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geekhack Community => Keyboards => Topic started by: ch_123 on Thu, 06 August 2009, 15:23:19

Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: ch_123 on Thu, 06 August 2009, 15:23:19
My bet is that it's louder and bottoms out really quickly.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: ch_123 on Thu, 06 August 2009, 15:33:50
What I meant was that after the switch actuates, it falls away quicker. Though now that I think of it, that may or may not be true. Im definitely expecting it to have a different sound - a double ping. I don't think there's going to be a change in feel or activation force.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: Rajagra on Thu, 06 August 2009, 15:33:52
Quote from: ripster;107594
Speculations??

"You'll have someone's eye out with that!"

I'm guessing the energy has to go somewhere, so there will still be sound, but very different to before.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: timw4mail on Thu, 06 August 2009, 16:19:13
It might actually feel more linear now. Unless I'm mistaken about which part of the key you cut out.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: talis on Thu, 06 August 2009, 16:27:52
Since the spring makes no contact except at the top and bottom right up to the point that it buckles I would be surprised if either the force to activation or the key feel changed at all.  I doubt it would feel much different after the activation point either.  You're still compressing the same spring in the same way after all.

I wouldn't be surprised if the key sounded roughly the same as always.  If that's the case, the sound must come entirely from the spring banging against itself at the point it buckles, which isn't all that hard to believe.  Alternatively it may be a bit quieter if most of the sound comes from the ridge in the key cap.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: ch_123 on Thu, 06 August 2009, 16:47:09
*smug look*

Pretty much what I expected. A buckling spring usually makes a dignified snap on the downpress, and then the distinctive ping sound when you release the key. My guess as to why it doesn't ping on the way down is because the spring hits the barrel, and this absorbs some of the force and possibly stops it vibrating. Listening to the recordings, it sounds quite pingy both up and down. So, that's pretty much the last BS sound puzzle solved. Thanks Ripster!

Although you didn't say it explicity, I'd assume that it felt pretty much the same?
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: wellington1869 on Thu, 06 August 2009, 16:53:00
they all sound the same. I was going to guess C :) cuz this came up once before and tho I forget the train of thought, it was decided that the spring-on-barrel wasnt the main source of the click.

but how to explain it? where the hell is the click coming from? from a combination of all these things? (hammer, barrel, bottoming/topping of stem, etc)?
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: ch_123 on Thu, 06 August 2009, 16:55:19
Yeah, it seemed unlikely that the feel would change, after all, the spring doesn't hit or go beyond the barrel until after it actuates.

Quote
The sound I think is a combo of spring snap against key and well, and the foot snap adding a certain amount as well - as much as 50/50.

I'm still sticking to my theory that the barrel actually quietens the the thing by taking the impact of the spring. What do you mean by foot snap?

Quote
but how to explain it? where the hell is the click coming from? from a combination of all these things? (hammer, barrel, bottoming/topping of stem, etc)?

Again, I post my 'thesis' on BS sounds for those who haven't read it. (here (http://geekhack.org/showpost.php?p=102822&postcount=1)) And once again, it's not the hammer folks, it's the springs :)

Ripster, there's one more thing you could try, although the setup would be harder with the shorter hammers on the Model M - try and recreate my hammer noise experiment (ie. rest the pivoting part of the hammer on a firm surface but make sure the hammer doesn't actually hit anything when it snaps down)
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: wellington1869 on Thu, 06 August 2009, 17:07:47
quoting from ch_123's thesis:
Quote

It's also worth noting that when I pressed the key while the assembly was resting on the desk and the book, it sounded pretty much identical to how it would normally sound inside the keyboard. That's not to say that the surface has no impact on sound and feel, just that it's going to be pretty much constant as long as it's resting on a firm surface


in other words, I think, the spring makes the click no matter whether or not there is any plastic near, around, above, below, or beside it.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: talis on Thu, 06 August 2009, 17:08:44
Quote from: ch_123;107662


Ripster, there's one more thing you could try, although the setup would be harder with the shorter hammers on the Model M - try and recreate my hammer noise experiment (ie. rest the pivoting part of the hammer on a firm surface but make sure the hammer doesn't actually hit anything when it snaps down)


I did that exact experiment here (http://geekhack.org/showpost.php?p=101947&postcount=31) and came up with the same results.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: ch_123 on Thu, 06 August 2009, 17:10:52
Quote
ch_123's thesis


Please tell me the irony/self-deprecation wasn't lost on you? =P

Quote
in other words, I think, the spring makes the click no matter whether or not there is any plastic near, around, above, below, or beside it.


Ah, but there's two sounds when you press a buckling spring, the snap when you press it down, and the ping when it comes back up. That ping is going to be pretty much consistent, but I think the sound it makes on the way down would be affected by it hitting, or not hitting something as it buckles out.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: ch_123 on Thu, 06 August 2009, 17:12:36
Quote from: talis;107667
I did that exact experiment here (http://geekhack.org/showpost.php?p=101947&postcount=31) and came up with the same results.


