A couple of 122-key IBM Model F's

[1391406]

One is going for $139 BIN + shipping. The other is going for $189.00 (or best offer) + shipping:

[berserkfan]

I strongly advise people to think carefully before they buy a monster such as this. It is very hard to work on.

[digi]

I strongly advise people to think carefully before they buy a monster such as this. It is very hard to work on.

my unsaver conversion tool

[1391406]

I strongly advise people to think carefully before they buy a monster such as this. It is very hard to work on.

I own two of them and they really don't need to be 'worked on' unless there's a problem or the owner wants to mod it in some way.

[dorkvader]

I strongly advise people to think carefully before they buy a monster such as this. It is very hard to work on.

I own two of them and they really don't need to be 'worked on' unless there's a problem or the owner wants to mod it in some way.

If the foam is is bad shape the owner would likely want to replace it.

I still have yet to get mine put back together after starting this foam replacement mod over a year ago.

[1391406]

I strongly advise people to think carefully before they buy a monster such as this. It is very hard to work on.

I own two of them and they really don't need to be 'worked on' unless there's a problem or the owner wants to mod it in some way.

If the foam is is bad shape the owner would likely want to replace it.

I still have yet to get mine put back together after starting this foam replacement mod over a year ago.

In my opinion, the only way you're going to know whether the foam is in bad shape is if you disassemble everything, but by doing that you're likely to facilitate damage that may require the foam to be replaced. Unless you're modding the board, I can't imagine why replacing the foam would be necessary assuming the board's functional and feels great. That's the case with my F-122's, despite the fact the foam in the one I disassembled is falling apart.

[sleepy916]

I strongly advise people to think carefully before they buy a monster such as this. It is very hard to work on.

I own two of them and they really don't need to be 'worked on' unless there's a problem or the owner wants to mod it in some way.

If the foam is is bad shape the owner would likely want to replace it.

I still have yet to get mine put back together after starting this foam replacement mod over a year ago.

LOL! It took me about a year to finally finish putting my 122 back together. It was more laziness on my part than anything. If you get the clamps, it's not bad. Good luck trying to use your hands though!  )

[fohat.digs]

I think that a big part of the problem is that people give up far too soon.

People have written me whining about "this is impossible, I tried 4 times and it did not work"

My experience is that if it works for me on the 4th try, I am delighted (and I know just what to do). Putting an F-122 back together would probably take a beginner a dozen tries, and I would recommend that you try not to get ruffled for at least that long.

And, after you finally succeed in reassembling it, do not be surprised if it has to come apart at least once to make minor changes or adjustments, and the counter starts over.

Some specimens are much harder than others, I grant you. Persevere, it will work.

[berserkfan]

I think that a big part of the problem is that people give up far too soon.

People have written me whining about "this is impossible, I tried 4 times and it did not work"

My experience is that if it works for me on the 4th try, I am delighted (and I know just what to do). Putting an F-122 back together would probably take a beginner a dozen tries, and I would recommend that you try not to get ruffled for at least that long.

And, after you finally succeed in reassembling it, do not be surprised if it has to come apart at least once to make minor changes or adjustments, and the counter starts over.

Some specimens are much harder than others, I grant you. Persevere, it will work.

Haha, hopefully you are not talking about me (since I tried more times than that on my F XTs.).

That said, I very much appreciate you weighing in on this. Very often a noob does not understand how many times we need to work on something to make it work. It's not laziness, but lack of confidence. If I try 3 times without a positive outcome, it is easy for me to think that I've done something wrong and need to do something else.

[dorkvader]

In my opinion, the only way you're going to know whether the foam is in bad shape is if you disassemble everything, but by doing that you're likely to facilitate damage that may require the foam to be replaced. Unless you're modding the board, I can't imagine why replacing the foam would be necessary assuming the board's functional and feels great. That's the case with my F-122's, despite the fact the foam in the one I disassembled is falling apart.

