"bad" springs in Model F keyboard?

User avatar
Wazrach

02 Sep 2019, 16:21

So after flossing the springs in my 4980 Model F, I woke up the next day to find some of the keys weren't working. I decided to open the keyboard yet again and switched out most of the springs for the springs from this 1984 UK Model F I disassembled a few months ago. When I first got that keyboard, the feel was somewhat quiet and it wasn't very snappy or satisfying to use. I attributed this to the condition of the keyboard, as the foam had completely disintegrated.

After putting them in this keyboard, it seems to be the springs. I find this really, really unusual. They're not that clicky, and some of them feel near-linear. Kind of a shame that I wasted this time opening the keyboard to put these shitty springs in, but I thought it would be worth talking about it. I know the springs and flippers differ between models, both physically and in terms of sound. Is it possible these are just "bad" springs out of the factory? They're clean, shiny and have no rust.

Fkazim

02 Sep 2019, 16:39

Never heard of or even experienced bad springs on any IBM Model F. I have however come across some slightly softer springs and I always thought it was due to having something heavy set on some of the keys over the years whilst in storage effectively softening the springs in their compressed position presumably from the previous owners/companies. But now you are also bringing this up I am starting to thing there is more to it then what I first thought.

User avatar
Wazrach

02 Sep 2019, 17:11

Fkazim wrote:
02 Sep 2019, 16:39
Never heard of or even experienced bad springs on any IBM Model F. I have however come across some slightly softer springs and I always thought it was due to having something heavy set on some of the keys over the years whilst in storage effectively softening the springs in their compressed position presumably from the previous owners/companies. But now you are also bringing this up I am starting to thing there is more to it then what I first thought.
Perhaps something WAS sitting on top of it for years. Yeah, these springs are shit.

I've also noticed more or less every time I do foam replacements, a few keys tend to feel like this as well. It's got nothing to do with compression.

Fkazim

02 Sep 2019, 17:53

Wazrach wrote:
02 Sep 2019, 17:11
Fkazim wrote:
02 Sep 2019, 16:39
Never heard of or even experienced bad springs on any IBM Model F. I have however come across some slightly softer springs and I always thought it was due to having something heavy set on some of the keys over the years whilst in storage effectively softening the springs in their compressed position presumably from the previous owners/companies. But now you are also bringing this up I am starting to thing there is more to it then what I first thought.
Perhaps something WAS sitting on top of it for years. Yeah, these springs are shit.

I've also noticed more or less every time I do foam replacements, a few keys tend to feel like this as well. It's got nothing to do with compression.
Yeah you are probably right some of the keys on one of my IBM Model F XT's went a little soft too after being disassembled. The keys were ESC, 1, 2, 3 not really sure why this happens to some Model f's and some it doesn't happen to at all. Also I have had some soft keys on the numpad before.

By far the biggest problem I have had with my Model F's is dust getting onto the Capacitive PCB. For example I would open up my Model F's and leave the pcb in the open for like 20-30mins and few specs of dust land on the PCB and the say I click backspace it would also click + or whatever the key is next to the pad that has dust on it.

Another the other thing I have experienced is some keys that have dust on the pads stay pressed also. I know it is dust as when I disassemble the keyboard and clean the PCB the problem goes. Please let me know it you have experienced anything like this.

Thanks.

User avatar
Muirium
µ

02 Sep 2019, 17:55

Better pony up for some of Ellipse’s fresh unicorn springs. (Someone ought to test them as spares at least.)

I’ve had bent springs in Model Fs. My Kishsaver had one, if I recall, which I switched out the moment I got my eager, sweaty paws on it. Model F is far from immune to wear and tear and general ageing. They’re all so oooold after all!

User avatar
Wazrach

02 Sep 2019, 18:21

Fkazim wrote:
02 Sep 2019, 17:53
Wazrach wrote:
02 Sep 2019, 17:11
Fkazim wrote:
02 Sep 2019, 16:39
Never heard of or even experienced bad springs on any IBM Model F. I have however come across some slightly softer springs and I always thought it was due to having something heavy set on some of the keys over the years whilst in storage effectively softening the springs in their compressed position presumably from the previous owners/companies. But now you are also bringing this up I am starting to thing there is more to it then what I first thought.
Perhaps something WAS sitting on top of it for years. Yeah, these springs are shit.

I've also noticed more or less every time I do foam replacements, a few keys tend to feel like this as well. It's got nothing to do with compression.
Yeah you are probably right some of the keys on one of my IBM Model F XT's went a little soft too after being disassembled. The keys were ESC, 1, 2, 3 not really sure why this happens to some Model f's and some it doesn't happen to at all. Also I have had some soft keys on the numpad before.

