geekhack

geekhack Projects => Making Stuff Together! => DIY Discussions ARCHIVE => Topic started by: msiegel on Thu, 08 October 2009, 18:25:13

Title: AT&T's Patented Model M Reverb Silencer
Post by: msiegel on Thu, 08 October 2009, 18:25:13
check this out!

in the late 1980s, four guys at AT&T got pissed about all the pinging noises and decided to do something about it:

http://www.google.com/patents/about?id=Woc5AAAAEBAJ

edit: see figures 3 and 4 for the best view of the mod.

anyone care to try it?
Title: AT&T's Patented Model M Reverb Silencer
Post by: wellington1869 on Thu, 08 October 2009, 19:11:28
looks interesting, i wonder how much it would really silence it tho. Basically as I understand it they're suggesting some kind of "resin core" inside the spring.

would that flex enough?  Did anyone build a prototype? I'd love to try it out of course.

My own idea for less-ping BS is to make the spring out of a different material (maybe some kid of durable plastic).

Incidentally, I tried wrapping the spring in a thin rubber sheet, didnt work (doesnt have room to buckle at all, even with a very very thin rubber sheet around it).
Title: AT&T's Patented Model M Reverb Silencer
Post by: msiegel on Thu, 08 October 2009, 19:14:53
Quote from: wellington1869;123976
looks interesting, i wonder how much it would really silence it tho. Basically as I understand it they're suggesting some kind of "resin core" inside the spring.

would that flex enough?  Did anyone build a prototype? I'd love to try it out of course.


the patent says that by doing testing, they found that using closed-cell urethane foam for a core, placed right above the foot works best
Title: AT&T's Patented Model M Reverb Silencer
Post by: SCTony on Thu, 08 October 2009, 19:20:40
Nice find msiegel[edit]! How did you happen to find that tidbit?
Title: AT&T's Patented Model M Reverb Silencer
Post by: msiegel on Thu, 08 October 2009, 19:24:28
he reads keyboard-related patents for fun ;D
Title: AT&T's Patented Model M Reverb Silencer
Post by: wellington1869 on Thu, 08 October 2009, 19:37:06
lol it wasnt me, it was mseigal ;)

mseigal, what is closed cell urethane foam? something we can find at home depot? I'd love to try this out.
Title: AT&T's Patented Model M Reverb Silencer
Post by: MsKeyboard on Thu, 08 October 2009, 20:40:08
Webwit,
That's Cool! Thanks
Title: AT&T's Patented Model M Reverb Silencer
Post by: wellington1869 on Thu, 08 October 2009, 21:21:16
Quote from: webwit;123985
If only there was some way (http://lmgtfy.com/?q=closed+cell+urethane+foam) to find out..


thought you didnt trust google, webwit? ;)
Title: AT&T's Patented Model M Reverb Silencer
Post by: Shawn Stanford on Fri, 09 October 2009, 08:15:14
Your standard camping ground pads are made out of this stuff. An appropriately sized piece of piping could be heated and jammed through, which should yield an inch of foam at a go - enough for several test keys.
Title: AT&T's Patented Model M Reverb Silencer
Post by: itlnstln on Fri, 09 October 2009, 08:38:22
I don't think anyone spelled msiegel's name correctly yet in this thread. Remember, kids, "i" before "e" except after "c."
 
Welly, maxlugar has the particular aversion to using Google, IIRC.
Title: AT&T's Patented Model M Reverb Silencer
Post by: msiegel on Fri, 09 October 2009, 09:49:19
thanks, itlnstln :)

ps - maxlugAr
:lol:
Title: AT&T's Patented Model M Reverb Silencer
Post by: itlnstln on Fri, 09 October 2009, 10:07:01
Quote from: msiegel;124090
thanks, itlnstln :)
 
ps - maxlugAr
:lol:

<- Epic fail.
Title: AT&T's Patented Model M Reverb Silencer
Post by: msiegel on Fri, 09 October 2009, 10:18:07
Quote from: itlnstln;124096
<- Epic fail.


it was delightful XD
Title: AT&T's Patented Model M Reverb Silencer
Post by: wellington1869 on Fri, 09 October 2009, 10:43:24
Quote from: Shawn Stanford;124067
Your standard camping ground pads are made out of this stuff. An appropriately sized piece of piping could be heated and jammed through, which should yield an inch of foam at a go - enough for several test keys.


msIEgal, would you like to volunteer? :)  Maybe one of us can sneak up on unsuspecting campers while theyre sleeping and snatch an inch of foam off their sleeping pads...

