Todays Topic from Panelman

Jay Jaeger cube1 at
Thu Nov 19 11:24:05 CST 2015

On 11/17/2015 2:03 PM, rod wrote:
> Thanks yes they do look similar. I'll download the data sheet.
> What I forgot to explain was the problem is not the switch itself but
> the additional part on top into which the two pivot pins locate.
> My policy is to produce form factor replacements. In this case the lever
> arm.
> If they can then be incorporated into other assemblies then good.
> Here the lever rotates about a pivot point formed by the two sides of
> the additional structure on top.
> A missing segment in the lower semi-circular part of the lever engages
> with the slide switch and moves it.
> So there being no known source of the switch with the extra part on top
> and not wanting to change the lever.
> What do we do? It would not have been feasible to make the top part and
> attach it, as its spring steel.
> Its horrible stuff to work with. Pretty much you are limited to die
> stamping it in a heavy press.

If the contacts are bad, then, after removal, perhaps you could unfold
the tabs that hold the fiber/phenolic piece with the contacts in it and
then swap that contact piece and maybe the switch post piece, and bend
the tabs back, keeping the original mechanical parts?


> They would have punched the shape and the holes out with a hardened die
> and then before or after spot welding it to an empty switch body hit it
> again with a folding die to bring the sides up.
> That would be too expensive to get set up. So I am looking at alternatives.
> Rod
> On 17/11/15 18:38, Jay Jaeger wrote:
>> On 11/17/2015 2:34 AM, rod wrote:
>>> Now to the slide switches themselves.
>>> They are mounted by the screw hole lugs having been slid into  a groove
>>> in two aluminum bars which in turn are attached to the PCB by pillars
>>> and screws.
>>> There are six connection pins on the bottom of each switch that go into
>>> holes in the PCB. (not all used) Switch replacement would be easy and a
>>> complete switch and lever sub module not too difficult. I hear a voice
>>> from the distant past saying 'Micro switches'
>>> Thats all for to-day
>>> Rod
>> The ones I have seen (on my PDP-8/L and PDP-12) are simple stock
>> old-school slide switches (definitely not Micro-Switch switches), that
>> typically look like this one:
>> (I did *not* check dimensions to see if this particular one is right or
>> not - there were standard size and miniature versions.  But the photo
>> looks about right).
>> JRU

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