You can easily see the condition of the foam by just taking the top case off (on a 122 or "unsaver"). Also, if the foam is in good shape, opening it won't damage it further. It's easy to just leave it in place if you're swapping barrels or whatever around.

You may not have got a model F with foam in "really bad" shape. I have one and it's noticeable when compared with the NIB example I have.

Still, it's up to the person in question if bad foam is acceptable. I know some people here have used their model F with no foam at all.

LOL! It took me about a year to finally finish putting my 122 back together. It was more laziness on my part than anything. If you get the clamps, it's not bad. Good luck trying to use your hands though!  )

I have a clamp, but it's got a swivel. Disabling the swivel is gonna be tough, but I have high hopes for using a piece of metal or wood that attaches to the slide and will present a good solid "stop" for the edge of the KB to rest. The replacement foam I also have is a little on the "too thick" side. I hope to try again with thinner (and better) foam later.

I've reassembled all my other model F's several times, it's just the 122 with the "too thick" foam (and different bend radius in the middle) that's causing the biggest issue. I'm considering getting some metal bars that I can put in the middle and use C-clamps to bend the middle in a bit more so I can slide it together.

I strongly agree with perserverence! Most of us GH'ers are smart and get things quick, so it's really hard to continue after a few failures.

[1391406]

In my opinion, the only way you're going to know whether the foam is in bad shape is if you disassemble everything, but by doing that you're likely to facilitate damage that may require the foam to be replaced. Unless you're modding the board, I can't imagine why replacing the foam would be necessary assuming the board's functional and feels great. That's the case with my F-122's, despite the fact the foam in the one I disassembled is falling apart.

You can easily see the condition of the foam by just taking the top case off (on a 122 or "unsaver").

I had no idea the foam in my F-122 was anywhere near the shape it was in until I actually began separating the steel plates to get at the barrels and springs / pivot plates. It was only when I finally attempted to pull the plates apart that I saw the seriously fragile nature of the foam, which itself had to be gently and patiently separated from the plates lest it rip completely apart in multiple places. Had I not exercised the level of care I did, it could've easily been damaged to the point of being unusable.

Also, if the foam is in good shape, opening it won't damage it further.

I agree, but you can't tell what kind of shape it's in without disassembling it. The foam wasn't poking out the sides of the innards on mine, for example. Hence, it wasn't until I separated the plates that I discovered how bad the foam really was.

You may not have got a model F with foam in "really bad" shape. I have one and it's noticeable when compared with the NIB example I have.

No, it was bad. Granted, it didn't took look like Swiss cheese, but it was definitely falling apart to the point that I was a bit worried as to whether it would hold, although fortunately it did.

[fohat.digs]

Had I not exercised the level of care I did, it could've easily been damaged to the point of being unusable.

Disgustingly bad foam pads can still work.

I love the solidity and dampening that I get from the firm thick art foam, but, clearly, it causes a lot of grief.

Next time around I plan to get one of those clamps from Grand Harbor with non-swiveling heads!

[1391406]

Had I not exercised the level of care I did, it could've easily been damaged to the point of being unusable.

Disgustingly bad foam pads can still work.

I love the solidity and dampening that I get from the firm thick art foam, but, clearly, it causes a lot of grief.

I haven't noticed any difference in the way the board feels now vs. prior to my disassembling it, though I'm certain the foam was in better shape prior to the induced trauma. In my opinion, and this is just my opinion, unless the foam is unusable for some reason, replacing it seems unnecessary and more trouble than it's worth, but that's just me. I love the way both of my boards feel, crappy foam and all. If I saw real and practical benefit to replacing it, I might. I just don't see it. It seems like a lot of trouble for negligible benefit, in my opinion.

[dorkvader]

I was able to determine the condition of my foam as it's visible through the square holes in the front plate. If you poke at it and it crumbles and falls away then it's probably in bad shape: no disassembly required.

