N Cook wrote:
Ron(UK) wrote in message
...
N Cook wrote:
Ron(UK) wrote in message
...
N Cook wrote:
Hamad bin Turki al Salami wrote in message
...
I deal with a number of vintage devices, refurbishing and reselling
them. One of the annoyances I have is dealing with missing or broken
buttons (and knobs, dials, etc.). As silly as it may seem, something
like a missing button cap, that has no functional effect on the
device,
can dramatically lower the value and salability of a device.

Now, if there's an electronic component that's broken, I at least
know
how to look for it, by its electrical specs or even its model number.
However, if I need to replace a button, I'm lost. Buttons rarely have
useful identifying markings on them. And there must be thousands of
buttons on the market, with many variations on shape, size, physical
characteristics, ..., from dozens, maybe even hundreds of
manufacturers.
At least, so it seems from the searches I've attempted. I've been
unsuccessful at finding replacement buttons and such, except in the
cases where I had the luxury of the specific manufacturer and part
number.

How do you find a replacement button? Are there any tricks to it?
Any hints appreciated.


From tips files on URL below

For making reasonable looking copies of old bakelite or
unconventional equipment knobs.
Requirements:-
snipped for brevity

Something you might possibly not be aware of is a material called
Polymorph.
It`s a white nylon like substance supplied as granules, which melt in
hot water (below boiling point) into a transparent mouldable mass. It`s
cool enough to mould by hand and when fully cooled, immensely tough -
virtually unbreakable in fact - it machines very much like nylon, and
can be drilled and tapped. Ideal for prototyping parts and for making
replacement knobs and handles and for modelmaking.

I got mine from Rapid Electronics

Ron(UK)
New one to me, looks interesting

http://www.rapidonline.com/productin...=Educational+P
roducts&tier2=Graphics%2c+Art+%26+Design&tier3=Mat erials&tier4=Polymorph&mod
uleno=34444

30 deg C is too low for practical uses though.
What do you mean too low for practical uses? at room temp it`s rock
hard. You wouldn't make a valve base out of it, but that`s not what it`s
for.



I wonder if it takes colourants/additives.
You might be able to kneed in some kind of colouring, possibly a
powdered nylon dye

Unfortunately probably no use with moulding rubber as that melts at
about
100 deg C
Works nicely with pourable silicon tho

"Polymorph is one of a new generation of polymers with all the
characteristics of a tough, machinable engineering material, yet it fuses
and becomes easily mouldable between 30°C and 62°C."
from the rapidline URL before.

Reading up about it , it is supposed to be related to hot-melt glue.
Hot-melt material is remeltable so can easily take different colours on an
ad hoc basis. Is polymorph one-time-use ? so it will not remelt if exposed
to 30 to 62 . Is polymorph one-time-use ? so it will not remelt if exposed
to 30 to 62 °C ?

You can remelt polymorph over and over again with the same results.
Obviously it`s not intended to be used for making something that would
be exposed to heat.

There is a pourable version now that you freeze to harden. I`m not sure
what the uses of that are.



I assume it is a harder resulting material than hot-melt glue stick.

It`s a lot harder, think of screwdriver handle hardness. It has a
slightly soapy feel to it. In fact, it`s great for making special tool
handles.

Order some and try it, it`s cheap enough.

Ron