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Posted: 14 May 2017, 12:15
by Laser
t!ng wrote: What if one silenced the sound of the spring hitting the barrel? Couldn't you just tape a little rubber band on the inside?
Finally, a potentially practical answer :)

Re: Buckling spring silencing

Posted: 14 May 2017, 15:49
by Techno Trousers
t!ng wrote:What if one silenced the sound of the spring hitting the barrel? Couldn't you just tape a little rubber band on the inside?
If my idea of the hole plus optional rubber or silicone plug works to dampen the rebound of the flipper, it seems a similar hole and plug could be made in the side of the barrel. I hope lot_lizard is watching this thread--there are a lot of experimentation opportunities here for prototyping.

Posted: 14 May 2017, 16:02
by fohat
Techno Trousers wrote:
it seems a similar hole and plug could be made in the side of the barrel.
You think the spring buckles in the same way and hits the same spot on the inside of the barrel every time?

Posted: 14 May 2017, 16:32
by Laser
Just cover a larger area (as in the whole barrel inside) ?

Posted: 14 May 2017, 16:45
by fohat
Laser wrote:
Just cover a larger area (as in the whole barrel inside) ?
Reduce the internal diameter of the barrel? I think that would dramatically impact the buckling of the spring.

Posted: 14 May 2017, 16:47
by Laser
It can be tested, that's all I'm saying :)

Re: Buckling spring silencing

Posted: 14 May 2017, 18:05
by Techno Trousers
fohat wrote:
Techno Trousers wrote:
it seems a similar hole and plug could be made in the side of the barrel.
You think the spring buckles in the same way and hits the same spot on the inside of the barrel every time?
Not the exact same spot, but definitely the same general area. I'm pretty sure that's why the part of the stem inside the barrel is sculpted the way it is: for guiding the spring's direction. I still want to see the mechanism working inside a transparent barrel, though.

Posted: 14 May 2017, 20:33
by DMA
t!ng wrote: What if one silenced the sound of the spring hitting the barrel? Couldn't you just tape a little rubber band on the inside?
Looks like dental floss mod takes care of that. Quickly checked - indeed, dental floss makes keydown quieter too :)

Posted: 14 May 2017, 21:12
by fohat
DMA wrote:
t!ng wrote:
Couldn't you just tape a little rubber band on the inside?
Looks like dental floss mod takes care of that.
I remember somebody trying a little piece of rubber band in place of the floss, but my experience is that rubber bands deteriorate into something nasty after a couple of years.

Melvang uses one strand from the inside of parachute cord, but that seems very heavy to me.

Posted: 14 May 2017, 21:19
by Laser
DMA wrote:
t!ng wrote: What if one silenced the sound of the spring hitting the barrel? Couldn't you just tape a little rubber band on the inside?
Looks like dental floss mod takes care of that. Quickly checked - indeed, dental floss makes keydown quieter too :)
Where did you put it? Inside the spring (the old, known solution) or inside the plastic barrel, on the side the spring buckles? (in the latter case, the permanent solution is trickier in that you would need to fix the material, rubber or floss, so that it stays there) Maybe some very thin rubber cylinder with the same diameter as the barrel ...

Posted: 14 May 2017, 21:32
by DMA
Laser wrote:
Where did you put it? Inside the spring (the old, known solution) or inside the plastic barrel, on the side the spring buckles? (in the latter case, the permanent solution is trickier in that you would need to fix the material, rubber or floss, so that it stays there) Maybe some very thin rubber cylinder with the same diameter as the barrel ...
Standard dental floss mod - inside the spring. Not sure - may be the spring doesn't even hit the barrel normally, it's just part of the stored energy is spent on bending the floss and the flipper twacks the PCB with less force hence quieter.
Hard to see inside, y'know. The sound is there, but what exactly produces it is a mystery not easily solved. I don't have a small microphone to connect to the scope and record waveforms.
If someone here can explain to me how to make this sampling rig - I can try. But right now I can't even think how to approach this to get meaningful results.

