geekhack
geekhack Community => Keyboards => Topic started by: simplexity on Fri, 11 November 2011, 06:22:25
-
What is the average amount of keystrokes until a Model M (or any Buckling Spring) stops working?
Thanks.
-
I think we have yet to find out.
-
I think we have yet to find out.
Shouldn't there be an estimate though?
-
If you take the trustworthy hitchhiker's guide to the galaxy as reference it should be 42! :gossip:
-
I'm not sure what you mean by "wear out".... as far as anyone can tell, they'll stay functional for virtually forever. As for wear, the actuation force gets lighter over time, and it starts to "ping" more. Personally i like the lighter actuation force, and have learned to deal with the ping.
So in simple terms... like the sun, it will wear out eventually but not soon enough for you to worry about.
-
And then when it becomes too light, or too pingy, you do a bolt mod, replace springs and you keep using it forever.
-
I have an IBM model M and it's still working. So at least 30-50 million strokes, maybe more.
-
I think Model M doesn't really suffer from the problem of failing switches. The main switch is just hollow with a single spring in it, very little in the way of moving parts. If anything I would say one day in the far off future you may want to just buy a new set of springs for all keys and replace them, and you will be good to go.
-
If you bathe your M in bleach, you can get it to die immediately!
Seriously though, I have units recieved from a former mental institution (ie- used heavily by the mentally disabled!) On one unti, some of the PBT caps are worn flat and there are cracks to the casing. The springs still feel brand new. Ms last forever!
-
I have asked this before and never heard an answer:
How can you evaluate springs?
I have a big jar full, and want to pick the best ones for my next project. Besides checking to see if they are stretched, bent, or rusty, is there any other way to test them?
thanks
-
Most Model M's never get shiny keycaps. Heavily used units have halfway shiny keycaps.
This is the closest thing to an odometer for the Model M.
Last year I bought a used unit with some keys that were just lapidary, perfectly smooth. Still worked fine.
It'll outlast you.
-
Unlike most others, these things last forever, especially if you're willing to do a little maintenance. For instance, the Model F I'm currently using is from 1984. There were a few rusty springs that worked just fine, but felt a bit different, so I replaced them with springs from a different F (XT).
So yeah, almost as old as I am, heavily used/abused and still going strong.
-
we should put a paypal fund together and pay a teenager 10 bucks an hour to find out exactly how many presses it takes. Just press 1 key for 8 hours a day, logging presses.
-
we should put a paypal fund together and pay a teenager 10 bucks an hour to find out exactly how many presses it takes. Just press 1 key for 8 hours a day, logging presses.
Or we could use a machine.
-
Or we could use a machine.
I was actually interested more in the social aspect of the experiment. How long before said teenager gets bored and spends his 80 dollars on zima?
-
we should put a paypal fund together and pay a teenager 10 bucks an hour to find out exactly how many presses it takes. Just press 1 key for 8 hours a day, logging presses.
Economic stimulus idea of the week!
-
we should put a paypal fund together and pay a teenager 10 bucks an hour to find out exactly how many presses it takes. Just press 1 key for 8 hours a day, logging presses.
I'm your teenager.
-
Perhaps I should re-phrase my question.
Although the consensus seems to be that Model Fs and Ms last pretty much indefinitely, there have been references to "old" and "tired" springs. I understand that metal eventually "fatigues" although steel is far less prone to do so than aluminum.
If the suggestions to replace older IBM springs with newer Unicomp springs is because the Unicomp springs are inherently different, that is one thing.
But if it is simply replacing older with newer, then what has happened to the older ones?
I actually have several batches of springs segregated by origin, but they all look pretty much the same.
-
Yes, old springs can feel mushy. Except sometimes they feel fine.
This is subjective. Caution, McRip effect.
A force-curve graph could measure the "mush", perhaps. You'd need that, plus a bunch of Model Ms that were modded with odometers when new and then sent out into the field for 20 years, to get data on this. That would be awesome!
Unicomp will probably do this analysis and publish the results when they release the new SSK.
-
Thanks. I will get out my magnifying devices and do that.
But my ****, although not as secure as it once might have been, will not be loosened by observing the condition of Reagan-era plastic parts.
Edit: Ripster I have come to expect obtuse dry humor from you. Last night I was assuming that the "bridge" was part of the spring mechanism. You were talking about actual bridges that actual cars drive over! Duh! silly me
-
How about M's membrane? Membranes do wear out, I did that on non-BS keyboards.
-
Due to the way membrane is used in Model M it's far less prone to failures than ordinary rubber domes.
Also I think springs get mushy due to improper storage (with keys being pressed by something laying on top of them for example) rather than normal use.
-
So who here has legitimately worn out an IBM Model M? Ah, right. I'm the guy who did that.
