2 Apr
2010
2 Apr
'10
2:19 p.m.
On 2 Apr 2010 at 14:03, dwight elvey wrote:
Hi
I'm starting to make some mechanical drawing for
some 11 hole punch blocks that could be used for
any combination of auto or manual punching.
There is an ANSI spec, X3.163, that I'd like to
look at. The cheapest I've seen is $22 and I don't
want to put out that much for a few simple dimensions.
The one I have the most question on is envelope
thickness. For the 5.25 disk I've already figured
most of the rest ( or at least what I believe them
to be).
This is what I have so far:
Spindle hole 1.125 dia
index hole 0.10 dia
index relative to center of disk 1.00 radius
Spindle relief hole 1.5 dia
Thickness of complete disk ( not counting folds at edges ) about .070
In my experience, the hole size isn't as important as the placement
of the leading edge. Index/sector pulse widths vary by drive
manufacturer, so the trailing edge isn't used (by anyone that I know
of).
For whatever it's worth.
--Chuck