Why do you need foam on your model f?

[Rezene]

I just spent the good part of the day restoring my model f xt. I took it apart and the foam was terrible. Super sticky and barely even there. I took it out and cleaned everything off, the only problem was that I don't have any spare foam so I tried to do it without any foam and see what happened. When I put it back together it feels way smoother probably just because I cleaned everything and the sound still sounds great. It seems little more hollow but not bad.
The only problem is the enter key; when you press it slowly, it is sometimes delayed. If you press it hard it acts normal. It sounds like the spring buckles and it takes a second for the flipper to hit the pcb. If anyone has any ideas on what is causing that I would like to hear it. It could be the lack of foam I am not sure. It is only happening on one key though so I don't know how the foam could be causing it. I am overall very happy with it and am not planning on making a replacement foam any time in the future unless I need to for the enter key to work properly. Please tell me your experiences with the foam and if it changed your key feel at all.

[Anakey]

the foam would help keep the barrels pressed down onto the pcb. even though the barrels have a small raised bud that fits through the barrel plate, it does not stop the barrel moving vertically up and down. If there is too much of a gap between the barrel and the pcb there is a chance that the flipper could be dislodged from the indent where it is normally and could then get damaged when pressed again.

[Fkazim]

The main purpose of the foam is to stop the key barrels from wobbling because if they wobble the flippers can become dislodged meaning you will lose the click and the switches will stop functioning. I would just make a new mat its really easy. get some 3mm neoprene foam and some leather hole punches lay the barrel plate on top of the foam mark out the holes cut punch them out using the leather hole punch. Then use clamps to reassemble the assembly there are plenty of guides how to reassemble Model F's.

Hope that helps.

[Rezene]

The main purpose of the foam is to stop the key barrels from wobbling because if they wobble the flippers can become dislodged meaning you will lose the click and the switches will stop functioning. I would just make a new mat its really easy. get some 3mm neoprene foam and some leather hole punches lay the barrel plate on top of the foam mark out the holes cut punch them out using the leather hole punch. Then use clamps to reassemble the assembly there are plenty of guides how to reassemble Model F's.

Hope that helps.

Yea I will do that soon I was just confused because a lot of people make it out that having bad foam completely ruins a model f and I can't notice a difference; maybe its just because I've never tried good foam. Some barrels are wobbling a small amount now that I checked.

[Anakey]

The reason why bad foam ruins it is because the disintegrated foam gets in between the flippers and the pcb and then affects the capacitance which would then cause keys to not register properly.

[Fkazim]

Bad Model F foam doesn't necessarily completely ruin the key feel but the problems that could arise are that some of the degraded foam could get under some of the flippers. This will cause some keys to become unresponsive or stay pressed when you let go. Another less major problem is you might have degraded foam falling out the bottom of the keyboard with the Model F XT in particular as there is a gap around the front edge of the bottom metal case. Another problem I found when putting Model M keycaps on my Model F AT with degraded foam the stabilised Model M keys did not go down smoothly because the Model M keycaps rely on the barrels being solid for the rod stabalisers to slide freely in the inserts sorry if this is too much info but it might be helpful for you or someone else.

If you want to know anything else about Model F's or M's as well just let me know

[Wazrach]

Foam is extremely important. Every Model F is different in terms of feel and sound, but generally you can tell straight away when the foam is bad. Several UK Model F XTs I've bought all had a type of foam with a white "skin" on one side, but this variety always disintegrates with age. With two of the three UK models, simply removing the keycaps was enough to "upset" the disintegrated foam, ruining the key feel and sound - especially in the center row of keys. You'll hear the sound is "thwackier", with a weak click and bottom out sound.

Finding a suitable replacement material isn't easy. Ideally, you want something 2-3mm thick, but very soft and compressible. You'll note the original material moulds to the shape of the barrels. You want a material which will do the same, without making reassembly too difficult.

If you're in the US, you're in luck. McMaster Carr sell 2mm and 3mm, very soft foam which should be close to the original material. Unfortunately for people in the UK, like me, you can't buy anything like this "off the shelf". I've approached multiple foam companies and all but one ignored me.

[Anakey]

I used left over underlay for laminate floorboards, it has the right thickness and compressibility needed.

