Texelec's keyboard foam replacements

[snuci]

I truly appreciate that, I just hated to cost you any money or waste more of your time. I'm happy to cover the shipping! :D Since you are sending one of yours maybe you could include an original green one too? My originals from the Compaq are charcoal in color, not green. I don't know if that makes any difference but I'd like to feel it if possible and compare to the samples I'm getting. I know you showed an image compressed before with all three for comparison, but it's hard to "see" the difference.

Let me know if you need my address.

Forget about the money. It's my pleasure to help. I saved your envelope for this very reason but please PM me your address anyway.

 

[VERAULT]

Is there any truth to closed cell foam lasting longer than open cell?

 

[Chuck(G)]

I think it's more a matter of material. Still, if the foam is subject to environmental (e.g. ozone) degradation, I can see where open-cell might have a more limited lifetime.

 

[falter]

Hello kind gentlemen!

OH NO DavidL, please don’t give up on me! I do still <3 love <3 all of you and I greatly appreciate the hard work in testing my pads by all of you and I appreciate the in-depth feedback, greatly. I just saw the posts yesterday, I have been super busy the last few days so I was a bit slow on checking back. I just saw the subscribe to thread option too.

When I did see the posts I also got a little obsessed because the forum was not loading correctly across 4 different browsers. The stylesheet is not loading so reading through the forum in straight HTML without the stylesheet is a little cumbersome. It’s loading in Edge now, so here I am. Anyone having this issue in Firefox? I can’t seem to fix it, cleared cache and cookies and my browser is up to date. Sorry got off topic there.

Anyway, all that said I am reading through and am now on the hunt for new foam. I saw billdeg was using Track-bed about a week or so ago on his website so I was already considering this. I have been digging over here. Now I am contemplating height and hoping to find out exactly what that foam is made of as I would like to buy it in larger sizes, preferably by the roll and not a 1 ¾” wide roll. I know it’s open-cell and according to the Track-bed site it will not quickly deteriorate, however that promotional video appears to be relatively dated. At least that means it shouldn’t be going away anytime soon, right? I’m not ruling it out as I can at least buy it by the sheet.

I will need testers guys, so please don’t give up on me guys! :hugs:

OK, checking my private messages now.

Thanks again for your efforts and excellent customer service.

The only thing that might be an issue with the trackbed foam is cost..m I know from having been a modeler everything in model railroading is $$$

 

[snuci]

Okay Sara, I have pics!

This is an Apple Lisa keyboard that has NOT been refurbished. This is a little extreme. In some cases, the foam has turned to a tar like substance. In other cases, it has turned to dust. This one is the "dust" variety As you can see, this one also needs some clean up on the PCB board and perhaps some rust work.



I have replaced the Caps Lock foam with one of my foam 1/4" foam pads. The first picture is and Caps Lock that is unlocked (normal resting position). The second picture is with the caps lock engaged. It sticks out a ways but because of the ability for it to compact easily, it rests well on the Caps Lock pad.



You can see that in the locked position, there is plenty of travel left to make contact so that was why I was confused with why someone would need a double thick pad for Caps Lock. This is not to say that maybe someone else doesn't need it but I have refurbished 5 keyboards and I still have to do this one and I think I might have another spare. That's a small but decent number of examples. That said, I did buy some replacement key caps from Vintage Micros and they didn't fit. It was from a different type of Lisa keyboard so it is likely there is another type.

Anyway, thought I'd close the loop on this one. Thanks for listening.

 

[sarawill]

Is there any truth to closed cell foam lasting longer than open cell?

I think it's more a matter of material. Still, if the foam is subject to environmental (e.g. ozone) degradation, I can see where open-cell might have a more limited lifetime.

Thanks again for your efforts and excellent customer service.

