A Modified Indexer for the Unimat
Ronald E. Thompson
problem is they aren't made any more, and they are getting scarce
and expensive. I considered making the main body to sell, but the index
pin is intricate and has many small parts.
It would be hard to make a profit if my time was
to be worth anything.
And then there is the fact that a full set of index plates was costly,
In talking with other people on the Unimat Yahoo
group, an idea was
born. Why not eliminate the expensive parts, and create a new screw
The idea is to make it work like
a rotary table, but retain
the size of the work envelope and the ability to use other Unimat
parts, like the 3 jaw chuck and the round t-slot table.
Below is the inital concept rendered in
close, but not quite there. It still needed a way to take up the lash
in the worm gear, and a way to indicate the amount of rotation of the
input shaft. Below is a more refined concept. The casting would be cut
with a bandsaw or slitting saw to separate the worm carrier so it could
be adjusted and the input shaft now has an indicator ring.
all sounds good, but a prototype needs to be made to prove the concept.
Larry Collier of Lexington Kentucky works for a company that has a 3D
printer and offered to make a 3D printed plastic
model from the Solidworks model. I made the changes needed to
make it into a casting pattern and Larry gratiously printed it and
shipped it to me free of charge. You
can click on a photo below to see a much larger version.
I was concerned the 3D plastic
model would show ridges that would make it impossible to pull from the
casting sand without destroying the sand mold.
there are some ridges, I
think it's smooth enough to work as a pattern.
all for now. I hope to
cast one or two soon.
Visit my main page here: Plansandprojects.com