Posted: 14 May 2017, 22:12
by Laser
Just to be clear, I think the solution you propose in this thread is great - and - when coupled with the dental floss mod, it may be enough to get the keyboard silenced. T!ng's idea seems to be trying to take care of the remaining source of sound (if there is any, i.e. if indeed the spring, when buckled, hits the barrel's inside) and I guess it's open for general debate/testing, you don't need to feel pressured to test it or anything :) But I think it may be easier to just test various "solutions" than to create extensive waveforms measurements or theoretical sound modelling of the spring-in-the-barrel behavior.

Posted: 14 May 2017, 22:57
by DMA
I don't mind testing. But you need to have some objective measurements - otherwise it's a slippery slope to audiophilia.

I'm pretty sure there is a simple testing apparatus for this. I just don't know about it and can't invent it on the spot.

Posted: 14 May 2017, 23:28
by Mr.Nobody
I don't know how to silence it, but I know how to make it louder, as to AT; just get the mat out; no mat between barrel bases and the metal plate, so the keyboard will be as loud as a machine gun.

Posted: 15 May 2017, 10:19
by cookie
This thread sounds to me like "I have a very loud Oldtimer with a V8 engine and wan't to silence it down till it sounds like a Tesla"

You don't go BS if you can't take the sound. You'd be much happier in Type-S land :)

Posted: 15 May 2017, 11:30
by Laser
The impossible is overrated :P

Posted: 15 May 2017, 11:32
by seebart
cookie wrote: This thread sounds to me like "I have a very loud Oldtimer with a V8 engine and wan't to silence it down till it sounds like a Tesla"

You don't go BS if you can't take the sound. You'd be much happier in Type-S land :)
Right, doesn't make any sense to me either.

Posted: 15 May 2017, 17:57
by DMA
seebart wrote:
cookie wrote: This thread sounds to me like "I have a very loud Oldtimer with a V8 engine and wan't to silence it down till it sounds like a Tesla"

You don't go BS if you can't take the sound. You'd be much happier in Type-S land :)
Right, doesn't make any sense to me either.
Gentlemen,
BS has tactile feedback superior to anything around (except beamspring - that plate kickback is absolutely amazing and cannot be beat. Notice though that beamspring is significantly quieter). I have not tried topre - but it being rubber domes I expect it to SUCK.
I don't mind the sound - but I want to be able to use BS in the office. And since I don't have a personal office - the sound will be a problem.

And yeah, loud engines also suck. There's nothing glorious in the sound of the metal (and your ears, too) being raped.

Posted: 16 May 2017, 00:31
by drevyek
If you put a bit of carbon on the spring (rub a pencil on it), and then put a small slip of paper in the barrel, you'll be able to see where the spring contacts the paper. If you take a couple samples, I suspect they will all contact at about the same place. A dab of silicon there would be interesting to try.

The floss mod works only by reducing the reverberation, which reduces the noise of the switch indirectly. I don't think it has much to do with reducing the force that the hammer strikes down. It would depend on what happens to the tactile moment when you add floss: does it go up or down? (Maybe a job for Haata?) Too much floss makes the spring too rigid and unable to actually buckle (which is why you can't overflow the spring- the keycap compacts the floss down into the spring).

Something I would find interesting is to dampen the bottoming out sound. Where does the keycap stop? is it inside the barrel? or is it on the lip? A bit of something there would be interesting to hear the difference. The topping out impacts the clip at the very bottom of the stem- a dab or o-ring there might have an effect too.

Re: Buckling spring silencing

Posted: 16 May 2017, 01:34
by Techno Trousers
I'm pretty sure bottom out is happening when the bottom of the stem top comes into contact with the lip of the barrel. If so, maybe a silicone ring adhered the top of a slightly shorter barrel would do the trick in dampening that.

For you guys who don't see the point in this, think about choice. If lot_lizard or others are successful at making new capacitive buckling spring keyboards in the future, it would be great to have a quieter option for those who need/desire it. I'm with DMA in that the tactility of CBS is awesome, and that it's the most important part of the feedback I get. I really do get as much enjoyment typing with my earbuds in as I do when I can hear it clattering away.