It's a bit harder to tell with beam springs as you have to take them apart to look at the foam. Fortunately for those KBs, replacing the foam and reassembling it is a lot easier, and a lot of people put up with wobbly barrels.

[1391406]

I was able to determine the condition of my foam as it's visible through the square holes in the front plate. If you poke at it and it crumbles and falls away then it's probably in bad shape: no disassembly required.

In my case, the foam at the square openings was intact and didn't really provide any indication of the internal damage, which was seemingly made worse by the inevitable shearing and tearing of foam during plate separation. The takeaway, for me anyway, is unless the owner is performing a mod or there's a problem, it's better to let sleeping dogs lie. While I think replacing the foam mat is a noble idea, as a lone goal it seems like an unnecessary pain in the ass, but that's me.

[vivalarevolución]

The Model F 122 foam replacement is not that difficult if you have the RIGHT TOOLS.  You need to have the right tools to make it go smoothly.  Don't be scared off.

[1391406]

The Model F 122 foam replacement is not that difficult if you have the RIGHT TOOLS.  You need to have the right tools to make it go smoothly.  Don't be scared off.

To me, and this is just me, it seems like a of a lot of work for very little benefit. The actual process of swapping the foam seems straightforward enough. It's finding the right materials and actually making the replacement that look onerous, and I guess I don't really see the big benefit.

[vivalarevolución]

The Model F 122 foam replacement is not that difficult if you have the RIGHT TOOLS.  You need to have the right tools to make it go smoothly.  Don't be scared off.

To me, and this is just me, it seems like a of a lot of work for very little benefit. The actual process of swapping the foam seems straightforward enough. It's finding the right materials and actually making the replacement that look onerous, and I guess I don't really see the big benefit.

Refurbishing an antique is always worth the trouble.  You saving the functionality of a great keyboard, and saving a piece of history.

[1391406]

The Model F 122 foam replacement is not that difficult if you have the RIGHT TOOLS.  You need to have the right tools to make it go smoothly.  Don't be scared off.

To me, and this is just me, it seems like a of a lot of work for very little benefit. The actual process of swapping the foam seems straightforward enough. It's finding the right materials and actually making the replacement that look onerous, and I guess I don't really see the big benefit.

Refurbishing an antique is always worth the trouble.  You saving the functionality of a great keyboard, and saving a piece of history.

I understand the desire to refurbish an antique. I'm curious how replacing the foam saves functionality if the keyboard already functions well, though?

[dorkvader]

The Model F 122 foam replacement is not that difficult if you have the RIGHT TOOLS.  You need to have the right tools to make it go smoothly.  Don't be scared off.

To me, and this is just me, it seems like a of a lot of work for very little benefit. The actual process of swapping the foam seems straightforward enough. It's finding the right materials and actually making the replacement that look onerous, and I guess I don't really see the big benefit.

Refurbishing an antique is always worth the trouble.  You saving the functionality of a great keyboard, and saving a piece of history.

I understand the desire to refurbish an antique. I'm curious how replacing the foam saves functionality if the keyboard already functions well, though?

You're right! Why bother cleaning the dirt off it: it doesn't affect functionality.

Why bother replacing the tops of missing two-piece keycaps. Legends are for noobs anyway. and it still functions.

Case cracked? don't even fix.

Wobbly barrels from bad foam? forget it!

Want to change the feel by replacing the foam with a better and longer lasting material, helping to ensure this KB lasts the next 70 years? Hey man : "If it ain't broke, don't fix it". I still see scancodes coming out of that thing, done even think about trying.

[vivalarevolución]

The Model F 122 foam replacement is not that difficult if you have the RIGHT TOOLS.  You need to have the right tools to make it go smoothly.  Don't be scared off.

To me, and this is just me, it seems like a of a lot of work for very little benefit. The actual process of swapping the foam seems straightforward enough. It's finding the right materials and actually making the replacement that look onerous, and I guess I don't really see the big benefit.