The rivets popping are usually what I'd describe as a non-critical issue; they don't actually break anything, and they're repairable. Same for broken springs; they are replaceable with some effort, and a bit of lithium grease can extend their life tremendously. To actually wear out an IBM Model M requires, shall we say, a lot of typing. How much typing? I'd honestly guesstimate somewhere around 40K words per day over 12 years when averaged out. If we crunch those numbers, we get:
280,000 keystrokes per day (~40K words @ 7 keystrokes average.)
102,200,000 keystrokes per year
1,226,400,000 total keystrokes over 12 years.
Over these 12 years, you will go through several sets of keycaps and at least one cable due to chair or pet. You may or may not go through an LCD board, depending on specific model and usage patterns - if you do a lot of LED toggling, it's likely. So, let's call it 1-2 billion keystrokes to wear out a Model M to the point where it's more or less completely spent and not worth rebuilding.
If you wanted to get a solid number for certain, you'd want to talk to a lab about a mechanical repetition test. I forget the name of the specific device, but it basically goes back and forth across the keyboard simulating keystrokes and verifying output until something breaks.
-
I was doing some research for a project. I wanted a number comparable to rubber domes, I couldn't find a number anywhere.
-
I am truly impressed.
Or, as non-typists say,
u r 1 bad mf
Do your fingertips have callouses, or have you worn off your fingerprints?
-
So who here has legitimately worn out an IBM Model M? Ah, right. I'm the guy who did that.
Model M enthusiast here: bowing low!
-
Same for broken springs; they are replaceable with some effort
Question is life before wear out, not how serviceable it is. You can replace microswitches or parts more or less.
-
Let's see - 50M MTBF for a mechanical switch versus 10M MTBF for a rubber dome. We have a real life example of 1,226,400,000 keystrokes for a 101 key keyboard (the IBM Model M). 12M per key. Sounds about right given the varying key frequencies.
What keys specifically wore out? Statistically should look something like this:
THIS is how you do a A+ Science paper. Not just post on a Internet Forum.
Damn T-Ball Generation, expects an award for showing up to the game.
Believe it or not, not those keys. Bear in mind, my typing is atypical, so results not guaranteed. The first keys to go south were actually the numpad, bearing in mind, that just that section probably snuck in another half billion keystrokes or so. (I was only estimating words, and probably underestimating at that.) Matrix failure started at left shift - presumably due to all the programming work done on it, primarily in FORTRAN and SQL. Quelle surprise there, right? I also have a tendency to lean into it. If the backing plate is holding, leaning will wear things out faster. I didn't bother to, but should have counted how many stabilizing rods I replaced. It was more than a few.
Probably the biggest factor by far in killing any Model M is the actual physical typing habits, not the keys pressed or any of that. They're not exactly keyboards you can use kid gloves with with for obvious reasons, but if you have habits like leaning or riding, it can shorten the life significantly. The specific typing habits WRT keys pressed don't really have any significant bearing on it.
I could do the whole science report thing - I still have that keyboard around here somewhere - but I don't have time to disassemble and retest. Now, that said, I've had two '91's that didn't last 3 years before developing numpad problems (from different sources, just to be sure.) And a '89 which just may have 2B+ keystrokes on WASD which chews up caps but keeps working. So there is a tremendous amount of variance year to year and model to model even though there shouldn't be. Those are the ugly ones; the isolated key problems.
That's the other thing about Model M. You're not dealing with a keyboard - you're dealing with a mechanical engineering project. When you bend that backing plate, you actually affect the lifespan of the entire keyboard. When you lean/roll onto the left shift key hard, you're actually damaging mechanical components over time. When you stretch it out over 12 years, microfractures become visible cracks, so on, so forth. Biological contaminants contributing to corruption (you sneezed, don't lie), and so on. That isn't to say that a Model M is not almost literally a battletank - they engineered these things to be bulletproof, after all. But there's only so much that can be done in the hands of the unwashed masses (currently under the symptoms of an allergy attack.) Every M is not created equal, nor is every user created equal.
Rip's pattern, by the by, is exacly where I expect it to be for traditional typing. Specifically, email, writing fiction and non-fiction, etcetera. But very much not the layout for someone who work sin for example, hexadecimal. (A-F,0-9) which means that you use 16 keys common, plus 6 keys modifiers, which means a string is in fact 12 keypresses. Same deal with C; you'll heavily lean on {} [] and <> and ., which you don't see outside of programming. Also a lot of \. System Administrators, you'll see a very different pattern centered around short commands that go long.. ls -l -a -x -v - stacking in spacebar and hypen.
-
Amazing and enlightening. Thank you for sharing this.
My humble padawan comments pale in comparison to your knowledge, but I will say that this converted Model F terminal that I am using now would have made most of those comments about the cracking/warping back plate evaporate. Bolt-modding a Model M helps a lot but it still stresses the plastic barrel plate (that is the right name, isn't it?) as it pulls it to the inside of a curve.