Ah very good, so it's consistent across the two main variants of buckling spring. I'd agree with your remark on resonance, there's definitely some echo going on when it's assembled inside the keyboard, but like you, I found it made the same type of noise when the hammer didnt hit anything.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: wellington1869 on Thu, 06 August 2009, 17:13:07
quoting from Talis' laboratory:  

Quote

I held the hammer stationary while I actuated the key with my other hand. The click was almost exactly the same as when the board was together. When I put the board down on my desk, and held the hammer in place with a screwdriver it sounded exactly like it does when fully assembled.

So my conclusions are :

1) The sound comes almost entirely from the spring, key stem, and key cap


probably dont even need the keystem and keycap for the click to occur if its just the spring. So long as the spring is held in place firmly, it'll click when pressed, apparently.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: wellington1869 on Thu, 06 August 2009, 17:15:11
Quote from: ch_123;107668
Please tell me the irony/self-deprecation wasn't lost on you? =P

hey, this is serious work we're doing! ;-D

Quote

 I think the sound it makes on the way down would be affected by it hitting, or not hitting something as it buckles out.


"affected" yes, but not eliminated, right? In other words, even without plastic, it clicks when pressed down, maybe just not as loudly, right?
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: talis on Thu, 06 August 2009, 17:15:30
Quote from: ch_123;107669
Ah very good, so it's consistent across the two main variants of buckling spring. I'd agree with your remark on resonance, there's definitely some echo going on when it's assembled inside the keyboard, but like you, I found it made the same type of noise when the hammer didnt hit anything.


As a corollary, if you look down a narrow piece of board, you see the hammer only travels 1mm at most from its up to fully actuated position.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: ch_123 on Thu, 06 August 2009, 17:19:10
Quote from: wellington1869;107672
hey, this is serious work we're doing! ;-D



"affected" yes, but not eliminated, right? In other words, even without plastic, it clicks when pressed down, maybe just not as loudly, right?

It would be yes. But I'm saying that it would make a slightly different sound if there was nothing in the way of the spring when it buckles - a 'ping'-'ping' as opposed to the 'snap'-'ping' you get on an unmodified BS keyboard. (If I sound confusing, press a key on a BS board down slowly, wait a second, then release, you'll see what I mean about the 'snap'-'ping')
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: ch_123 on Thu, 06 August 2009, 18:22:12
Quote from: ripster;107678
No.  It makes some sproingy noises with no plastic around it but no click if I just buckle a spring holding a spring/hammer in my hand.


No suprise. It needs to be tensed between two fixed points and press down perfectly straight, there's no way somone can do that with their fingers.

Have you tried seperating a single barrel from the rest and testing whether or not the hammer does anything? I'm still sticking to the theory that the hammer has little to no effect on the sound of it.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: JBert on Thu, 06 August 2009, 18:49:34
So it must be the springs... Couldn't we apply some rubber-like material to dampen the movement of the separate coils in the spring while still allowing it to be pressed?

I'm thinking about that plasti-dip stuff now, but I haven't got that nor spare springs. Also, I wonder how it could be applied to the spring and if so, where exactly?

My current thought would be to place a spring them on some non-sticky surface like teflon, spread a .5mm thick line of that plasti-dip, put the spring in it and left to dry. Rotate the spring 180 degrees and repeat.

If you'd then have two of them, you could place them in 2 different rotations: one with the rubber strips aligned with the buckling motion and one perpendicular to it.

Anyway, just thinking in text here.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: ch_123 on Thu, 06 August 2009, 19:00:38
Quote from: ripster;107708
Once again.  Take apart a Bic pen.  Buckle spring.  No click.  None.


Take a hammer, smack it against the PCB, no click, none.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: JBert on Thu, 06 August 2009, 19:01:00
Quote from: ripster;107708
Once again.  Take apart a Bic pen.  Buckle spring.  No click.  None.
Maybe no clicks, but "ping" it will. Heck, ever seen one of those fake mikes kids play with which keep on reverbing shortly after you stopped singing in them? They have one big coil spring inside.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: wellington1869 on Thu, 06 August 2009, 19:04:33
Count me among those who say spring clicks by itself, tho barrel and hammer may "augment" that sound.

Quote

And it doesn't make any sense that springs alone would cause clicks - that's easy to test by taking apart a Bic pen.

but as ch123 is saying, "It needs to be tensed between two fixed points and press down perfectly straight, there's no way somone can do that with their fingers".

So i'm going to take a third thesis (call it the "three-part-click" theory (which is also thus the "spring-clicks-too" theory)) here and say the hammer and the barrel augment a built-in-spring-alone "light click". What you're calling a sproing, I would say if you could hold the spring firmly, it would become more like a light click than a sproing. See below for some more speculative evidence for this.

Quote

Anyway, the bad news is there's no easy way to silence a Buckling Spring.

