[sebhc] punching hard sectored disk

[Dwight K. Elvey]

Hi
 I worked on my disk punch this weekend. I was able to make
a few disk. It works reasonably well but I'm not yet happy
with my locating method.
 I'm using an old SA400 frame. These are nice heavy cast
frames. I milled some blocks of aluminum to make the
punch and used a #38 drill bit as the punch. I did this
machine work on my tinky-lathe ( Shearline ). I used
a 100 tooth gear to index the locations for the punch
marks but somehow got the index location off a little.
I manually offset this and it seems to work. I'll fix
this before the final version.
 Right now, I have no mechanical detent for locating
the hole positions but expect to make a detent using
a ball bearing ball as soon as I locate a ball about
1/4" diameter. I currently use a pointer ( attached with
hot glue ) and a magnifier to locate where to punch.
I've made 9 disk that seem to work well but had 4 failures
( see note above about index location ). The disk
I'm using are known to have a bunch of bad ones so the
failures are not all caused by my punching.
 Most times the punch works well but just like Florida,
I get the occational hanging chad. I just take a pair
of needle nose and twist these off. It isn't the fasted
punch system. You need to do each hole independently but
does seem to work. It'll be faster once I get the detent
working to locate the hole positions.
 Once done, if someone has a web page that can host pictures,
I'll take some and send them.
Dwight


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