Refurbishing an antique is always worth the trouble.  You saving the functionality of a great keyboard, and saving a piece of history.

I understand the desire to refurbish an antique. I'm curious how replacing the foam saves functionality if the keyboard already functions well, though?

If the foam is in good shape, party on, I say.  My Kishsaver and one of my F 122s still have the original foam.

But if the foam is falling apart, the foam replacement is a good thing to do.  All of the foam on these will eventually fall apart in our lifetimes, unless somebody finds a Model F that was stored in a vacuum sealed, pitch dark chamber.

[1391406]

The Model F 122 foam replacement is not that difficult if you have the RIGHT TOOLS.  You need to have the right tools to make it go smoothly.  Don't be scared off.

To me, and this is just me, it seems like a of a lot of work for very little benefit. The actual process of swapping the foam seems straightforward enough. It's finding the right materials and actually making the replacement that look onerous, and I guess I don't really see the big benefit.

Refurbishing an antique is always worth the trouble.  You saving the functionality of a great keyboard, and saving a piece of history.

I understand the desire to refurbish an antique. I'm curious how replacing the foam saves functionality if the keyboard already functions well, though?

You're right! Why bother cleaning the dirt off it: it doesn't affect functionality.

Why bother replacing the tops of missing two-piece keycaps. Legends are for noobs anyway. and it still functions.

Case cracked? don't even fix.

You're comparing visible aesthetic defects to an internal flaw. It's akin to suggesting that if you're not going to clean the underside of your car, why bother washing it at all?

Wobbly barrels from bad foam? forget it!

If the foam is indeed causing the barrels to wobble to a notable degree, then of course, it goes without saying I'd want to change it. However, I just yanked a key from my modded F-122 (which I'm typing on) and wiggled the barrel. It doesn't wobble, and the amount of play is extremely negligible. Incidentally, all keys on Model M's and F's have a certain amount of play when the key caps are in place. Thus, I invite you to try and distinguish the difference in wiggle room between the keys on one of your Model M's and that of an F-122 with dilapidated foam. I just tried and can't tell a difference. With the key caps in place, the amount of play on both models is indistinguishable, at least on mine.

Want to change the feel by replacing the foam with a better and longer lasting material, helping to ensure this KB lasts the next 70 years? Hey man : "If it ain't broke, don't fix it". I still see scancodes coming out of that thing, done even think about trying.

If the difference in feel after replacing the foam were significant or substantial(ie. not negligible), I'd be all for it. However, in my limited experience, it seems like a non-issue. I'm not claiming it's never necessary, because I don't know. I'm just saying I think the benefits are likely negligible in most cases. However, whatever people choose to do with their keyboard(s) is their business.

[1391406]

if the foam is falling apart, the foam replacement is a good thing to do.  All of the foam on these will eventually fall apart in our lifetimes, unless somebody finds a Model F that was stored in a vacuum sealed, pitch dark chamber.

I think it's a very good idea. However, for me, I don't think it's worth the effort unless the effect of using dilapidated foam is noticeable. It may likely become noticeable at some point, although I figure I'll cross that bridge when I come to it.

[jacobolus]

If the difference in feel after replacing the foam were significant or substantial(ie. not negligible), I'd be all for it. However, in my limited experience, it seems like a non-issue. I'm not claiming it's never necessary, because I don't know. I'm just saying I think the benefits are likely negligible in most cases. However, whatever people choose to do with their keyboard(s) is their business.

The Model F keyboards I’ve seen had good-condition foam, but one of them was very dirty with a lot of dirt in the barrels making the feel pretty scratchy. I don’t think there’s a good way to thoroughly clean the barrels out without taking them out of the plate. At the point the whole keyboard is disassembled, if the foam isn’t in good condition it seems reasonable enough to replace it.