Also, lightening it will be tough as well. I assume IBM did all these tests earlier.


grease does *wonders* to reduce click and even silence it -- and if you look at how the grease works (http://geekhack.org/showpost.php?p=72685&postcount=4), it affects teh spring directly (it does nothing much to the barrel or hammer), again supporting the spring-is-the-main-click theory.
(I have audio files in that thread, of silenced and non-silenced clicks using grease). I also put audio files in my 'noisykeyboard' thread. (http://geekhack.org/showpost.php?p=72675&postcount=19)

And when I put an rubber ink sac over the spring (http://geekhack.org/showpost.php?p=75895&postcount=10) (rather than grease), the click vanished altogether, while the switch worked fine. In that case I dont even think the spring was buckling, tho the hammer was triggering fine just from the spring 'bending'. No click, absolute silence.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: maxlugar on Thu, 06 August 2009, 19:06:04
Quote from: ripster;107678
No.  It makes some sproingy noises with no plastic around it but no click if I just buckle a spring holding a spring/hammer in my hand.


Anyway, the bad news is there's no easy way to silence a Buckling Spring.

Also, lightening it will be tough as well.  I assume IBM did all these tests earlier.


Is the goal to completely silence or just reduce the sound made by the buckling spring?  I personally enjoy buckling springs in part for the audible feedback.

Also, I'm curious what impact some of the things being proposed to silence the springs would have on the tactile feel of the key presses.  I am fond of Model Ms but prefer 84-key PC AT keyboards over Model Ms for their sharp, precise "crispness".

I wonder how important these attributes are to others and how much they would be willing to trade off for quieter key presses.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: wellington1869 on Thu, 06 August 2009, 19:15:55
wow, consensus! does that mean the mystery is solved? all three components (spring, hammer, barrel) probably contribute some amount to produce the final click?

I mean, if we have consensus this should be a sticky thread. Or atleast linked in the ibm wiki. :)

the forum has been wrestling with this mystery without consensus for a loooong time.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: wellington1869 on Thu, 06 August 2009, 19:22:59
Quote from: ripster;107718
Not until my depression over not creating a silent Buckling Spring ebbs...  I saw myself hustling to Washington DC to renew that patent!


true, that would have been quite an invention. (saturating with grease makes it silent but also loses tactility, unfortunately. Which makes sense because in this case the same source (the spring) produces both the sound and the tactility in one shot. Mess with one and you cant help but mess with the other).

A tactile-but-silent buckling spring would have been something to see.

Of course there still might be a way to do it, if we've advanced our understanding of the buckling spring mystery.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: maxlugar on Thu, 06 August 2009, 19:25:30
Quote from: wellington1869;107717
wow, consensus! does that mean the mystery is solved? all three components (spring, hammer, barrel) probably contribute some amount to produce the final click?
QUOTE]

No one has been yet been able to adequately explain the reason why the Model F and PC AT key presses are so different from Model M key presses.

I've read many theories but I don't believe I've seen consensus on the reason for the differences.  Both use buckling springs but from what I've read, the difference in sound and feel can't be explained by capacitive contact vs. membrane.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: ch_123 on Thu, 06 August 2009, 19:26:58
Well, it would make some noise, but not an awful lot. It's a small piece of plastic hitting against some plastic (albeit firmly mounted on a steel plate) I really don't see how that's going to make a very loud noise.

Quote
I did the same test you did by just sticking the edge of steel ruler on the edge of the hammer while in the well and leaving the foot touching just air.


When you say foot, do you mean the front part of the hammer that actually moves when you buckle the spring?

Quote
No one has been yet been able to adequately explain the reason why the Model F and PC AT key presses are so different from Model M key presses.

I've read many theories but I don't believe I've seen consensus on the reason for the differences. Both use buckling springs but from what I've read, the difference in sound and feel can't be explained by capacitive contact vs. membrane.

Longer springs on the F. By means of converse proof, by shortening the spring, Ripster made one of the keys on his keyboard stiffer. My guess is that because there is more spring to buckle, and more spring to buckle back, this leads to the lower actuation point, and greater bounceback.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: timw4mail on Thu, 06 August 2009, 19:30:42
Quote from: maxlugar;107722


No one has been yet been able to adequately explain the reason why the Model F and PC AT key presses are so different from Model M key presses.

I've read many theories but I don't believe I've seen consensus on the reason for the differences.  Both use buckling springs but from what I've read, the difference in sound and feel can't be explained by capacitive contact vs. membrane.


Supposedly it's the springs, but I'm not completely sure that's the only reason. The springs are longer, and slightly lower force than the Model M. With the Model F, you could take a keycap off, slide the spring forward, and you've activated that switch. With the Model M, you actually have to hit the membrane hard enough for it to register, requiring more force than on the Model F. Or at least, that's how I understand it.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: wellington1869 on Thu, 06 August 2009, 19:33:47
Quote from: ripster;107724

Makes me wonder who the lead engineer on this was?  Did he lock himself in a room with a bucket of springs for days?


Seriously. Or was this invented by some happy accident? Its an almost impossible system of "controlled instability" and very subtle tuning. Hard to imagine it being designed from the ground up.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: ch_123 on Thu, 06 August 2009, 19:34:04
Quote from: timw4mail;107725
Supposedly it's the springs, but I'm not completely sure that's the only reason.