Posted: 16 May 2017, 12:26
by Laser
BTW, I tried the dental floss mod with a spring ... but without the floss, by using instead a ~2mm-wide strip cut from a very thin white rubber sheet (1 mm thick - from a 2-layer mousepad) and the pinging sound is eliminated completely. Of course there is still a clacking sound, but it's nicer (not *so* noisy) - I'm thinking to mod the entire keyboard (a Model F Bigfoot) like this.

Posted: 16 May 2017, 12:45
by snoopy
Some years ago I also did some experiments with thin rubberband instead of floss... But it affected the feel too much. It just felt not right.

Posted: 16 May 2017, 12:52
by Laser
snoopy wrote: Some years ago I also did some experiments with thin rubberband instead of floss... But it affected the feel too much. It just felt not right.
The single key mod feels quite nice, both in sound and feel - will see what happens after modding the whole keyboard and after some use time :)

Posted: 20 May 2017, 19:54
by Ellipse
Yep the flipper photo DMA posted is just the styrofoam case as the background. Taken with my Nikon DSLR.

Much of the actuation sound comes from the slap of the flipper directly against the capacitive PCB. I have noticed lower sound volume with extra thick inner foam, though it makes reassembly more difficult.

Posted: 20 May 2017, 21:36
by DMA
Ellipse wrote: Much of the actuation sound comes from the slap of the flipper directly against the capacitive PCB.
My observations match.
Flippers on mylar pad over the rubber membrane are ~9dB quieter than over PCB - but tactility is the same.

Distance flipper flies also affects noise a lot. larger silicone beads dampen the actuation sound significantly - but they also reduce tactility noticeably.

Posted: 22 May 2017, 22:12
by drevyek
Laser wrote:
snoopy wrote: Some years ago I also did some experiments with thin rubberband instead of floss... But it affected the feel too much. It just felt not right.
The single key mod feels quite nice, both in sound and feel - will see what happens after modding the whole keyboard and after some use time :)
This this with a thin rubber band, cut down to the size of the spring, and inserted inside, in the same way as the floss mod? I've seen it done with string, but never with anything as rigid as a rubber band. What diameter/size of rubber band?
DMA wrote: Distance flipper flies also affects noise a lot. larger silicone beads dampen the actuation sound significantly - but they also reduce tactility noticeably.
I'm surprised that the tactility is affected by the flipper's travel. I had thought the tactility came from the spring collapsing, not from anything to do with the hammer. What does it feel like now? More linear, or just less jarring? Does the weighting change?

Posted: 22 May 2017, 22:45
by DMA
drevyek wrote: I'm surprised that the tactility is affected by the flipper's travel. I had thought the tactility came from the spring collapsing, not from anything to do with the hammer. What does it feel like now? More linear, or just less jarring? Does the weighting change?
It becomes ~2 dimes lighter, and the the dip becomes less pronounced. Looks like the spring is more bent at rest (because flipper is halfway pressed) and collapses earlier. Activation point moves ~1mm higher, keeps pretty consistent. "More linear" describes it pretty fairly.

Posted: 23 May 2017, 10:52
by Laser
drevyek wrote:
Laser wrote:
snoopy wrote: Some years ago I also did some experiments with thin rubberband instead of floss... But it affected the feel too much. It just felt not right.
The single key mod feels quite nice, both in sound and feel - will see what happens after modding the whole keyboard and after some use time :)
This this with a thin rubber band, cut down to the size of the spring, and inserted inside, in the same way as the floss mod? I've seen it done with string, but never with anything as rigid as a rubber band. What diameter/size of rubber band?
Well, the thing is that this rubber was the same I used to make my own Topre silencing rings, i.e. this is from a very thin (around or under 1mm), very "non-rigid" rubber sheet - I simply cut a 2mm-wide strip with the approx. length of the spring and yes, I used it exactly as the floss mod.

Posted: 24 May 2017, 13:44
by MrDuul
So this or Dental floss?

Posted: 24 May 2017, 14:32
by Laser
MrDuul wrote: So this or Dental floss?
Try both? More options, more chances to get closer to what you want ;)