[Wazrach]

I used left over underlay for laminate floorboards, it has the right thickness and compressibility needed.

Hiya, could you please show it?

[SneakyRobb]

Hi,


https://patents.google.com/patent/US427 ... d&sort=old

Here is the beamspring patent. The beamspring has the same foam layer as the model f.

" Further, a key plate 73 is employed to support the key modules 11 and includes a foam layer 75 to help reduce acoustic noise and to prevent dirt contamination. The foam layer 75 also holds the key modules 11 against the pad card 13 to assure constant and uniform spacing of the fly plate 15 (FIG. 1) from the pad card 13. "

[Rezene]

Foam is extremely important. Every Model F is different in terms of feel and sound, but generally you can tell straight away when the foam is bad. Several UK Model F XTs I've bought all had a type of foam with a white "skin" on one side, but this variety always disintegrates with age. With two of the three UK models, simply removing the keycaps was enough to "upset" the disintegrated foam, ruining the key feel and sound - especially in the center row of keys. You'll hear the sound is "thwackier", with a weak click and bottom out sound.

Finding a suitable replacement material isn't easy. Ideally, you want something 2-3mm thick, but very soft and compressible. You'll note the original material moulds to the shape of the barrels. You want a material which will do the same, without making reassembly too difficult.

If you're in the US, you're in luck. McMaster Carr sell 2mm and 3mm, very soft foam which should be close to the original material. Unfortunately for people in the UK, like me, you can't buy anything like this "off the shelf". I've approached multiple foam companies and all but one ignored me.

I already bought some neoprene 2mm foam before reading this off Amazon hopefully it does its job good enough but I will buy from McMaster in the future. thanks for the info. I think Im not noticing a difference because the old foam was almost completely gone anyways

[kmnov2017]

I have no foam on one of my Model Fs. The keyboard works and sounds great. viewtopic.php?f=7&t=21888&p=444524&hili ... on#p444524

When compared to the another Model F I own, that does have a foam, the sound on the one without a foam is slightly more pingy.

Personally, I like the one without the foam, but then again thats a matter of preference.

[Wazrach]

I have no foam on one of my Model Fs. The keyboard works and sounds great. viewtopic.php?f=7&t=21888&p=444524&hili ... on#p444524

When compared to the another Model F I own, that does have a foam, the sound on the one without a foam is slightly more pingy.

Personally, I like the one without the foam, but then again thats a matter of preference.

Could you please upload a sound test of that? I'd be interested in hearing it.

It's worth noting that pinginess is to do with the springs, and not usually the condition of the board. I don't know why, but the pitch and volume of the ping differs with every Model F keyboard. It's fascinating to me, but I never seem to get the pingy ones.

In my experience, Model F keyboards don't feel nice after opening them, even when you don't change the foam. I think this may be to do with hammering the plates apart and back together, which may change the shape of the front plate. I suppose if you have bent the tabs out of alignment rather than sliding the plates apart, that would explain why you haven't experienced a change in key feel.

[fohat]

It's worth noting that pinginess is to do with the springs, and not usually the condition of the board. I don't know why, but the pitch and volume of the ping differs with every Model F keyboard. It's fascinating to me, but I never seem to get the pingy ones.

In my experience, Model F keyboards don't feel nice after opening them, even when you don't change the foam. I think this may be to do with hammering the plates apart and back together, which may change the shape of the front plate. I suppose if you have bent the tabs out of alignment rather than sliding the plates apart, that would explain why you haven't experienced a change in key feel.

I will have to take exception to all of this. I don't believe that "pinginess" has much to do with springs and everything to do with the tension and compression in the plates. (That said, "pinginess" can be attenuated by introducing foreign objects into the springs (floss, etc) but the plates have an intimate and taut relationship.)

The assembly is a "sliding force fit" and that is the optimal method, in my opinion. I do use a single slight tap with a hammer to initiate the separation and complete the re-seating of the plates, but the interplay of tension and compression is the magic and the force and sliding is what creates it.

Also, I find it hard to believe that bending and re-bending tabs can successfully re-find a happy place, but I have no intention of risking an experiment.

