Mulling over a potential Pioneer key repair approach

[Dave Britten]

I've got a 32SII that's in pretty good condition, except some of the plastic hinges that hold the keys to the keyboard "skeleton" are broken. This leaves a couple of digit and operator keys that are pretty awful to use, as they float around and rock back and forth over the dome switch beneath.

Theoretically, could I take a cheap 10B, open it up, carve out that entire section of the keyboard (digits and four main operators), drop it into the 32SII (after similar key-removal surgery), and expect it to feel and function anywhere near ideally? I know the R/S key would be mislabeled as =, but I could either doctor it up, or just ignore it.

I'm familiar with the pitfalls of opening up Pioneers - or rather reassembling them afterward. Just curious if anybody has tried this kind of repair and what the results were before I go carving up my calcs.

I've also got a 32S with a keyboard that's in pretty good condition as far as the plastics are concerned, but with a few of the domes under the keys getting pretty mushy. Might also see if I can transplant the dome switch sheet from the 10B if I end up chop-shopping it.

[Dave Britten]

Shoot, it looks like the keyboard and front half of the shell are one solid piece, at least on the unit I've got. The key swap I had in mind probably wouldn't be feasible. I was hoping it would be more like the palmtops, where the keys are all on a separate, removable matrix.

[Katie Wasserman]

I've never tried that but I can't imagine that it would work. The entire hinged key section is a single molded piece that offers no obvious way to section it without it falling apart.

I think you have a much better chance of trying to fix the few keys that are broken by melting into the remaining plastic a small, thin, flexible piece of metal to serve as the hinge.

[aj04062]

I have a number of pretty toast 32SII fronts (bad domes). I could send you one if you're serious about the dome sheet transplant.

[Geoff Quickfall]

Ouch,

Even I haven't tried that one. And believe me, I have thought about it. You can remove the front bezel with a hair dryer,

See this article in the HP SOLVE:

Click on 'calculator restorations' under 'your articles' section. Scroll down and you will see the bezel removed from an HP42S exposing the plastic key panel.

Hp solve article

This would be your best access to repair the broken tabs.

Hope this helps,

Geoff

[Dave Britten]

(09-04-2014 04:16 AM)Geoff Quickfall Wrote:  Ouch,

Even I haven't tried that one. And believe me, I have thought about it. You can remove the front bezel with a hair dryer,

See this article in the HP SOLVE:

Click on 'calculator restorations' under 'your articles' section. Scroll down and you will see the bezel removed from an HP42S exposing the plastic key panel.

Hp solve article

This would be your best access to repair the broken tabs.

Hope this helps,

Geoff

Thanks, I was looking around for a few pictures of the keyboard internals last night but didn't find anything good. I think mixing and matching subsections of the keyboard just won't be feasible with the way they're built (i.e. very differently from the palmtops).

So the next question is what's the best way to repair broken key hinges? I've tried a hot glue gun (which works great for resealing the popped heat stakes), but it's not nearly precise enough and makes a mess of the keys.

[everettr]

(09-04-2014 10:41 AM)Dave Britten Wrote:  So the next question is what's the best way to repair broken key hinges? I've tried a hot glue gun (which works great for resealing the popped heat stakes), but it's not nearly precise enough and makes a mess of the keys.

I haven't faced this situation yet, but in similar situations I have had good luck with ShapeLock. See ShapeLock prototyping and repair plastic.

This stuff is much like hot glue, except it can be handled with bare hands while you work. It bonds to many other plastics when melted. I am not sure if this will bond with the key hinges; you must try and see if it sticks. I am imagining a small bit of ShapeLock on the end of a toothpick, under a hair dryer set so that the ShapeLock is molten, but with your hand and the key hinge warm but undamaged.

[Geoff Quickfall]

That is the question (Shakespeare).

When you buy articles at any store they come with those little plastic encased metal strips of spring steel. They are the things they have to demagnetized (I think) to allow the purchased article past the door detectors (magnetometers?).

In any case, inside the plastic strip is a perfect spring steel strip about a quarter inch wide and an inch long. They make perfect pendulum swing supports for clocks. They are also rigid spring steel.

I was wondering about shaping and filing it to fit, then epoxy it in place after you glue the broken ends back together.

Geoff

[Dave Britten]

(09-04-2014 04:17 PM)Geoff Quickfall Wrote:  That is the question (Shakespeare).

When you buy articles at any store they come with those little plastic encased metal strips of spring steel. They are the things they have to demagnetized (I think) to allow the purchased article past the door detectors (magnetometers?).

In any case, inside the plastic strip is a perfect spring steel strip about a quarter inch wide and an inch long. They make perfect pendulum swing supports for clocks. They are also rigid spring steel.

I was wondering about shaping and filing it to fit, then epoxy it in place after you glue the broken ends back together.

Geoff

Now that's a great idea. I'm going to have to remember to start saving those things from game/movie cases. I had no idea they put spring steel in them.