I'm sure the police will buy our explanation :-D
Title: AT&T's Patented Model M Reverb Silencer
Post by: msiegel on Fri, 09 October 2009, 10:49:51
Quote from: wellington1869;124102
msIEgal, would you like to volunteer? :)  Maybe one of us can sneak up on unsuspecting campers while theyre sleeping and snatch an inch of foam off their sleeping pads...

I'm sure the police will buy our explanation :-D


if we cut it in the shape of a bite mark, no one will suspect ;)
Title: AT&T's Patented Model M Reverb Silencer
Post by: quadibloc on Fri, 09 October 2009, 14:53:19
I think I have some packaging material that looks yellowish-brown and messy which just might be that sort of foam. How I would make cores of it that would just fit inside the springs is not immediately clear, and devices for spraying that sort of foam in walls would both be expensive and unlikely to be applicable to such delicate work as filling a spring.

I suppose a narrow metal tube with a sharpened end might work...
Title: AT&T's Patented Model M Reverb Silencer
Post by: msiegel on Fri, 09 October 2009, 14:59:55
yes, excellent idea. a punch of some sort would be ideal :)
Title: AT&T's Patented Model M Reverb Silencer
Post by: SCTony on Fri, 09 October 2009, 16:25:03
Maybe a leather-working punch? What length would the foam plugs need to be?
http://www.hobbytoolsexpress.com/servlet/the-82/Leather,punch-tools,hand-tools,leather-craft/Detail (http://www.hobbytoolsexpress.com/servlet/the-82/Leather,punch-tools,hand-tools,leather-craft/Detail)
Title: AT&T's Patented Model M Reverb Silencer
Post by: msiegel on Fri, 09 October 2009, 16:29:09
Quote from: SCTony;124182
Maybe a leather-working punch? What length would the foam plugs need to be?
http://www.hobbytoolsexpress.com/servlet/the-82/Leather,punch-tools,hand-tools,leather-craft/Detail (http://www.hobbytoolsexpress.com/servlet/the-82/Leather,punch-tools,hand-tools,leather-craft/Detail)

the patent says they used cores 0.130" in diameter, 0.125" in length.

edit: i wonder if they used the tube from a ball-point pen somehow -- it looks like it's the perfect inside diameter (~3.3mm).

ps - if a 2-part foam mixture were poured *into* a ballpoint pen tube, then maybe the foam would just need to be cut for length, rather than punched out as circles :)

where's clickclack, doesn't he know these sorts of things? :D
Title: AT&T's Patented Model M Reverb Silencer
Post by: SCTony on Fri, 09 October 2009, 16:50:08
That would be 3.3mm- there is a 3 and 4 mm punch in that hobby kit. I used to have a few odds and ends- I'll see if I still have anything this weekend. Any ideas on .125" thick foam sheets?
Title: AT&T's Patented Model M Reverb Silencer
Post by: msiegel on Fri, 09 October 2009, 17:04:47
hmm, it wouldn't take much material to do the job... maybe something similar to this but without adhesive

http://www.thehardwarehut.com/catalog-product.php?p_ref=259852
Title: AT&T's Patented Model M Reverb Silencer
Post by: SCTony on Fri, 09 October 2009, 17:15:50
Or maybe something like this?  1/8" is .125   :http://www.closedcellfoams.com/volara.html (http://www.closedcellfoams.com/volara.html)
Title: AT&T's Patented Model M Reverb Silencer
Post by: msiegel on Fri, 09 October 2009, 17:27:42
Quote from: SCTony;124196
Or maybe something like this?  1/8" is .125   :http://www.closedcellfoams.com/volara.html (http://www.closedcellfoams.com/volara.html)

:D neat, that might work.