The only thing that might be an issue with the trackbed foam is cost..m I know from having been a modeler everything in model railroading is $$$

Verault: Yes, there is definitely truth in closed cell lasting longer. In fact, there are varying life spans for different types of open-cell foam. I have been researching this like a mad woman. There are life spans of 1 to 2 years, 5 to 8, 8 to 10 and 12 to 18 and those are just the spans I have seen in my research for open-cell. Needless to say I am going to be aiming for the longest possible span while still having the same feel as the original pads. Closed-cell will last starting at 5 to 8 and for as long as 35 years depending on the many factors. The more dense as well as the chemical makeup and intended use seem to be what dictates this estimated life span. This can include chemicals for UV protection, fire retardants and other factors considered based on use. Closed-cell is used for many different applications ranging from sound-deadening, batting for upholstery many medical uses (like podiatry foam and more) as well as crafting, weather proofing, skid proofing, baffling under flooring and carpet, the list goes on and on. Open-cell can range from packing material to weather stripping, cushioning, also under carpet floors, shoes, crafting, this lists also goes on and on. There are so many different types of foam! It's uncanny.


Chuck(G): You've got that right! Also, storing computers in hot garages and spilling things on the keyboards will effect this life span and deterioration. Personally, my husband and I get most all of our computer from the places where they have been neglected for many years and not necessarily stored properly. We have a Tandy right now that I'm pretty sure had that thick lemon furniture polish all over the inside, including the keyboard. I assume from years of dusting around it and not being careful, or maybe it was one really bad spill that some kid never fessed up to. :D I liked closed-cell for these reasons. But I just think people will keep having issues and even if there aren't issues there will always be that want/need for the correct feel in the key presses. Don't you guys think? I might as well try to get that feel since I am switching foam. Maybe I could provide two different types, long-life versus computer purist? But that is not as cost effective and will add more time to keeping my inventory supplied. We’ll see. Again, I will definitely be considering the life span when I choose the open-cell foam.


falter: I will likely not use Track-bed because I already know it is more dense than the original because of the feedback here. However, I could possibly choose something with the same density if I have to settle for a terrible life span, I want at least 8 to 10 years! I would venture to guess it's lifespan is around 10 to 12 or possibly 12 to 18 years since it's open-cell. Maybe longer if it is stored inside a cool dry area. I know I have seen a lot of crumbling foam on train table set ups at estate sales. I also worry about craft fads, they could reformulate the material at any time and the density changes on me. I can't rely on a certain brand or marketing gimmicks for the material I use. I have to know what it's made of so and it's specs so I can always find the same replacement or I could end up back in the testing phase again.

Sorry my posts are always so long. I’ll try to work on that. Thanks again guys for all your input! I’ll keep you posted. My samples were mailed today. *getting excited over here*

 

[SomeGuy]

Sorry my posts are always so long. I’ll try to work on that.

Anyone that can write more than 140 characters at a time seems to be a rare thing these days. I say keep it up!

Anyway, there is some very good information in this thread. Makes one appreciate what hell a materials engineer must go through. And this is just late 70s/early 80s tech! In the far of year 2018 it must be rocket science all the way.

Electrical capacitance, conductivity, material thickness variations, resulting shape, material longevity, whatever the technical term for "squishiness" is, and so on.

Longevity is certainly something to think about. I recently bought a capacitive keyboard for a system I have. It probably won't even get much use, but it was a good price and otherwise in excellent condition. It would not be the first time I have pulled something out 10 years later to find the item has expired somehow. (But at the rate I am going, in another 10 years I'll probably have turned to goo).

So it is good to get as many of the technical details as possible preserved, because in the future people will need to do this again and again.

 

[sarawill]

Anyway, thought I'd close the loop on this one. Thanks for listening.

Thanks for posting this Snuci! This does look like they are all the same height here and in your photo from post #39. I suppose I'm technically creeping this loop open just a bit again by replying, but I have to know what JJ and Jeremy were talking about with their keyboards before I start with the new batches. If I can avoid making a couple of taller pads per set that would be nice. It would save time in my building and packaging process in the future. I'll send them messages and share the results here for everyone when it's squared away.

 

[sarawill]

Anyone that can write more than 140 characters at a time seems to be a rare thing these days. I say keep it up!

Anyway, there is some very good information in this thread. Makes one appreciate what hell a materials engineer must go through. And this is just late 70s/early 80s tech! In the far of year 2018 it must be rocket science all the way.

Electrical capacitance, conductivity, material thickness variations, resulting shape, material longevity, whatever the technical term for "squishiness" is, and so on.