[Rezene]

I have no foam on one of my Model Fs. The keyboard works and sounds great. viewtopic.php?f=7&t=21888&p=444524&hili ... on#p444524

When compared to the another Model F I own, that does have a foam, the sound on the one without a foam is slightly more pingy.

Personally, I like the one without the foam, but then again thats a matter of preference.

Could you please upload a sound test of that? I'd be interested in hearing it.

It's worth noting that pinginess is to do with the springs, and not usually the condition of the board. I don't know why, but the pitch and volume of the ping differs with every Model F keyboard. It's fascinating to me, but I never seem to get the pingy ones.

In my experience, Model F keyboards don't feel nice after opening them, even when you don't change the foam. I think this may be to do with hammering the plates apart and back together, which may change the shape of the front plate. I suppose if you have bent the tabs out of alignment rather than sliding the plates apart, that would explain why you haven't experienced a change in key feel.

I recorded a sound test of my board with no foam https://www.youtube.com/watch?v=OrF6uQr6uSc sorry about the recording quality (the board cost more than the phone did) but hopefully it gets an idea of the sound. I hear very little pinging especially with the feet up

[Wazrach]

It's worth noting that pinginess is to do with the springs, and not usually the condition of the board. I don't know why, but the pitch and volume of the ping differs with every Model F keyboard. It's fascinating to me, but I never seem to get the pingy ones.

In my experience, Model F keyboards don't feel nice after opening them, even when you don't change the foam. I think this may be to do with hammering the plates apart and back together, which may change the shape of the front plate. I suppose if you have bent the tabs out of alignment rather than sliding the plates apart, that would explain why you haven't experienced a change in key feel.

I will have to take exception to all of this. I don't believe that "pinginess" has much to do with springs and everything to do with the tension and compression in the plates. (That said, "pinginess" can be attenuated by introducing foreign objects into the springs (floss, etc) but the plates have an intimate and taut relationship.)

The assembly is a "sliding force fit" and that is the optimal method, in my opinion. I do use a single slight tap with a hammer to initiate the separation and complete the re-seating of the plates, but the interplay of tension and compression is the magic and the force and sliding is what creates it.

Also, I find it hard to believe that bending and re-bending tabs can successfully re-find a happy place, but I have no intention of risking an experiment.

I know it's to do with tension, but the springs are definitely responsible as well. The springs in this NOS 5155 Model F barely reverberate. I also have a UK Model F that produced a very quiet ping when assembled. I've experimented multiple times, putting different springs in the same keyboard. It's definitely to do with the springs themselves, as well as the tension. I'd say tension is responsible for when the ping "rings".

I can't think of another reason why the boards feel like shit after putting them together. I'm going to assume the hammering apart and hammering back into place is what's possibly bending the metal and intorducing an inconsistent feel to the board. It's driving me nuts. It wasn't as bad on the first AT I got, where I bent the tabs back instead of hammering the plates apart.

[Wazrach]

I have no foam on one of my Model Fs. The keyboard works and sounds great. viewtopic.php?f=7&t=21888&p=444524&hili ... on#p444524

When compared to the another Model F I own, that does have a foam, the sound on the one without a foam is slightly more pingy.

Personally, I like the one without the foam, but then again thats a matter of preference.

Could you please upload a sound test of that? I'd be interested in hearing it.

It's worth noting that pinginess is to do with the springs, and not usually the condition of the board. I don't know why, but the pitch and volume of the ping differs with every Model F keyboard. It's fascinating to me, but I never seem to get the pingy ones.

In my experience, Model F keyboards don't feel nice after opening them, even when you don't change the foam. I think this may be to do with hammering the plates apart and back together, which may change the shape of the front plate. I suppose if you have bent the tabs out of alignment rather than sliding the plates apart, that would explain why you haven't experienced a change in key feel.

I recorded a sound test of my board with no foam https://www.youtube.com/watch?v=OrF6uQr6uSc sorry about the recording quality (the board cost more than the phone did) but hopefully it gets an idea of the sound. I hear very little pinging especially with the feet up

Thanks for recording that. It definitely doesn't sound as bad as I was expecting. It's hard to tell from the quality, but it does sound a bit loose in the middle row.

