbide burr in a micro die grinder/Foredom
handpiece to produce the shallow cavity in the end of the tool. I'd
then use a tungsten carbide ball and use that in conjunction with a
bench vise or press to produce the surface finsh I want. Lee uses
something similar to produce lead ball molds for blackpowder shooting.
I'm considering using something like 1/4" brass/bronze rod that I've
got sitting around for tool stock and using a pneumatic micro die
grinder for driving the tool after it's made becuase it can be
throttled way down. If I end up making up an alignment jig, it's would
be simple to use a V-block mount on the cylindrical die grinder body to
mount it to the jig. Anybody ever done something similar?

Stan

Stan, look at some of the jewelry supply websites and look for a dapping
die. They are a series of graduated semi-sperical depressions used to
make 1/2 of a bead or a domed form in non-ferrous metals.Some can be had
for a cheap price.
Michael

wrote in message
oups.com...
I have need, from time to time, to replace small plastic fiberoptic
rods used for gun sights. The factory rods have a small rivet-type
head on each end of the rod for retention. Mulling it over, I figure
that maybe using friction and spinning the head on would work. To do
that, I'd need a highly polished spherical cavity on my spinner. I've
not had great success producing same in the past, this would be
probably between 2 and 4mm across. I've come up with a methodology
that will probably work. I'd either make up a D-bit with a
hemispherical end of the proper radius(probably 3-4x the radius of the
fiberoptic rod) or use a carbide burr in a micro die grinder/Foredom
handpiece to produce the shallow cavity in the end of the tool. I'd
then use a tungsten carbide ball and use that in conjunction with a
bench vise or press to produce the surface finsh I want. Lee uses
something similar to produce lead ball molds for blackpowder shooting.
I'm considering using something like 1/4" brass/bronze rod that I've
got sitting around for tool stock and using a pneumatic micro die
grinder for driving the tool after it's made becuase it can be
throttled way down. If I end up making up an alignment jig, it's would
be simple to use a V-block mount on the cylindrical die grinder body to
mount it to the jig. Anybody ever done something similar?

Stan

Wow. I think maybe you are making it more difficult than it needs to be.
The normal way
to get that nice shiny half dome end on a chunk of fiber optic rod in a gun
sight is with a
butane lighter. Slip a chunk of rod through the hole. Leave about one
diameter sticking
out. Less for a smaller diameter end, more for a larger one. Wave the
flame of a lighter at it.
It will melt into that perfect half globe of plastic. No polishing
required. If you want to make up
a few with one end done for spares, just drill an appropriate hole on a
scrap of aluminum.
I use 1.5mm fiber optic for front pistol sights. A 1/16" hole is just
right.

Must be you get cleaner burning butane than I do, any time I use a
butane lighter or midget torch on plastic for polishing purposes, I end
up with soot embedded. On the other hand, I do have a nifty hot-air
tip for one of my butane soldering irons, I might just try that out if
I can dig it out from where the tool monster has it hid.

The inserts don't get busted in use so I don't need spares, red is
absolutely useless for a sight color for me and that's what most fiber
optic sights come with. So I've been busy converting them to green,
which works better.

Stan

wrote in message
oups.com...
Must be you get cleaner burning butane than I do, any time I use a
butane lighter or midget torch on plastic for polishing purposes, I end
up with soot embedded. On the other hand, I do have a nifty hot-air
tip for one of my butane soldering irons, I might just try that out if
I can dig it out from where the tool monster has it hid.

The inserts don't get busted in use so I don't need spares, red is
absolutely useless for a sight color for me and that's what most fiber
optic sights come with. So I've been busy converting them to green,
which works better.

Stan


There is a bit of technique involved. It's especially fun when you are
doing it between stages
at an IPSC match, standing in the rain with the wind blowing. I do bust a
few in use, usually by getting too close to a port or barricade and whacking
the front sight from recoil. There is a discussion on fiber optic sights
going on now over at www.brianenos.com Some good info there. I've tried
both the red and green. Either one works for me, but I trend toward red.

Bill

On Mon, 03 Apr 2006 13:53:49 GMT, "Bill Marrs"
wrote:


wrote in message
roups.com...
Must be you get cleaner burning butane than I do, any time I use a
butane lighter or midget torch on plastic for polishing purposes, I end
up with soot embedded. On the other hand, I do have a nifty hot-air
tip for one of my butane soldering irons, I might just try that out if
I can dig it out from where the tool monster has it hid.

The inserts don't get busted in use so I don't need spares, red is
absolutely useless for a sight color for me and that's what most fiber
optic sights come with. So I've been busy converting them to green,
which works better.

Stan


There is a bit of technique involved. It's especially fun when you are
doing it between stages
at an IPSC match, standing in the rain with the wind blowing. I do bust a
few in use, usually by getting too close to a port or barricade and whacking
the front sight from recoil. There is a discussion on fiber optic sights
going on now over at www.brianenos.com Some good info there. I've tried
both the red and green. Either one works for me, but I trend toward red.

Bill

I prefer robins egg blue for insert color. For me..it works
marvelously well..and Ive tried all different colors.

Gunner



"A prudent man foresees the difficulties ahead and prepares for them;
the simpleton goes blindly on and suffers the consequences."
- Proverbs 22:3

I prefer robins egg blue for insert color. For me..it works
marvelously well..and Ive tried all different colors.

Gunner



What's your source for robin's egg blue? Most of the "blues" I've seen
were more of a violet.

Bill

On Mon, 03 Apr 2006 20:39:51 GMT, "Bill Marrs"
wrote:

I prefer robins egg blue for insert color. For me..it works
marvelously well..and Ive tried all different colors.

Gunner



What's your source for robin's egg blue? Most of the "blues" I've seen
were more of a violet.

Bill

I was getting it from Lees Red Ramps

Gunner



"A prudent man foresees the difficulties ahead and prepares for them;
the simpleton goes blindly on and suffers the consequences."
- Proverbs 22:3