Longevity is certainly something to think about. I recently bought a capacitive keyboard for a system I have. It probably won't even get much use, but it was a good price and otherwise in excellent condition. It would not be the first time I have pulled something out 10 years later to find the item has expired somehow. (But at the rate I am going, in another 10 years I'll probably have turned to goo).

So it is good to get as many of the technical details as possible preserved, because in the future people will need to do this again and again.

Thanks for the encouragement SomeGuy! I hope this information is helpful to many. :D

 

[drdanj]

This is the stuff I use: http://www.dltpodiatry.co.uk/Padding/polyfoam-5mm.htm

It's polyurethane so should last years and years.

c.f. https://onlinelibrary.wiley.com/doi/pdf/10.1002/jrs.4984

d.

 

[DaveL]

My guess is they probably had problems with the shorter (than 4.5mm) pads and convinced themselves that the double-height pads were the answer when a 4.5mm Sun Type 4 pad would work.

 

[sarawill]

This is the stuff I use: http://www.dltpodiatry.co.uk/Padding/polyfoam-5mm.htm

It's polyurethane so should last years and years.

c.f. https://onlinelibrary.wiley.com/doi/pdf/10.1002/jrs.4984

d.

Very interesting. Thanks!

Edit: What size are the sheets? It's looks pretty expensive from a quick search but I haven't seen any dimensions so far.

 

[sarawill]

My guess is they probably had problems with the shorter (than 4.5mm) pads and convinced themselves that the double-height pads were the answer when a 4.5mm Sun Type 4 pad would work.

I was thinking something along those lines as well.

 

[Al Kossow]

It's polyurethane so should last years and years.

Nope, polyurethane is not archival-safe, which is why I've been saying polyethylene
https://www.nps.gov/museum/publications/conserveogram/18-02.pdf

 

[drdanj]

Clearly they will degrade and have to be replaced (as did the originals), but it'll be at least another 20 years... I've not been able to spot a reasonable source of small quantities of PE foam of the right thickness. I do know, however, that the PU foam feels right. Most PE foam seems to be closed cell so far as I can tell.

 

[Chuck(G)]

I keep some extra rare drive belts purchased new in my freezer in a sealed bag against the day that I'll need them. Maybe that might work for extra foam pads as well.

 

[drdanj]

:D I like your thinking. I think the thing with these is, given an 11mm punch, 5mm foam and some aluminized mylar, you're not going to have any trouble making new ones, even 20 years down the line. The custom ICs on the keytronics keyboards are more of a long-term issue I'd have thought.

 

[Druid6900]

:D I like your thinking. I think the thing with these is, given an 11mm punch, 5mm foam and some aluminized mylar, you're not going to have any trouble making new ones, even 20 years down the line. The custom ICs on the keytronics keyboards are more of a long-term issue I'd have thought.

I have to agree with that. the XR 908 and the XR 950 chips, which make up the scan matrix (at least on the Model II Tandy keyboard) is something I have been looking for for the last 20 years, without success, I might add.

 

[sarawill]

I received my samples a day or so ago. I think I found the EXACT foam! It looks and feels the same as the original pads from my Compaq portable. Well, I say that but it is a bit more resilient since it hasn't aged. The samples were only available in 2" cubes so I have to order a sheet to make actual pads for testing. I just placed a small order to make some test pads. The pads will be 1/4" thick instead of 3/16", but I feel like the difference will not be an issue considering all the feedback I have received from all of you. I may or may not have also ordered a small polyethylene sheet as well. While it won't be as resilient the density was right so I thought, why not try it as well. I did it for Al Kossow. <3 I'll keep you posted on my progress. Thanks to everyone for all of your input, I appreciate it tremendously!

 

[falter]

I popped open the keyboard on my Hyperion and as someone suggested, it's another one of those capacitive type keyboards.



Most of the keys still work, but I thought I would test both of Sara's foam pad attempts to see if either worked. The light grey/blue disc batch did not work at all, but the silver disc batch actually seems to. Not great, but enough to render a couple of non functional keys functional again. They do alter the feel of the keypress (as was mentioned before, the foam is a little bit unforgiving. I think I'm just going to replace the foam on the keys that work for now and wait eagerly to see what Sara comes up with next. I really just needed to get my Enter key back more than anything.