[1391406]

If the difference in feel after replacing the foam were significant or substantial(ie. not negligible), I'd be all for it. However, in my limited experience, it seems like a non-issue. I'm not claiming it's never necessary, because I don't know. I'm just saying I think the benefits are likely negligible in most cases. However, whatever people choose to do with their keyboard(s) is their business.

The Model F keyboards I’ve seen had good-condition foam, but one of them was very dirty with a lot of dirt in the barrels making the feel pretty scratchy. I don’t think there’s a good way to thoroughly clean the barrels out without taking them out of the plate.

Maybe a Q-tip dipped in alcohol or toothpick with a bit of tissue paper on the end.

At the point the whole keyboard is disassembled, if the foam isn’t in good condition it seems reasonable enough to replace it.

If the tools and materials needed to make the replacement were handy at the time of disassembly, why not give it a shot?

[jacobolus]

[...] one of them was very dirty with a lot of dirt in the barrels making the feel pretty scratchy. I don’t think there’s a good way to thoroughly clean the barrels out without taking them out of the plate.

Maybe a Q-tip dipped in alcohol or toothpick with a bit of tissue paper on the end.

Sounds like more trouble than just disassembling the keyboard and dunking all the barrels in detergent/denture cleaner for a few hours.

[1391406]

[...] one of them was very dirty with a lot of dirt in the barrels making the feel pretty scratchy. I don’t think there’s a good way to thoroughly clean the barrels out without taking them out of the plate.

Maybe a Q-tip dipped in alcohol or toothpick with a bit of tissue paper on the end.

Sounds like more trouble than just disassembling the keyboard and dunking all the barrels in detergent/denture cleaner for a few hours.

Dunking the barrels in detergent / denture cleaner is the easy part compared to the work involved in separating the steel plates, gathering and positioning all of the springs / pivot plates in the barrels, clamping / hammering the steel plates back together, and finally testing the board to ensure you didn't screw something up along the way. Personally, I'd opt for a Q-tip.

[fohat.digs]

If the difference in feel after replacing the foam were significant or substantial (ie. not negligible), I'd be all for it.

I think that my foam replacements have made a significant improvement in the feel of the keyboard. I did a few XTs and ATs with good-to-acceptable foam mats before I ever touched an F-122. These came apart and went back together by hand without undue heartache, although it was not exactly easy.

Of a dozen of so F-122s I have disassembled, only one had a mat that I would call "good" and perhaps 2-3 were "acceptable" if just barely. I suspect that the small ones had been stored in people's homes in decent conditions and the big boys had been stored in warehouses and other ugly industrial environments.

However, I consider raw Fs in the wild as being "too much" in terms of sound and vibration. A new thick firm mat dampens the vibrations from the center of the internal assembly, where dampening is most effective, and various other mats and padding, moving out from the center, become progressively less effective. I also consider the floss mod essential and have done every one of the Fs in my collection.

None of this is true with Model Ms, of course, because they are generally pretty "dead" to begin with.

As far as cleaning goes, when I take these things apart I use the opportunity to clean every single component as well as possible (I have even occasionally washed spring/hammer/pivot plates in soapy water (dish soap, not the alkaline stuff I use on plastic) although that is seldom necessary). I have never understood all that business about denture tablets when powdered laundry detergent and "oxi" works so well and so quickly. There is also sanding and painting involved as a matter of course.

Like I said before, of the dozen or so F-122s I have re-habbed, there were a couple that were particularly easy, and a couple that were particularly difficult, and one that was a complete nightmare. I do think that the long clamp from Grand Harbor with non-swiveling head will make a tremendous difference.

[1391406]

If the difference in feel after replacing the foam were significant or substantial (ie. not negligible), I'd be all for it.

I think that my foam replacements have made a significant improvement in the feel of the keyboard.

How so? In anecdotal comparisons in solidity of key feel between my Model M's and the F-122 I disassembled, there seemed to be no discernible difference in terms of movement of the barrels with key caps attached. While I can confirm the foam mat in my modded F-122 is sufficiently threadbare, perhaps it has yet to reach the threshold.