The problem is, there's nothing else that could explain it. Anything else would be so obscure that it couldn't possibly have a serious effect. I think it makes sense that the length of the spring would explain the differences between the two.

Quote
Seriously. Or was this invented by some happy accident? Its an almost impossible system of "controlled instability" and very subtle tuning. Hard to imagine it being designed from the ground up.

Yeah, there must be about 10,000 easier ways to make a tactile switch than using buckling springs... So, who wants to track down Richard Hunter Harris and ask him what he was smoking at the time? =P
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: wellington1869 on Thu, 06 August 2009, 19:35:12
btw ripster kudos on some truly brilliant hacksaw and camera work.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: timw4mail on Thu, 06 August 2009, 19:35:58
Quote from: ch_123;107728
The problem is, there's nothing else that could explain it. Anything else would be so obscure that it couldn't possibly have a serious effect. I think it makes sense that the length of the spring would explain the differences between the two.


Well, I'd say it doesn't really explain the "crispness" very well. I'd say that has to have SOMETHING to do with the foot.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: timw4mail on Thu, 06 August 2009, 19:42:18
Quote from: ripster;107733
I shouldn't say something about a keyboard I don't own but I do agree.  The patent makes a fairly big deal about leverage.  That big foot must have some serious leverage and really slap that PCB.


Well, the funny thing about the foot is that it doesn't need to do much more than brush the PCB. I can take of a keycap, push the spring forward, and the keypress registers. I would try to compare with my Model M, but I don't have it with me at the moment.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: ch_123 on Thu, 06 August 2009, 19:44:41
Go read my big post thats linked on page 1...

It's funny. People around here seem to have this attitude towards the hammer that if they believe in the hammer's importance enough that it will come true, and are prepared to ignore at least two peope who've shown that it really doesn't do all that much.

Think about this, your finger is acting down in a straight line on a keycap which in turn pushes down on a spring which is attached to a pivoting point that is fixed in place. How does a piece of plastic that hangs off the side make what you feel any more crisp? By the time the hammer hits the membrane or PCB, you don't even have a 'direct connection' with the pivot or hammer any more because the spring has buckled out to the side.

Quote
That big foot must have some serious leverage and really slap that PCB.

It does. But that doesn't mean that it makes a big noise. It's a small piece of plastic hitting off another piece of plastic. The noise is pretty much lost in the sound the rest of the mechanism makes.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: timw4mail on Thu, 06 August 2009, 19:50:56
Quote from: ch_123;107738
Go read my big post...

It's funny. People around here seem to have this attitude towards the hammer that if they believe in the hammer's importance enough that it will come true, and are prepared to ignore at least two peope who've shown that it really doesn't do all that much.

Think about this, your finger is acting down in a straight line on a keycap which in turn pushes down on a spring which is attached to a pivoting point that is fixed in place. How does a piece of plastic that hangs off the side make what you feel any more crisp?


Well, do you have a better idea of what makes it feel more crisp? I realize that it probably doesn't affect the feel that much, but the Model M feels mushier, and it hits a membrane, versus the Model F, which hits the PCB.  I agree that it doesn't make too much sense, considering the amound of 'levers' in between the keycap and the foot, but I can't really think of a better explanation.

The springs definitely play a big role in the difference between the two boards, but the only other thing I can think of that would cause so much difference is the force of the spring hitting the buckle zone on the keycap. Considering the keycaps are virtually the same on the Model F and the Model M, I don't know how likely this is either.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: ch_123 on Thu, 06 August 2009, 19:58:33
To be honest, I'm not an expert in the physics of springs, but it would seem to me that if there is more spring, there's going to be more of a sudden drop when it buckles, and this is why you feel a much sharper change in force when the longer spring buckles. For the reasons I gave above, I really really doubt that you feel what the hammer hits.

Quote
I realize that it probably doesn't affect the feel that much, but the Model M feels mushier, and it hits a membrane, versus the Model F, which hits the PCB.

Again, I refer you to my big post on this stuff. I tried out a Model F buckling spring assembly on a wooden desk, a thick book, the PCB and some other firm surfaces and the feeling didn't change. As long as the surface is firm, it works. You have to remember of course that the membrane is relatively thin and is mounted on a steel plate, it's not really a case of hard PCB versus flimsy membrane, they are both tough surfaces for all intents and purposes.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: timw4mail on Thu, 06 August 2009, 19:59:23
Quote from: ripster;107742
Show Image
(http://itsourblog.typepad.com/photos/uncategorized/2008/08/26/feet2.jpg)


Actually, I do feel a difference even on my wooden model when I push the key and hold the foot.  Never underestimate the subtlety of the Buckling Spring!  Plus, I assume there's something psychologically satisfying in hearing a foot slap.  Might equate to crispness.


Ripster, you really should get a Model F, so you can actually make sense of the difference in feel.

Besides, who doesn't like a 7 inch long spacebar?
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: maxlugar on Thu, 06 August 2009, 20:00:59
Quote from: ch_123;107723

 
Longer springs on the F. By means of converse proof, by shortening the spring, Ripster made one of the keys on his keyboard stiffer. My guess is that because there is more spring to buckle, and more spring to buckle back, this leads to the lower actuation point, and greater bounceback.


