"Bob La Londe" wrote in message
news
I've got a project that needs to be indexed to drill a bunch of
holes. Its 3D part of course so part of the initial machining is to
leave it "mountable." I have an idea worked out, but it has to be
supported at both ends. I was thinking two cheap spindexers face to
face would work. The work piece is machined with a radius slot in
each end that can be clamped to a pin mounted in each spindexer.
Yes, I know. You all have a better way, but this is the way I am
going to do it.

Now once you learn a trick you are sure to want to do it again.

I can clamp the two spindexers to the table with a lathe truing bar
between them, and get them dialed in straight to the machine I am
pretty sure. It will just be tedious and time consuming, but after
I figure out how to deal with any flex in the setup it shouldn't be
much worse than truing up a vise. Should be able to get within a
half thousandths over its length.

That's fine for one job, but I'm making a single prototype piece.
I'll want to get the indexers off the table and out of the way when
its done. Of course if the customer likes the prototype I'll be
making a bunch of them over time. So I'll need to throw them on the
table and take them off regularly. I have enough clearance on my
knee mill I could mount them in my vises.

No comes the problem. They will need to be re-indexed to the
machine every time they are used. The front and the bottom are the
only reference surfaces. The sides of the base appear to be as
cast. I looked at the slight step up to Phase II indexers, but they
don't look to be any better. In fact to find an indexer with more
good reference surfaces the price jump is substantial. Well the
quality of the indexers is much better too, but to much for the
prototype part they will be used to produce. I'd like to mill off
the sides of the base so they are square and perpendicular... not to
hard... but also equidistant from the center line of the indexing
body in a mirror relationship to its counterpart... I have no
clue... , so I could just drop them in the stepped jaws of the mill
vises when I need them.

Actually I just had an idea. Cut the minimum to square up the base.
Flip and mount. Mount a work piece in each. Measure the offset.
Remove the offset from opposite sides of each base. This thought
JUST came to me, so I am sure there has to be something wrong with
the idea. Hit me.

Flame suit on.


I have two spin indexers facing each other on the table. It would be
easy enough to clamp them on opposite ends of a stiff 1" rod, spaced
far enough apart to hold the center of the rod in the vise with the
indexers base-up, but then I don't have enough support for the bases
to risk milling them. Threaded rod screwed into and protruding above
1-2-3 blocks might work(?). I'd be happier with angle plates bracing
the side the end mill pushes toward.

If they could be supported well enough a shallow lengthwise slot for a
key that fits a table tee slot should repeatably locate them in line.
The slot wouldn't have to be accurately centered, it's enough that the
rod in the vise ensures that both bases were slotted at the same
offset.
-jsw

-jsw