[fohat.digs]

How so?

anecdotal comparisons

It is very hard to articulate these things.

Having been through this exercise a couple of dozen times (on a variety of both Ms and Fs), I do believe that I have gained a feel for what happens. And, as I think many people agree, every buckling spring keyboard is different and has a personality of its own. But, some people have done bolt-mods on Model Ms and wondered why they could not tell any difference afterwards.

Dampening/isolation/etc is a tricky phenomenon to diagnose and remedy. A person who loves the feel and sound of a raw natural Model F might not want to change anything, anyway.

Personally, the stock F is too "wild" and noisy for my tastes, so "calming it down" a bit is just what I need to do. Compressing a nice thick firm sheet of shock-absorbing material in the innermost layer of the main assembly is a great place to start. Bedding the bases of the barrels (aka chimneys) is almost secondary to that. If you like springiness and noise, I might recommend a material like the very thin white latex that Unicomp uses for its modern Model M mats (aka blankets). That material actually helps to "liven up" the too-dead M, in my opinion.

But that is not what I want to accomplish when I am restoring a Model F, and my techniques have evolved to give me just what I want.

[vivalarevolución]

If the difference in feel after replacing the foam were significant or substantial (ie. not negligible), I'd be all for it.

I think that my foam replacements have made a significant improvement in the feel of the keyboard.

How so? In anecdotal comparisons in solidity of key feel between my Model M's and the F-122 I disassembled, there seemed to be no discernible difference in terms of movement of the barrels with key caps attached. While I can confirm the foam mat in my modded F-122 is sufficiently threadbare, perhaps it has yet to reach the threshold.

It's more a cosmic thing.  Once you get in more alignment with the galaxies, you'll understand the difference in feel.

[1391406]

How so?

anecdotal comparisons

It is very hard to articulate these things.

Having been through this exercise a couple of dozen times (on a variety of both Ms and Fs), I do believe that I have gained a feel for what happens. And, as I think many people agree, every buckling spring keyboard is different and has a personality of its own. But, some people have done bolt-mods on Model Ms and wondered why they could not tell any difference afterwards.

Dampening/isolation/etc is a tricky phenomenon to diagnose and remedy. A person who loves the feel and sound of a raw natural Model F might not want to change anything, anyway.

Personally, the stock F is too "wild" and noisy for my tastes, so "calming it down" a bit is just what I need to do. Compressing a nice thick firm sheet of shock-absorbing material in the innermost layer of the main assembly is a great place to start. Bedding the bases of the barrels (aka chimneys) is almost secondary to that. If you like springiness and noise, I might recommend a material like the very thin white latex that Unicomp uses for its modern Model M mats (aka blankets). That material actually helps to "liven up" the too-dead M, in my opinion.

But that is not what I want to accomplish when I am restoring a Model F, and my techniques have evolved to give me just what I want.

Personally, my focus is squarely centered on key feel rather than noise. I have relatively no interest in altering the sound, per se. Betwixt my two F-122's, the barrels on my unmodded board are quite solid, whereas the movement of the barrels on this modded F-122 is very, very negligible, though there's a trifling difference between them. However, in terms of feel, the only notable difference between them is that the unmodded board seems to have a slightly lighter actuation force. I fail to see how this could be related to the quality of the foam, however. I tend to attribute this to the slight variation in actuation force among Model M's and F's in general. None of the Model M's I've used feel or sound exactly alike, for instance. Faulty rivets could account for some of this variation, although I also tend to think it's likely that the springs age differently over time depending perhaps on how and where the keyboard is stored.

[1391406]

If the difference in feel after replacing the foam were significant or substantial (ie. not negligible), I'd be all for it.

I think that my foam replacements have made a significant improvement in the feel of the keyboard.