The curved metal plate of the F, in comparison, is closest to the keys, so it takes all the user pressure to protect the components below.
Replacing stabilizing rods surprises me. Most of the grief I have faced comes from problems, not with the rods, but with those little plastic flanges that hold the rods to the plate, or, even more, the tiny little plastic brackets built into the spacebar to hold them. Obviously the spacebar fix is easy - throw the spacebar into the garbage and get a new one!
And I have asked whether it is possible to replace the flanges (is there a name for them?) but nobody has answered. I may try something involving epoxy but do not trust it long-term.
[ATTACH=CONFIG]31917[/ATTACH]
As far as stabilizing bars in general, I am really warming up to the non-bar style with the leg built into the key stems and cylindrical barrel inserts into the board. These have worked fine for me but I have not logged in even a tiny fraction of the time that Rootwyrm has.
Thank you again for sharing your experiences.
-
we should put a paypal fund together and pay a teenager 10 bucks an hour to find out exactly how many presses it takes. Just press 1 key for 8 hours a day, logging presses.
Or we could use a machine.
I think the machine would fail before the keyboard!
-
I have just found this on clickey keyboards (http://clickeykeyboards.com)
...The mechanical key switch that is used in these keyboards is rated at 25,000,000 (25 million) key strokes. We have never seen a keyboard die all of a sudden from excessive use.
Source (http://www.clickeykeyboards.com/model-m-buyers-guide/)
-
I think the machine would fail before the keyboard!
lol, I think so too! Wouldn't that be funny?
-
I have just found this on clickey keyboards (http://clickeykeyboards.com)
Source (http://www.clickeykeyboards.com/model-m-buyers-guide/)
As Ripster pointed out, they're wrong about a lot. Among these things, is that. There are only two failure modes for a Model M: abrupt mechanical and abrupt electrical. Abrupt mechanical is, not surprisingly, a broken spring. Abrupt electrical happens. And happens not infrequently. It's called failed controller, and it does occur. I've had more than a few. If abrupt electrical failure didn't occur for any number of reasons, every device you ever bought would have a lifetime warranty, because it would never break.
And they are wrong about the keys. The wear difference between two piece keys and one piece keys is a reality, though you're talking about needing to go through several sets of keycaps and millions of keystrokes to actually test it. In the real world. I can also tell you that certain sets do wear differently. Enough to declare X is superior to Y? Not even remotely. It's most likely a question of storage and exposure accounting for the difference in wearing. Plastics do degrade.
-
Are you taking IBM keyboards to a cult level or what?
-
Are you taking IBM keyboards to a cult level or what?
haven't we already?
There's some good information in this topic, thanks for all the interesting info, Rootwyrm.
-
haven't we already?
There's some good information in this topic, thanks for all the interesting info, Rootwyrm.
Very welcome!
Also, man enough to admit when I'm wrong. I've got a '91 here that's exhibited a new failure condition! When I say "intermittent fault" the typical expectation is broken bolts. But it's not broken bolts. It's only one key - numpad asterisk - which makes matrix failure unlikely. (It's X7Y14 for the curious.) X7 is the most populated horizontal column and Y14 is the second most populated vertical, so if it was matrix or controller I'd be seeing it on more than one key. So maybe it was gunk on the membrane? Gunk on the membrane doesn't result in intermittent 'no work' along with 'works fine' and 'registers 2-6 times when struck.'
I am completely stumped. But since some jerk stole my nut driver and I haven't found a good replacement yet (but a bunch of ones that DON'T FIT in the narrow channel holes,) the actual fault remains a mystery. Damndest thing I've ever seen on an M, too. It's not just the one key part, it's the occasional multiple registers that's throwing me off. Never seen it before in my life.
-
Very welcome!
Also, man enough to admit when I'm wrong. I've got a '91 here that's exhibited a new failure condition! When I say "intermittent fault" the typical expectation is broken bolts. But it's not broken bolts. It's only one key - numpad asterisk - which makes matrix failure unlikely. (It's X7Y14 for the curious.) X7 is the most populated horizontal column and Y14 is the second most populated vertical, so if it was matrix or controller I'd be seeing it on more than one key. So maybe it was gunk on the membrane? Gunk on the membrane doesn't result in intermittent 'no work' along with 'works fine' and 'registers 2-6 times when struck.'
I am completely stumped. But since some jerk stole my nut driver and I haven't found a good replacement yet (but a bunch of ones that DON'T FIT in the narrow channel holes,) the actual fault remains a mystery. Damndest thing I've ever seen on an M, too. It's not just the one key part, it's the occasional multiple registers that's throwing me off. Never seen it before in my life.
Hmm, it could be slightly conductive gunk in there.