Besides spring length, has anyone compared other attributes of the Model F springs vs. the Model M springs. For example, are they made from the same kind of steel, the number of coils per inch, the gauge (thickness) of the wire, etc.

I removed all the keycaps from one of my PC AT keyboards for cleaning and while the barrels and springs were exposed, the F7 spring got snagged on the towel I was using and was subsequently pulled hard enough to deform the spring.  I was not able to "recompress" the spring back into its orginal tightly coiled form.

I sent the keyboard to Unicomp for repair.  They replaced the spring with a spring I presume they use in their current boards.  The repaired F7 key once again buckles, but both the sound and feel are different from the all the other keys.  The click is not as pronounced and it is a tad bit softer (quieter). It almost, but not exactly, like a Model M key!

This would support the theory that the spring is the most important, but not the only component that differentiates the Model F from the Model M.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: ch_123 on Thu, 06 August 2009, 20:04:27
That's weird... If the spring on the Model F is longer than that of a Model M, wouldn't a Model M spring be too short to fit into a Model F?
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: timw4mail on Thu, 06 August 2009, 20:08:32
Quote from: ch_123;107753
That's weird... If the spring on the Model F is longer than that of a Model M, wouldn't a Model M spring be too short to fit into a Model F?


Considering how little the foot actually has to touch the PCB, the shorter spring probably isn't that big of a deal. Or it's a same length spring, made with a different alloy.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: ch_123 on Thu, 06 August 2009, 20:12:16
No, I've seen a pic of the two side by side, the F is definitely longer. But I'm now thinking that material could be an issue here. Oh wait, found the picture, I think I found what the missing reason is -

(http://s727.photobucket.com/albums/ww280/switch-kitten/ibm%20pc%20xt/DSCN6103.jpg)

Definitely more coils per inch on the F...

EDIT: Ripster beat me to it it seems. The A01 is reputedly slightly stiffer than a Model M. So I'd say that if you got a Model M spring, it would be midway in terms of coil density, and possibly length.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: maxlugar on Thu, 06 August 2009, 20:13:33
Quote from: ch_123;107753
That's weird... If the spring on the Model F is longer than that of a Model M, wouldn't a Model M spring be too short to fit into a Model F?


I don't know for sure, but my guess is that the springs are fabricated in long rolls and cut to the appropriate length as part of the manufacturing assembly process.

When Unicomp replaced the F7 spring, perhaps they just cut a new spring from a longer roll.  I don't see how it would be possible to replace the old spring with a shorter spring and still enable the buckling spring mechanism to function properly.

Either they cut a new spring for me or they just happened to have a spare spring with the appropriate length in parts inventory.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: timw4mail on Thu, 06 August 2009, 20:13:35
Quote from: maxlugar;107751

I sent the keyboard to Unicomp for repair.  They replaced the spring with a spring I presume they use in their current boards.  The repaired F7 key once again buckles, but both the sound and feel are different from the all the other keys.  The click is not as pronounced and it is a tad bit softer (quieter). It almost, but not exactly, like a Model M key!


I bet they just loved working on a Model F :suspicious:

I'm kind of suprised that they did repair it. From what I understand, the Model F is significantly harder to work with than the Model M, at least from a repair standpoint.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: ch_123 on Thu, 06 August 2009, 20:16:07
I'd say it's probably easier. No membrane or plastic rivets to kill.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: maxlugar on Thu, 06 August 2009, 20:28:35
Quote from: timw4mail;107762
I bet they just loved working on a Model F :suspicious:

I'm kind of suprised that they did repair it. From what I understand, the Model F is significantly harder to work with than the Model M, at least from a repair standpoint.


Unicomp says they will repair any IBM keyboard for a flat fee of something like $30 or $35, I don't remember exactly.

The amount that was actually charged to my credit card for the repair was $7 less than the "flat fee" I was originally quoted.  An unexpected display of high integrity from those Unicomp guys.  I gotta tell ya, I hope they remain a viable operation.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: lal on Fri, 07 August 2009, 11:04:01
Quote from: ripster;107678

Anyway, the bad news is there's no easy way to silence a Buckling Spring.


Actually that is *good* news!
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: ch_123 on Fri, 07 August 2009, 11:14:56
It makes a little bit of a difference, but it still doesn't explain why the sound remains mainly constant (and the click sound entirely unchanged) when tested on different surfaces. It's definitely not one of the main contributing factors to the noise, only adds a little bit on the side.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: wellington1869 on Fri, 07 August 2009, 11:35:27
Quote from: lal;107930
Actually that is *good* news!


lol. I wouldnt want my endurapro completely silent, though I'd be interested to know what such a 'silent' bs switch would feel like.