How so? In anecdotal comparisons in solidity of key feel between my Model M's and the F-122 I disassembled, there seemed to be no discernible difference in terms of movement of the barrels with key caps attached. While I can confirm the foam mat in my modded F-122 is sufficiently threadbare, perhaps it has yet to reach the threshold.

It's more a cosmic thing.  Once you get in more alignment with the galaxies, you'll understand the difference in feel.

Are you suggesting I'm not in alignment with the galaxies? I always check my tinfoil hat with a laser level. Maybe I'm doing it wrong.

[digi]

http://www.ebay.com/itm/IBM-1395660-Keyboard-IBM-FRU-1395661-Keyboard-for-AS400-/191296622146?pt=US_Vintage_Computing_Parts_Accessories&hash=item2c8a2ace42

[1391406]

Just out of curiosity, do the terminal (122-key) Model M's use a similar foam mat that could possibly be used as a replacement? There seem to be a ton of really good condition terminal M's out there for cheap.

[vivalarevolución]

Just out of curiosity, do the terminal (122-key) Model M's use a similar foam mat that could possibly be used as a replacement? There seem to be a ton of really good condition terminal M's out there for cheap.

No.  Those are going to have the rubber mat, per standard Model M design.  I think.

[fohat.digs]

Just out of curiosity, do the terminal (122-key) Model M's use a similar foam mat that could possibly be used as a replacement?

I was referring to the material itself, not the actual mat.

The new white latex Unicomp uses is much thinner and springier than the old black IBM rubber.

My guess is that these tough stretchy materials would be very hard to cut cleanly.

[1391406]

Just out of curiosity, do the terminal (122-key) Model M's use a similar foam mat that could possibly be used as a replacement?

I was referring to the material itself, not the actual mat.

The new white latex Unicomp uses is much thinner and springier than the old black IBM rubber.

My guess is that these tough stretchy materials would be very hard to cut cleanly.

So, to confirm, the white latex they're using now is a suitable replacement or too difficult to cut cleanly, as well? You'd mentioned it as a potential replacement earlier(although absent the dampening properties you prefer).

[fohat.digs]

white latex they're using now

I apologize for blending multiple trains of thought.

Assuming that you have worked on both Ms and Fs, you know that the M has a rubber mat (aka blanket) which I always assumed was mostly for electrical insulation. The old IBM mats were black. Today, the replacement Model M blankets from Unicomp are a very thin white latex, which is much tougher and stretchier but less padded than the old black ones. In my opinion, the new thin latex mats make Model Ms feel better and springier.

The Model F mat, which is completely different and serves another function altogether (mechanical not electrical), is much thicker soft foam with a "skin" layer on one side. I would guess that its original function was primarily intended as a bedding for the bottom plinths of the barrels (aka chimneys) to seat them into the pad and prevent them from moving in any direction.

As it ages it deteriorates, with the foam crumbling into a mass of gritty sticky mess, and the skin layer sticking itself to the plate surface.

When I settled on the art foam, I wanted to bed the barrels solidly, as well as dampen vibrations in both plates as they compress it. I learned ways to force the layers back together and button it all up tight, but many people seem to have trouble reproducing my results.

I am not the one to ask about alternative materials. I found what satisfies me.

All I can tell you is that the thinner the mat, the easier it will likely be to fit the plates back together. I would be interested to feel a Model F with a very thin but resilient mat. However, if you are interested in trying one of these thin tough materials, my guess is that it will prove difficult to cut properly.

[1391406]

All I can tell you is that the thinner the mat, the easier it will likely be to fit the plates back together. I would be interested to feel a Model F with a very thin but resilient mat. However, if you are interested in trying one of these thin tough materials, my guess is that it will prove difficult to cut properly.

Maybe an OLFA circle cutter? It can supposedly cut through cardboard and light wood.

[1391406]

The X-acto Precision Compass Cutter also looks like a potential candidate.

[fohat.digs]

Give it a try. I can't see those compass devices working on something that is tough and stretchy.

A good sharp punch still seems easiest.