By far the biggest problem I have had with my Model F's is dust getting onto the Capacitive PCB. For example I would open up my Model F's and leave the pcb in the open for like 20-30mins and few specs of dust land on the PCB and the say I click backspace it would also click + or whatever the key is next to the pad that has dust on it.

Another the other thing I have experienced is some keys that have dust on the pads stay pressed also. I know it is dust as when I disassemble the keyboard and clean the PCB the problem goes. Please let me know it you have experienced anything like this.

Thanks.
That's probably the reason I had to disassemble the keyboard in the first place. I'm guessing some fine bits of fluff from the paracord strands made their way into the assembly, as certain keys stopped working for whatever reason.

I think my biggest issue isn't the soft springs, it's the DAMN SPACEBAR. It sounds ATROCIOUS. I need to dampen the posts with neoprene pads, otherwise it makes a horrendous rattly sound. I wrapped the stabiliser barrel in electrical tape, hoping it would alleviate the issue, but it didn't make a dent.

User avatar
Wazrach

02 Sep 2019, 18:26

Since the spacebar is the most important part, I'd honestly have a stock assembly with disintegrated foam over this. The stock spacebar sounds so good...

User avatar
Wazrach

02 Sep 2019, 23:08

Well, I switched out the springs for the springs from a 1986 UK Model F. I forgot how high-pitched these ones were! The ping has the highest pitch I've heard! :P

Sounds and feels pretty good now at least.

User avatar
Weezer

03 Sep 2019, 02:35

I've had bad springs that make an inordinate amount of high pitched squeaking or buzzing or are a different pitch than the other springs. The click is created by the flipper slapping down though, not the spring. You can make it flip down and click as it would inside the keyboard just by holding a key down to the flipper spring on your desk without the black plastic housing. If the keys aren't clicking when you press the keys then there was/is an issue preventing the flippers from being pressed down or returning properly. Usually that's caused by a bad seating of the flipper or the keycap, but I suppose it could be caused by low tension provided by the spring. It's possible that after sitting for many years, a layer of corrosion or rust could weaken the integrity of the spring to the point where it's not providing enough tension after several key presses or something had been sitting on the keys for a long period of time similarly weakening them.

User avatar
fohat
Elder Messenger

03 Sep 2019, 14:29

Wazrach wrote:
02 Sep 2019, 18:21

fine bits of fluff from the paracord strands
This detail may be significant. I tried using these instead of floss but didn't like it at all. The character of the material is quite different in several ways.

I really like the open-weave floss because it is very airy and doesn't do anything but damp the overtones.

Last, the length of the segment is important. It has to be more than half the length of the spring because they buckle in the middle, but if it is even the tiniest bit too long, it may interfere or even not allow the key to work at all.

User avatar
Wazrach

03 Sep 2019, 15:12

fohat wrote:
03 Sep 2019, 14:29
Wazrach wrote:
02 Sep 2019, 18:21

fine bits of fluff from the paracord strands
This detail may be significant. I tried using these instead of floss but didn't like it at all. The character of the material is quite different in several ways.

I really like the open-weave floss because it is very airy and doesn't do anything but damp the overtones.

Last, the length of the segment is important. It has to be more than half the length of the spring because they buckle in the middle, but if it is even the tiniest bit too long, it may interfere or even not allow the key to work at all.
I'll probably try actual floss if I do it again. I realise it's a much more sensitive mod than it might seem at first. I spent a lot of time adjusting the length of the strands or replacing them, as the key feel wasn't 100%.

I don't think I can bring myself to silence the character of the Model F. The singing can be distracting when gaming, but I'd rather that over removing it completely.

User avatar
Wazrach

03 Sep 2019, 15:16

Weezer wrote:
03 Sep 2019, 02:35
I've had bad springs that make an inordinate amount of high pitched squeaking or buzzing or are a different pitch than the other springs. The click is created by the flipper slapping down though, not the spring. You can make it flip down and click as it would inside the keyboard just by holding a key down to the flipper spring on your desk without the black plastic housing. If the keys aren't clicking when you press the keys then there was/is an issue preventing the flippers from being pressed down or returning properly. Usually that's caused by a bad seating of the flipper or the keycap, but I suppose it could be caused by low tension provided by the spring. It's possible that after sitting for many years, a layer of corrosion or rust could weaken the integrity of the spring to the point where it's not providing enough tension after several key presses or something had been sitting on the keys for a long period of time similarly weakening them.
There are a number of factors that contribute to the F's key feel. I'm pretty certain those bad springs were caused by something pressing against them for a LONG time. I worry that keyboards in the mail will meet a similar fate, but that never seems to be the case, thankfully.

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