I do like my endurapro 'sound-dampened' though.  Grease really does work very well. I havent really needed to refresh the grease either. (I did that once but in retrospect I dont thnk it was really necessary). Its been 6 months now and the sound level is still where I want it to be.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: wellington1869 on Fri, 07 August 2009, 12:43:51
i cant believe it, you're questioning your own ripOmeter's accuracy on this? It was the ripOmeter that convinced me i wasnt imagining the unicomp's lightness!
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: timw4mail on Fri, 07 August 2009, 14:30:16
Quote from: ripster;107978
Well, they do feel different to me but when you try to measure a buckling spring they don't cooperate.  I remember Huha posting some fancy graph and the points had quite a bit of variance.

The other factor is I think tightening up the keyboard with Bolts/Nuts probably makes the springs a tad stiffer.  Just too many things going on here.  Bizzarro.

It's not like Physics are simple.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: wellington1869 on Fri, 07 August 2009, 14:42:28
adds to the mystique of the bs switch. Its kind of nice that such perfection is the result of such fine balance of chaotic and unstable forces. Its like its all held together with a wizard spell. ;)
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: timw4mail on Fri, 07 August 2009, 14:47:32
Quote from: wellington1869;107997
adds to the mystique of the bs switch. Its kind of nice that such perfection is the result of such fine balance of chaotic and unstable forces. Its like its all held together with a wizard spell. ;)

Or maybe it's just really difficult to have consistent springs, plastics, and keycaps?
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: CX23882 on Fri, 07 August 2009, 15:40:29
Quote from: maxlugar;107767
Unicomp says they will repair any IBM keyboard for a flat fee of something like $30 or $35, I don't remember exactly.


Even this?
http://geekhack.org/showpost.php?p=106113&postcount=28
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: rdjack21 on Fri, 07 August 2009, 16:01:43
Quote from: CX23882;108011
Even this?
http://geekhack.org/showpost.php?p=106113&postcount=28

LOL I guess he could put all the parts in a box and send it to them.

UNICOMP Receiving department:
What the @#% is this. Does this ripster person really think we are going to fix this! Oh well you know the policy we fix them all send it over to the repair techs.

UNICOMP Repair techs:
What the #$%# is this box of crap. Oh I see this ripster person at least left the label so we know what it should be. What the #$#% is the glob of plastic for?  Heck if they have the Balls to send this in just send them a new one and be done with it. Hey whats this note say http://geekhack.org/showthread.php?p=108014 (tech gets on computer and enters the url). What the heck are these guys doing Oh my god look what he did to our board. Buy hey kinda of cool but hey we know all this stuff already. They don't deserve a new board where is that reject board we had laying around yesterday send him that one.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: timw4mail on Fri, 07 August 2009, 16:33:15
Quote from: rdjack21;108014
LOL I guess he could put all the parts in a box and send it to them.

UNICOMP Receiving department:
What the @#% is this. Does this ripster person really think we are going to fix this! Oh well you know the policy we fix them all send it over to the repair techs.

UNICOMP Repair techs:
What the #$%# is this box of crap. Oh I see this ripster person at least left the label so we know what it should be. What the #$#% is the glob of plastic for?  Heck if they have the Balls to send this in just send them a new one and be done with it. Hey whats this note say http://geekhack.org/showthread.php?p=108014 (tech gets on computer and enters the url). What the heck are these guys doing Oh my god look what he did to our board. Buy hey kinda of cool but hey we know all this stuff already. They don't deserve a new board where is that reject board we had laying around yesterday send him that one.


Repair technetions must have some amusing days.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: lowpoly on Fri, 07 August 2009, 16:42:41
Quote from: wellington1869;107717
wow, consensus! does that mean the mystery is solved? all three components (spring, hammer, barrel) probably contribute some amount to produce the final click?

I mean, if we have consensus this should be a sticky thread. Or atleast linked in the ibm wiki. :)

the forum has been wrestling with this mystery without consensus for a loooong time.

Having the separate A01 switches to play with, I still think it's the hammer, not the spring. Why should the spring click on its own? Ping on the way back maybe, that sounds like a fast vibration. But click? No way. Something hitting something else OTOH, like the hammer... That's why the open key is louder.

Have to make a video, maybe tomorrow.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: wellington1869 on Fri, 07 August 2009, 17:06:32
Quote from: ripster;108032


Has all the makings of a grand Doctoral Thesis.


seriously.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: ch_123 on Fri, 07 August 2009, 17:08:14
Christ, if this 'Cult of the Hammer' continues, I'm going to have to open up my Model F again... Knew I should have made videos the last time 8-)
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: wellington1869 on Fri, 07 August 2009, 17:22:43
Quote from: ripster;108037

For yuks I'm going to PlastiDip a spring/hammer and see what happens


that would be awesome.
tho my guess is it wont buckle at all. no buckle, no fun.

or, paint plastidip on the barrel wall?
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: timw4mail on Fri, 07 August 2009, 18:44:05
Quote from: ch_123;108035
Christ, if this 'Cult of the Hammer' continues, I'm going to have to open up my Model F again... Knew I should have made videos the last time 8-)

You make it sound like that was a chore :lol:
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: ch_123 on Fri, 07 August 2009, 19:05:20
Believe me, it loses it's charm after you've done it for the third or fourth time.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: JBert on Sat, 08 August 2009, 05:57:42
Quote from: ripster;108037
For yuks I'm going to PlastiDip a spring/hammer and see what happens
If you do go ahead, try to vary the amount of the stuff.
Maybe it is already enough to apply two thin strips to dampen the spring, whereas a full coat could make it stop buckling.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: lowpoly on Sat, 08 August 2009, 11:33:33
5576-A01 Switch Sound (http://www.youtube.com/watch?v=Bwp6FOul2Z0)

How do I embed a youtube video here?