[1391406]

Give it a try. I can't see those compass devices working on something that is tough and stretchy.

A good sharp punch still seems easiest.

Have you tried a leather punch on the latex mat? I would tend to think that would be the most effective option, though earliest comments left me with the impression it may be less than optimal.

I'm merely brainstorming ways to make a replacement with as little effort as possible. As far as actually trying it, maybe one day.

[dorkvader]

my leather punch (which was old and I spent some time with a file sharpening) over wood did a great job at cutting a hole in just about anything. I got a new one with the express purpose of using it to punch holes in material for model Fs.

Note, the unicomp blanket and old IBM mat are almost certainly too thin to be used to hold model F barrels. I suspect they protect the membrane from wear of the pivot plates (hammers).

1391406: here's my idea: get a rubber mat (or 10) and send it to a laser shop for cutting. Quick precise (cheap?). The hard part would be turning the laser on low enough to not damage it. I think it would be possible to make a DIY lasercutter and use it for mat cutting as well.

Another option is to talk to the guys at silhouette about their device and maybe do a couple of passes / layers of thinner material. I'm not sure they can cut 1/16 or whatever we want.

[1391406]

my leather punch (which was old and I spent some time with a file sharpening) over wood did a great job at cutting a hole in just about anything. I got a new one with the express purpose of using it to punch holes in material for model Fs.

Note, the unicomp blanket and old IBM mat are almost certainly too thin to be used to hold model F barrels. I suspect they protect the membrane from wear of the pivot plates (hammers).

1391406: here's my idea: get a rubber mat (or 10) and send it to a laser shop for cutting. Quick precise (cheap?). The hard part would be turning the laser on low enough to not damage it. I think it would be possible to make a DIY lasercutter and use it for mat cutting as well.

Another option is to talk to the guys at silhouette about their device and maybe do a couple of passes / layers of thinner material. I'm not sure they can cut 1/16 or whatever we want.

At this point, I suspect a good leather punch is likely the most cost effective and least time consuming option, and you're probably right that the Unicomp blanket isn't well suited to the task. With that in mind, it's likely I won't be replacing the foam in my F's any time soon unless a replacement becomes readily available(most unlikely!).

[dorkvader]

You will also need some scrap wood to use the punch over, and hope it doesn't dull too quickly.

I think once we get some easily-available material pre-cut then it will make restoring and refurbishing these a lot easier.

[fohat.digs]

it will make restoring and refurbishing these a lot easier.

Guys, I really want to apologize for the heartache that I might have caused many of you.

My process was a string of trial-and-error experiments until I settled on what I consider the best and most efficacious solution. It took about 4 keyboards being assembled and disassembled several times each, and a variety of tools and materials being tried.

I took pictures and built a guide that seemed pretty straightforward. It was not until the guide was already in place and in use that I encountered my first really difficult F-122 (Greek Stallion has it now) and realized that there might be times when somebody would embark on a restoration that would prove inordinately or unreasonably difficult.

The single most excellent recommendation that I have heard, and I have not gotten it myself, is the Grand Harbor bar clamp with non-pivoting head.

As more than one of us have said in the past, it is 1000 times easier with the right tools.

All that said, I still don't see a replacement mat as the "make or break" component for completing this project in a reasonably simple fashion.

[1391406]

Guys, I really want to apologize for the heartache that I might have caused many of you.

Quite the contrary. Without your guide, there'd be quite a bit more heartache, I'm sure.

I still don't see a replacement mat as the "make or break" component for completing this project in a reasonably simple fashion.

But it's one less headache to deal with.

[nubbinator]

They added one at $129.99

http://www.ebay.com/itm/Very-Rare-IBM-6110347-Model-F-122-Key-Keyboard-Clicky-May-85-Vintage-/141384106358?pt=PCA_Mice_Trackballs&hash=item20eb264176

[1391406]

I bought one from this seller earlier in the week. No shipping info. yet, though.