i'm no foam guy, but it certainly *sounds* good :)

edit: the closed-cell foam used as packing material in filco tenkeyless boxes is not suitable. the cells are too large, so edges are too rough when cut.
Title: AT&T's Patented Model M Reverb Silencer
Post by: msiegel on Sat, 10 October 2009, 15:49:28
model f test #1: failed.

tried a small piece of dense foam shaved off a yoga block, cut roughly into a cylindrical core and placed inside the spring, right on top of the hammer's mounting peg -- it didn't work.

either the foam was too dense or the core i made was too tall, but it prevented the model f spring from buckling properly. model f springs *are* lighter than model m springs though, so that may also account for some difference.
Title: AT&T's Patented Model M Reverb Silencer
Post by: wellington1869 on Sat, 10 October 2009, 15:53:53
conceptually I dont yet see how this would work. Ie, piece of foam at the bottom of the spring. Would it keep the spring from folding? if it does, you'd lose all tactility and click. What exactly is the foam supposed to accomplish? Prevent the spring's reverberations ("ping")? Doesnt silicon grease work just as well? (It does on my silenced endurapro). Is foam supposed to work better?
Title: AT&T's Patented Model M Reverb Silencer
Post by: wellington1869 on Sat, 10 October 2009, 15:54:32
Quote from: msiegel;124356
model f springs *are* lighter than model m springs though, so that may also account for some difference.


offtopic, but which reminds me, has anyone tried transplanting F springs into an M yet? Are they diff sizes?
Title: AT&T's Patented Model M Reverb Silencer
Post by: msiegel on Sat, 10 October 2009, 15:55:54
i think the diameter is the same, but the length is different?

darn it, i'm sure someone tried this but i can't remember who it was...
Title: AT&T's Patented Model M Reverb Silencer
Post by: msiegel on Sat, 10 October 2009, 15:59:15
Quote from: wellington1869;124358
What exactly is the foam supposed to accomplish? Prevent the spring's reverberations ("ping")? Doesnt silicon grease work just as well? (It does on my silenced endurapro). Is foam supposed to work better?

the idea is the same as with grease: provide a way for the energy of motion to dissipate, besides as a ringing sound :)

they claimed it doesn't change the click, just the ping reverb
Title: AT&T's Patented Model M Reverb Silencer
Post by: wellington1869 on Sun, 11 October 2009, 00:28:29
Quote from: msiegel;124360
i think the diameter is the same, but the length is different?

darn it, i'm sure someone tried this but i can't remember who it was...


hmmm, if diameter is same, spring length can always be cut.  I'll definitely try this when I get some time, since i'm always looking for 'lighter bs' (but I need a normal M layout).

it sounds like a laborious mod, but might be worth it in the end. Would sure be a unique M. ;)

Quote

they claimed it doesn't change the click, just the ping reverb

well i'm curious if anyone gets it working, tho i have to say that silicon grease does accomplish that pretty well.

Loving the m13, really does feel lighter than my 1401.  I guess it would make sense if its based on the same model that the unicomps are based on (since my endurapro also feels lighter than my M)

what i'd really like to do though is transplant F springs into my m13. *drool*.  Maybe a project for when I have a real basement I can set up shop in.
Title: AT&T's Patented Model M Reverb Silencer
Post by: msiegel on Sun, 11 October 2009, 00:41:25
let me know if you try it.

i think exact core height is important -- the patent specifies a height of 0.125" :)

also, they experimented on the model m, so we f owners may be on our own
Title: AT&T's Patented Model M Reverb Silencer
Post by: SCTony on Tue, 17 November 2009, 23:36:25
Well... I have started experimenting with this method. Nothing very precise- just roughing it. I found a yoga mat for cheap and it looked like a good foam for this. I dug out an old leather-punch which yields a plug small enough I can slide it into the springs. I wish it were a tiny bit wider diameter but its pretty close. I loaded 12 springs - the first four on each alpha row. I only spilled the hammers once. It does eliminate the ping pretty effectively. I like the difference- enough to continue experimenting.



I want to try cutting these plugs various lengths - they might be a little long. I also want to try putting htem in the top of the spring (would be a LOT easier mod if that works).  I tried 3 different locations in the springs - low, touching the foot; medium - small gap above the foot; and high - near the middle of the spring. Low and medium were about the same but I had one spring fail to buckle with the high plugs. I tried one spring with lots of foam- it buckled. Anyway, that's all for tonight.