Oh, and the lens cover is sliding on the desk. And the fan added some wind noise. :frown: I hope you don't mind.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: timw4mail on Sat, 08 August 2009, 11:40:03
Quote from: lowpoly;108196
5576-A01 Switch Sound (http://www.youtube.com/watch?v=Bwp6FOul2Z0)

How do I embed a youtube video here?

Oh, and the lens cover is sliding on the desk. And the fan added some wind noise. :frown: I hope you don't mind.

Buckling spring switches? Where in the world do you get those?
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: wellington1869 on Sat, 08 August 2009, 11:51:59
Quote from: ripster;108198
The Cult of The Hammer strikes again!  Those are the IBM Japanese switches - they come individually.

Nice video.  Boy that is one pingy keyboard though.  It sounds like the spring sproing resonates with the metal plate.

I'll post PlastiDip results in a sec after taking some pics.


in lowpo's video, its hard to say if its quieter because "hammer isnt hitting anything" or if its quieter because when held in the air between fingers there's no resonance.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: wellington1869 on Sat, 08 August 2009, 12:01:15
Quote from: ripster;108208
I think it's time to grab a hammer and start banging heads.

So, you and CH are arguing the hammer makes no sound??


well, i'm arguing that all three contribute (so i'm arguing that hammer sound would be small, not the "main" sound). At this point I'm not sure that there is a "main" sound.  Or, if there is, I'd argue its the "spring itself" that is the "loudest contributor" of sound.

But I can accept that hammer and barrel wall "contribute" some (small?) amount.

So I guess I'm saying the click is more of an "orchestra".  It has three components to it, but is perceived by us as a single click.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: wellington1869 on Sat, 08 August 2009, 12:01:56
I suppose another way to solve this would be to remove the hammer altogether on a switch, reinsert the switch into the board, and press it?
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: wellington1869 on Sat, 08 August 2009, 12:06:43
btw I say "spring itself is loudest" not because I know how the spring works (a perennial mystery) but rather by deduction, having eliminated the other sources, there's nothing else left.

anyway, so i'm willing to cover my butt and say all three contribute and the result is an orchestra and not one main single click.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: timw4mail on Sat, 08 August 2009, 12:08:19
So, that's like how your three posts were about the same point?
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: wellington1869 on Sat, 08 August 2009, 12:10:22
Quote from: timw4mail;108217
So, that's like how your three posts were about the same point?


:) exactly. So now if all three notions had occured in the same moment, then it would be like the click, where all three sounds happen at the same time. :-D

hmmm, this is kind of a holy trinity theory, 3-aspects-in-1, wouldnt you say, tim? :-D
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: wellington1869 on Sat, 08 August 2009, 12:35:41
Quote

After following the "Plastidip your Keys thread" I remembered I had an unopened can of the stuff I was going to use for Birth Control

sheer genius! :-)  A little "dip" before the fun starts and you're all set :-)

Quote

But the can wasn't long enough.

ahahahahahahaha

Quote

Unfortunately, it doesn't buckle like Welly anticipated

well, any buckling spring will tell you, humping the keyboard is a lot more fun without the sheath.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: o2dazone on Sat, 08 August 2009, 12:37:45
That poor Boscom
is there anything it hasnt gone through?
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: ch_123 on Sat, 08 August 2009, 12:51:58
Quote from: ripster;108208
So, you and CH are arguing the hammer makes no sound??

Saying that it makes no sound is slightly misleading. It may make some, but it's largely irrelevant and doesn't change the overall type of sound that the BS mechanism makes.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: lowpoly on Sat, 08 August 2009, 12:53:11
Quote from: wellington1869;108205
in lowpo's video, its hard to say if its quieter because "hammer isnt hitting anything" or if its quieter because when held in the air between fingers there's no resonance.


There are one or two clicks in the video where I let the hammer click freely against its end of movement point. That's also considerably louder than when the hammer is dampened by the finger.

But, having done some more tests, I think my hammer theory doesn't hold. Main reason: the click on the way up is a lot louder with the switch in the board than with the switch alone. And if I apply dampening then the ratio between the up and down sound is always the same: in the air (quiet), on the desk (not as quiet) and in the board (loud).

I'm with the combined sound folks now, I guess. Still, the hammer can provide a lot of noise depending on the situation (density of rubber mat, membrane thickness, travel).

The board adds A LOT of resonance, at least with the A01. There's probably little you can do about this.

