"mkr5000" wrote in message
...
I have a part being machined that calls for 2 captive studs to be
inserted and thought I'd try to put the studs in myself. They're
stainless, 8/32 about an inch long and require a .163 pocket
(partially drilled hole).

I thought that maybe I could build some sort of jig to keep them
straight and then tap them with a hammer?

OR--

Is there a small accessory or something that maybe I could use with an
arbor or vise? Any ideas?

Need to do them myself to save some time and money.




**Something similar I do: **
I set alignment pins in molds now by drilling the press fit and the slip fit
in both plates and using the slip fit side as a guide for starting the pin.
Then I just smack it with a hammer to start the pin. (Usually 18-8 into
6061) Since I cut the molds on the little CNC mill I usually cut a short
pilot hole and chamfer before throwing them on the drill press, but I could
drill and chamfer on the mill quickly enough if I had a different machine
with a tool changer. For me its faster and accurate enough to hand drill
(on the press) those features.


** A possible solution for what you do: **
I think for a threaded stud (I assume half threaded and half press fit from
your description) I might make a thread on bushing for the threaded half.
Then drill a hole in a piece of plate that is a nice slip fit for the outer
surface of the thread on bushing. Make the bushing longer than the
thickness of the plate. Use a plate substantially thicker than the press
fit portion of the stud. Chamfer the edges of the press fit hole in the
work piece to assure proper starting of the stud, also to prevent ridging
around the pin. Smack, press, or clamp as needed. When the face of the
bushing meets the work piece remove your guide plate, and unthread the
bushing.


** Comments: **
It's a pretty simple concept, but if you like I'll make you a quick sketch.
Refine of course for desired level of precision and accuracy. Variations on
the theme could be used for a stud that is only partially threaded on the
exposed end etc.

If you have multiple studs you might make your guide plate as a template for
all of them instead of just one at a time. Obviously not practical for
multiple studs going into planes at different angles or surfaces at
different levels. Possible though if production numbers are high enough to
justify a special jig.

For a little ease of removal cut a bolt head on your drive bushing. For
work piece protection if necessary pad work piece face with leather or
rubber. Glue to drive bushing maybe? Maybe machine an acetal or HDPE
bushing for the work piece face of the drive bushing?

By drilling and threading your drive bushing all the way through you might
be able to use a set screw from the drive end (hammer side) to set and/or
adjust your drive depth easily.