Title: AT&T's Patented Model M Reverb Silencer
Post by: msiegel on Tue, 17 November 2009, 23:54:42
very cool! :D :D thanks for the photos too.
Title: AT&T's Patented Model M Reverb Silencer
Post by: JBert on Wed, 18 November 2009, 15:04:13
Hmmm, it would rock if this could (mostly) silence a model F keyboard...
Title: AT&T's Patented Model M Reverb Silencer
Post by: spuxx on Wed, 18 November 2009, 15:16:53
Does this only prevent the ping after activating the key or also the whole special click noise of a model m?
Title: AT&T's Patented Model M Reverb Silencer
Post by: msiegel on Wed, 18 November 2009, 15:19:14
Quote from: spuxx;133789
Does this only prevent the ping after activating the key or also the whole special click noise of a model m?


just the ping, supposedly :)
Title: AT&T's Patented Model M Reverb Silencer
Post by: ch_123 on Wed, 18 November 2009, 15:27:39
Grease will do pretty much the same job, and is much easier to implement.
Title: AT&T's Patented Model M Reverb Silencer
Post by: spuxx on Wed, 18 November 2009, 15:40:44
Quote from: ch_123;133791
Grease will do pretty much the same job, and is much easier to implement.


Is it just to grease each spring and that will do the job? That would really be much easier if it works, even if it's filthier than dampen the spring with foam.
Title: AT&T's Patented Model M Reverb Silencer
Post by: msiegel on Wed, 18 November 2009, 15:51:19
Quote from: spuxx;133795
Is it just to grease each spring and that will do the job? That would really be much easier if it works, even if it's filthier than dampen the spring with foam.


we should find out about wellington1869's greased unicomp...

i'm curious whether grease stays on the springs :)
Title: AT&T's Patented Model M Reverb Silencer
Post by: ch_123 on Wed, 18 November 2009, 15:55:30
Quote from: spuxx;133795
Is it just to grease each spring and that will do the job? That would really be much easier if it works, even if it's filthier than dampen the spring with foam.

You apply a very small amount to the inside of the keycap stem (both sides that surrond the spring itself). How this works (bare in mind that the grease stays mainly on the stem) is a bit of a mystery to me, but I wouldnt argue with the results.

Oddly enough, the grease treatment is not as effective on the Model F. Not that you'd really want to properly silence a Model F...
Title: AT&T's Patented Model M Reverb Silencer
Post by: Rajagra on Wed, 18 November 2009, 16:59:16
Interesting. I had thought about putting some kind of loose sleeve around the springs (heat-shrink tubing maybe.) I think it could work, but the sleeve would undoubtedly wear out much sooner than the switch. Why did it never occur to me to put something inside the spring?
Title: AT&T's Patented Model M Reverb Silencer
Post by: SCTony on Sat, 05 December 2009, 17:26:12
I found a mini punch set at a local arts&craft store that has an appropriate size punch - 3/32"=2.5mm which seems to be working well.. It was 4 or 5 dollars on sale. I have loaded six or so keys from the top on a model M and it seems to work as well as from the bottom (foot end). So... it's about time to de-ping my model F. I had thought about greasing the springs but I worry about the grease seeping down over time. I certainly wouldn't want it to get down into the model F- it might deteriorate the foam.:pound:
Title: AT&T's Patented Model M Reverb Silencer
Post by: msiegel on Sat, 05 December 2009, 18:58:10
:D :D
i hope it works, a pingless model f would be very cool
Title: AT&T's Patented Model M Reverb Silencer
Post by: JBert on Sun, 06 December 2009, 07:31:22
Quote from: SCTony;139203
I certainly wouldn't want it to get down into the model F- it might deteriorate the foam.:pound:
I wouldn't worry about the foam as the stuff only sits between the barrels and top plate. Instead, the grease may change the capacitance readings of all keys when it would seep onto the PCB pads.
Model M's don't suffer from it as they just need to make contact so they're not comparable.
Title: AT&T's Patented Model M Reverb Silencer
Post by: SCTony on Sun, 06 December 2009, 09:33:53
Good point JBert. I hadn't thought about that.