[kcrimson]

I can't think of another reason why the boards feel like shit after putting them together. I'm going to assume the hammering apart and hammering back into place is what's possibly bending the metal and intorducing an inconsistent feel to the board. It's driving me nuts. It wasn't as bad on the first AT I got, where I bent the tabs back instead of hammering the plates apart.

I'm very anal about how my keyboards feel and sound and I like to press keys for no reason all the damn time (to the point where my fingers start hurting) and yet I haven't noticed a single difference in my F XT when I disassembled and reassembled it. If it's worth noting, my keyboard had that black foam which was still spongy and I slid the plates apart with my hands and put them together with clamps and a few taps of a hammer with a stick.

Are you sure you're not just imagining it? I think when you try your hardest and spend a lot of money to make something perfect your brain will always try to find some kind of fault in it, and you'll think that nobody else's setup has these kinds of faults.

[Rezene]

I can't think of another reason why the boards feel like shit after putting them together. I'm going to assume the hammering apart and hammering back into place is what's possibly bending the metal and intorducing an inconsistent feel to the board. It's driving me nuts. It wasn't as bad on the first AT I got, where I bent the tabs back instead of hammering the plates apart.

I'm very anal about how my keyboards feel and sound and I like to press keys for no reason all the damn time (to the point where my fingers start hurting) and yet I haven't noticed a single difference in my F XT when I disassembled and reassembled it. If it's worth noting, my keyboard had that black foam which was still spongy and I slid the plates apart with my hands and put them together with clamps and a few taps of a hammer with a stick.

Are you sure you're not just imagining it? I think when you try your hardest and spend a lot of money to make something perfect your brain will always try to find some kind of fault in it, and you'll think that nobody else's setup has these kinds of faults.

I feel like a lot of the time differences in key feel can be attributed to placebo. that's why I made this post because I didn't notice a difference at all and thought most people say you need a foam because they expect an improvement with foam and worsening without. people have made good points and reducing barrel wobble is definitely worth putting foam in imo

[Darkshado]

I'm going to assume the hammering apart and hammering back into place is what's possibly bending the metal and introducing an inconsistent feel to the board. It's driving me nuts. It wasn't as bad on the first AT I got, where I bent the tabs back instead of hammering the plates apart.

My current method to separate F plates is to bend back the locking tab, then set one end of the top plate on a piece of wood and gently tap the protruding parts of the top plate with another piece of wood or a rubber mallet so it slides out.

To assemble them back together I use multiple small spring loaded clamps (similar to these) to hold everything together, then a long pipe clamp (similar to this) with a crank handle on one end to slide the bottom plate into the tab notches. Bend the locking tab back into place by hand or with pliers.

Hammering risks twisting the tabs and warping the plates.

[Wazrach]

I'm going to assume the hammering apart and hammering back into place is what's possibly bending the metal and introducing an inconsistent feel to the board. It's driving me nuts. It wasn't as bad on the first AT I got, where I bent the tabs back instead of hammering the plates apart.

My current method to separate F plates is to bend back the locking tab, then set one end of the top plate on a piece of wood and gently tap the protruding parts of the top plate with another piece of wood or a rubber mallet so it slides out.

To assemble them back together I use multiple small spring loaded clamps (similar to these) to hold everything together, then a long pipe clamp (similar to this) with a crank handle on one end to slide the bottom plate into the tab notches. Bend the locking tab back into place by hand or with pliers.

Hammering risks twisting the tabs and warping the plates.

That's what I do. :/ Seriously. I don't know why they feel so bad every time. It's definitely not placebo.

[Rezene]

I bought another xt off of ebay that I got really lucky with and it has prestine foam. I cant say if it is just that or the lack of rust/cleaner in general, but it feels much smoother and the tactility is much more pronounced. typing on the board with no foam feels almost linear. The sound is much more consistent throughout the board. I think replacing foam is something that is not a must be definitely nice. I don't mind using the other board it feels nice but almost like a different switch. I would choose the foam board if I had to choose one.

[cli]

I used left over underlay for laminate floorboards, it has the right thickness and compressibility needed.

Also used some underlay foams I had leftover. The thin underlay works great, I think it's about 1.25 mm. Thick underlay (2.5 mm with a plastic coating) didn't worked at all, couldn't close the metal plate.