apple Lisa2. Keypads

Erik Klein classiccmp at
Fri Dec 24 11:01:03 CST 2010

On Friday, December 24, 2010 7:59 AM Ray Arachelian wrote:

> Oh, I see, these are pulls from another old keyboard.  Too bad.

Yep, those are pulls from older but not-as-old-as-vintage keyboards.
Mid-90s, typically.

The foam seems to be a better composition so hopefully it'll last longer.
What usually happens is that the foam degrades and the residue ruins the
Mylar. Regardless the "used" stuff probably has at least 20 years left
relative to the foams its replacing.  Hopefully lots more.

I've used it to revive two Sol-20s and have some stashed for my Lisas,
Compaq and two or three others when I get to them.

The DIY approach is a good one since we'll all need it someday.  I've heard
of folks using Mylar from anti-static bags to do the one end and overhead
projector transparencies to do the other.

The trick, then, is finding a foam for the middle that is the right
consistency, thickness and composition to work and last.

And, of course, cutting the circles properly.

Erik Klein - The Vintage Computer Forums - The Vintage Computer and Gaming

> Hmmm...ok, your letter has convinced me.  It SEEMS easy enough, and
> it's not like this has to be done immediately.  I can snatch a few
> hours here and there as time allows.  However I'm sure it will take me
> more than an afternoon or two so I'm not convinced it's "less trouble"
> (-: .  More satisfying and permenant in the end though maybe.  I'd
> certainly replace the foam as most of it is degraded really badly.

I suppose if you could build some sort of circular cutting device that
has the right diameter, it would go a lot easier, but that seems
difficult.  You'd need to find a metal tube of the right size and
sharpen it to a blade, then rotate it against foam glued to a
mylar/taped aluminum foil layer.  (Or against foam/taped aluminum
separately and then glue.)

I suppose mylar balloons might work if flattened and glued to a thin
stiff piece of plastic also?

> At work we have some largish corkborers for punching out agar plugs. 
> One of these MIGHT just be a suitable size, which should make the
> process a lot easier.

That would work.  Perhaps there's some dremel bit sets that would
include this kind of cutting tool?  I did find a round cutting bit in my
collection, but it's specially made to cut round holes in doors for
locks.  Way too big.  But if you can find the right sized tool, or make
the right sized tool it would work.   I did mine all by hand with an
Xacto blade, which is a bit boring and makes for rough work.  In some
cases the geometry of the aluminum rounds failed to work, etc.  But if
there was a tool to get them all to be the same shape/size, it would
work much better.

Something like the above might work, but I'm not sure about the diameter
- the 1" minimum this thing does is too big.

Hmmm, perhaps cutting a tin soup can, then sharpening the edges with a
file and curling it on itself until it's the right diameter on the sharp
end, but makes a funnel on the other end, then attaching the funnel end
into a wooden handle could make the right tool.  Problem is the edge
would need to be sharp and that kind of metal is a bit too soft.

> I'll let you know how it goes.  I'l probably get onto it in
> Mid-January after the holiday season.  I've a few family commitments
> before then.
> Much obliged for the advice.

Sure, anytime.  If you do find a tool, or are able to make one, let me
know the details of what worked so I can add it to the FAQ.

> Terry

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