deskthority

Hey all,

Me again!

Just another IBM related query - does anyone know the rated switch life as it were of buckling springs? Writing a review on the Unicomp New Model M and I don't know too much about their longevity as such (of course, 35 years worth of constant input).

Any help would be appreciated!

Cheers,

Reece.

25 million key presses for the Model M's membrane buckling springs (which contrasts the 100 million for the Model F's capacitive buckling springs). This is true for vintage and Unicomp era.

sharktastica wrote: ↑

14 Sep 2021, 15:38

25 million key presses for the Model M's membrane buckling springs (which contrasts the 100 million for the Model F's capacitive buckling springs). This is true for vintage and Unicomp era.

do you know if its becasue of the membrane or the spring itself?

inozenz wrote: ↑

14 Sep 2021, 17:21

do you know if its becasue of the membrane or the spring itself?

Afaik, it's the membrane sheets that heavily reduced its lifespan.
In practice after 35-ish years though, they aren't usually the cause of death for these Model Ms... ahem cough rivets cough ahem

Bitteneite wrote: ↑

14 Sep 2021, 19:32

inozenz wrote: ↑

14 Sep 2021, 17:21

do you know if its becasue of the membrane or the spring itself?

Afaik, it's the membrane sheets that heavily reduced its lifespan.
In practice after 35-ish years though, they aren't usually the cause of death for these Model Ms... ahem cough rivets cough ahem

good thing there is something called bolt mod, that should increase lifespan significantly.

Bitteneite wrote: ↑

14 Sep 2021, 19:32

inozenz wrote: ↑

14 Sep 2021, 17:21

do you know if its becasue of the membrane or the spring itself?

Afaik, it's the membrane sheets that heavily reduced its lifespan.
In practice after 35-ish years though, they aren't usually the cause of death for these Model Ms... ahem cough rivets cough ahem

Personally, I think the worst design decision and one of the "causes of death" on the F is the foam sheet. I think the Fs are easier to work on, from that perspective.

When enough of a Model M's rivets are broken, the barrel plate can break apart in the folds between the rows of keys and it can no longer be bolt-modded.

On the M2 you can damage a spring if you seat a keycap wrong. I don't know if that is an issue on the regular Model M.

Findecanor wrote: ↑

14 Sep 2021, 22:06

When enough of a Model M's rivets are broken, the barrel plate can break apart in the folds between the rows of keys and it can no longer be bolt-modded.

On the M2 you can damage a spring if you seat a keycap wrong. I don't know if that is an issue on the regular Model M.

I have gotten springs to "fold over" a bit and needed my pin-tip tweezers to get them un-folded. You also can pull out the spring and put another in its place, using a toothpick. I'm not necessarily saying that the spring will stay in position ...

I still haven't done a bolt or screw mod, yet.

I'll definitely agree that the barrel plates are flimsy. I think I prefer the single barrel per hole on the Model F, even though you have to deal with that foam.

Findecanor wrote: ↑

14 Sep 2021, 22:06

When enough of a Model M's rivets are broken, the barrel plate can break apart in the folds between the rows of keys and it can no longer be bolt-modded.

If you have a ruined soldering iron around, you can easily patch up a cracked barrel plate.
It does need a bit of precision, but otherwise, it's pretty straightforward. (Self-plug to guide)

Findecanor wrote: ↑

14 Sep 2021, 22:06

the barrel plate can break apart in the folds between the rows of keys and it can no longer be bolt-modded.

It can still be bolt-modded, the screws will hold the pieces in place. There is no real reason that the barrel plate needs to be one piece anyway, the Model F has individual barrels after all.

And it can be easily glued if you don't mind the existence of a repair that is not visible when the keyboard is re-assembled.