IBM buckling spring - heavy spring experiment

fohat · 18 Sep 2016, 16:31

Yesterday I was cleaning up my work bench and came across a spring. I do not know where I got it or what it came from, but it looked like just the right size for an IBM buckling spring barrel and not very stiff.

I installed it on the space bar and it felt wonderful! Using the crude "stack of nickels" for measure, it increased the actuation force from ~70 grams to ~90 grams. But it also reduced rattle/clatter and made the entire length of the space bar seem firmer.

The jury is still out on whether the improvement is worth the extra effort required to use the key hour after hour, and I would certainly not want it on every key, but the space bar feels great so far.

This spring has a diameter of about 14.5 mm (<9/16") and a height of just under 7 mm (<1/4") with very thin wire and just barely over half of a single full turn around the circumference - this is an unusual and "weak" spring.

Techno Trousers · 18 Sep 2016, 16:55

So this surrounds the barrel and adds extra effort at the bottom of the keypress? Interesting. I'd be interested to hear how you like it long term, and for long typing stretches. I agree that the space bar would be the only place I could use a little extra weight.

fohat · 18 Sep 2016, 17:10

Techno Trousers wrote:
So this surrounds the barrel and adds extra effort at the bottom of the keypress? Interesting.

Yes it surrounds the barrel, but no, it is in play all the way. That is why it reduces rattle/chatter from the start.

derzemel · 18 Sep 2016, 17:45

Looks like a spring used under a foam and foil keycap

Sent from fat fingers on small screen...

fohat · 18 Sep 2016, 18:03

derzemel wrote:
Looks like a spring used under a foam and foil keycap

That is possible, although I can't remember.
I doubt that I have ever had but maybe 1 or 2 foam & foil boards, long ago, and I promptly ditched them.

It has been a few years since I have even seen one, now I want to find out. There are probably at least a few people who would like to mod the space bar. The extra stability is as great a plus as the extra weight.

0100010 · 19 Sep 2016, 21:55

I seem to recall running into a spring like that with a Wheelwriter (if memory serves). It was around / under the spacebar barrel as well.

chzel · 19 Sep 2016, 21:59

I have one of these from a rubber dome Model M I had (it was under the spacebar, probably to assist the dome with the lifting), and have it on my SSK!