Significant variation in Woodstock keyboards?

[Michael Meyer]

I received another "broken" HP-21 in the mail today. Fresh batteries and it works perfectly. This one is nice, with no corrosion whatsoever on the springs, contacts, circuit board. But I notice that the entire keyboard is really "soft"-- not just a few well-worn keys. I have other Woodstocks with almost ridiculously stiff and crisp keyboards... like some of my Spice series machines. And all my Woodstocks vary significantly in keyboard "stiffness"... and now that I've noticed this, I don't believe it has anything to do with how used the calculators were... you'd expect them to vary more within the same calculator, if that were the case.

What do you think accounts for this significant variation, one calculator to another... I have another HP-21 with very stiff keys!

[Walter B]

Woodstocks open easily. So, if you want to know, I'd suggest opening those two. Then check for significant differences.

Edited: 23 Mar 2010, 1:30 a.m.

[Michael Meyer]

Of course, I've opened all of them... to repair, swap chips, clean, etc. First thing I did with the new one was to soak the keyboard all day in soapy water then a good rinse and dry. Looks and works great.

Visually, the keyboards look the same, regardless of their tension. Since they're heat staked, the only ones I've torn apart were corroded. I'd like to avoid taking 2 of them apart just to answer this question if someoneone else on the forum has some insight and more experience.