Ripster, maybe you can remove the sloped part in one of your stems on your test setup?
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: wellington1869 on Sat, 08 August 2009, 13:03:00
Quote

my real interest is in getting the key force down

mine too.  Sound level can be handled pretty well with silicon grease anyway.

Re: resistance level, I still think there should be an off-the-shelf spring replacement out there. I nominate the boscom for further experimentation there (since I have neither the tools nor the spare boards!).

btw, dry silicon spray on the stem (to my mind anyway) further reduced resistance by a few grams at least. I dont have any data to back this up, but it sure felt that way to my fingers.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: lowpoly on Sat, 08 August 2009, 13:16:28
Quote from: ripster;108244
I did. That whole sloped thing was removed - first key in sound sample.


But wasn't that the loudest one? I give up here.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: ch_123 on Sat, 08 August 2009, 13:18:03
Quote from: ripster;108244
I think someone needs to play around with a Model F now.  Would a Bigfoot Model F hammer fit in a Model M? - lots of room in the black plastic holders.


The idea that someone would do what you did to that Boscom to a Model F is somewhat horrifying. Can it be at least be done to one of those Model Cs that nobody loves? =P
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: wellington1869 on Sat, 08 August 2009, 13:27:34
Quote from: ch_123;108250
The idea that someone would do what you did to that Boscom to a Model F is somewhat horrifying.


i agree. I'd even wince if someone did it to an M unless the M was not functional or something.  Its a bit like killing baby seals, isnt it?

I think someone would have to have one of the 'fringe' bs boards to have the heart to do it. Or a dead one.

I'd experiment with off-the-shelf springs but I'd have to first acquire a "lab rat" bs board. And a band saw. :)
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: wellington1869 on Sat, 08 August 2009, 13:30:24
Quote

Playing with springs is just a variation of the greased method - messes up the key feel.


btw, just for the record, putting a little bit of grease on the springs doesnt mess noticeably with key feel, and does reduce volume quite a bit.  The key feel is only lost if you absolutely saturate the spring (which results in mushy and absolutely quiet keys, which are no fun at all - you may as well buy a $10 dell rubber dome at that point).

but you can modulate both sound and feel with the amount of grease you apply. Apply just a little bit and the results are quite good.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: ch_123 on Sat, 08 August 2009, 13:33:05
I'd recommend these (http://cgi.ebay.com/IBM-5640987-3178-C2-0-Keyboard-ASM_W0QQitemZ200256086957QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item2ea03163ad&_trksid=p3286.c0.m14&_trkparms=65%3A1|66%3A2|39%3A1|293%3A1|294%3A50) as a suitable sacrifice. Probably as cheap as you're going to find any Model F style board these days. You could probably get it for like $20-25 with an offer, they've been around for a while and they have made no sale.

Here's one that Sandy dissected link (http://sandy55.fc2web.com/keyboard/model_m_trivia.html#5640991)
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: timw4mail on Sat, 08 August 2009, 14:35:02
Quote from: ch_123;108259
I'd recommend these (http://cgi.ebay.com/IBM-5640987-3178-C2-0-Keyboard-ASM_W0QQitemZ200256086957QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item2ea03163ad&_trksid=p3286.c0.m14&_trkparms=65%3A1%7C66%3A2%7C39%3A1%7C293%3A1%7C294%3A50) as a suitable sacrifice. Probably as cheap as you're going to find any Model F style board these days. You could probably get it for like $20-25 with an offer, they've been around for a while and they have made no sale.

Here's one that Sandy dissected link[/URL. (http://sandy55.fc2web.com/keyboard/model_m_trivia.html#5640991)

Sounds good to me. We need the few AT Model F's in existence for typing.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: ch_123 on Sat, 08 August 2009, 15:19:30
I bet you anything that it's going to be too small to make the contacts work.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: JBert on Sun, 11 October 2009, 16:22:31
Quote from: ripster;108225

I dipped a spring in [PlastiDip].  Note on the hammer you can see the number 253.  I thought it may be a datecode until I saw one labeled K1.  Another mystery to file along with the PLT number.
Show Image
(http://geekhack.org/attachment.php?attachmentid=3655&stc=1&d=1249751928)


My springy has been - uh - sheathed.  The Catholic Church does not approve of this mod BTW.  Unfortunately, it doesn't buckle like Welly anticipated.
I'm wondering - would it keep functioning if you only coated 3mm of spring, just above the point where the spring and the hammer meet as described in the AT&T "silenced buckling spring" patent? It might be an easier alternative compared to inserting urethane foam cylinders into each spring.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: msiegel on Sun, 11 October 2009, 16:29:09
that's a very interesting idea :D

also, i suspect the small numbers on injection molded parts are used to track down manufacturing defects.

e.g., maybe 50 parts are molded in one shot, and the one in the top left corner is numbered A1... so if a bunch of A1s test bad, you know the top left corner of the mold has a problem.
Title: Buckling Spring Mystery - Not the Click AGAIN!
Post by: wellington1869 on Sun, 11 October 2009, 16:35:05
ya, that is an interesting idea. you could plastidip just a couple of mm's on either end of the spring.