The Museum of HP Calculators

HP Forum Archive 15

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Pioneer Creaking
Message #1 Posted by Neil on 18 Mar 2006, 4:16 p.m.

I've built up a collection of pioneer calcs. I've noticed that with a few of them, I can press the 2 case halves slightly closer together with my 2 fingers going around the edges of the calc, at some particular spots, with a consequent creaking sound when I press, or pinch together, and then release. On one of my calcs, there is even creaking when I press on one of the keys nearest the lefthand side, and this is due to the 2 case halves being able to move against each other at that point. I'm just wondering if this could mean that the calcs with this creaking may end up failing earlier than those where the 2 case halves are completely fixed, with no movement? This question is directed at the guys who have experience of opening and repairing pioneers.

      
Re: Pioneer Creaking
Message #2 Posted by Eric Smith on 18 Mar 2006, 11:44 p.m.,
in response to message #1 by Neil

Sounds like you're talking about Clamshells rather tha Pioneers? E.g., 18C, 19B, 19BII, 28C, 28S?

            
Re: Pioneer Creaking
Message #3 Posted by Neil on 19 Mar 2006, 10:31 a.m.,
in response to message #2 by Eric Smith

Hi Eric,

No, I definitely mean Pioneers eg 17bii, 14b, 27s etc. If you take a look at a pioneer, you can see that there is a seam all the way around the sides. On a few of my calcs, there is some flexing at the seam when trying to pinch both calc halves together, with a consequent creak. On other calcs, there is no flexing at all. They are solid. My guess is that this flexing is nothing, it will never cause any keys to fail prematurely, but I was curious enough to ask the question.

                  
Re: Pioneer Creaking
Message #4 Posted by Eric Smith on 19 Mar 2006, 4:24 p.m.,
in response to message #3 by Neil

I misinterpreted what you said about pressing together the two case halves. Also, it is common for Clamshells to be a bit creaky.

      
Re: Pioneer Creaking
Message #5 Posted by Karl Schneider on 19 Mar 2006, 12:34 a.m.,
in response to message #1 by Neil

Neil --

I have two calc's made in Singapore during 1993 -- an HP-17BII (Pioneer-series) and an HP-48G ("stretch Pioneer"). Both of them creak in the same fashion, but have yet to cause me any problems.

-- KS

Edited: 19 Mar 2006, 12:35 a.m.

            
Re: Pioneer Creaking
Message #6 Posted by Neil on 19 Mar 2006, 10:34 a.m.,
in response to message #5 by Karl Schneider

Hi Karl,

Did you get your calcs in the early 90's (1993) and have you used them regularly ever since? If so, then that's certainly evidence that the creaking and flexing is a non-issue.

      
Re: Pioneer Creaking
Message #7 Posted by Randy on 19 Mar 2006, 10:52 a.m.,
in response to message #1 by Neil

The creaking is most likely caused by several locking pins that extend from the front half into the back half. The back case has molded tapered sockets, I suspect the idea mechanically was for the pin to wedge tightly into socket helping to the hold the edges of the case together. In practice, probably due to material shrinkage once molded, its a less than perfect way to join the halves.

With the help of the Museum's 42S photo, the location of the pins are circled in white.

            
Re: Pioneer Creaking
Message #8 Posted by Neil on 20 Mar 2006, 2:18 p.m.,
in response to message #7 by Randy

Randy,

Thanks for the detailed info. So does this basically mean that the whole keyboard assembly is not affected in any way by the case halves being slightly loose / creaky?

                  
Re: Pioneer Creaking
Message #9 Posted by Randy on 20 Mar 2006, 4:59 p.m.,
in response to message #8 by Neil

I see no reason why it would bother the calculator in any way.

Also, FWIW, *very early* Pioneers did not have the pins, they used a scheme like that later used on 48's - bent metal tabs and small plastic tabs that are supposed to interlock. IMO, less than perfect in practice as creaky 48's are pretty common.


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