Unicomp v IBM spring/hammers difference

[o2dazone]

There's a theory that the age of springs and hammers have an influence on the key feel of a Model M. I did a rebuild of an SSK a while back. Bolt mod, a good cleanup, the whole nine. While the board was splayed open, I decided to get fresh new springs/hammers from Unicomp. I've always heard they were 5g less force, but I also heard that translated into them being just ever so slightly lighter (and hardly noticeable).

I don't use a Model M as a daily driver (in fact I hardly use one at all), but it was definitely noticeable for me. It was much more subdued. My original post stated that it was because Unicomp has actually manufactured lighter springs to compensate for the design changes they made from the original Model M to the Unicomp. But others suggest (and it makes sense), that the feeling of an original Model M, with old/worn parts are to blame from what a new Model M, aka Unicomp parts would feel like.

So I tore down a nice Model M(with only 2 missing rivets, blow me) for the springs and hammers. I put them in the SSK, and the feeling was back to what I was familiar with it. An assumption would be the 5g in difference mostly comes from age of springs, versus brand new springs, which are a lot more flexible.

TL;DR if you're restoring an M, and want to preserve the original keyfeel (that might have atrophied from age), make sure you do it with original model m parts. Unicomp springs/hammers could influence the feeling, and might not be what you would expect when typing on an older Model M that's been through the elements.

Oh, and the two rivets that were missing were glued over the top. I've heard of that method to fixing broken rivets but never saw it in real life. It didn't stop my sharpened spackle knife, but found it to be interesting.

[weenis]

I disagree with this post...

So for anyone looking for information on this issue, just know it is disputed, don't take o2dazone's post as rule or law.

I bolt molded a IBM M with brand new springs from Unicomp, and sitting next to a very low mileage IBM M, they feel very close. If I were to say one felt better than the other, it would be the one with the Unicomp springs, but I think it's the keys, not the springs. The keys on the board with new springs are 1 piece instead of 2 piece.

Typing this post on the IBM M with Unicomp springs, there is very tactile spring action, nice click confirmation, and pretty ideal for a Model M.

[486]

I don't know how they can be different. Unicomp uses the same design and equipment used to produce the springs that IBM did. Maybe it is because the Unicomp springs are fresh or youre ibm springs were very worn

[mkawa]

metal fatigue and deformation can do a heck of a lot to a spring over the years, and frankly the variance and tolerances on keyboard springs are going to be pretty large right out of the gate as it is

unicomp/lexmark M/IBM has also changed the elastic blanket material that sits over the membrane. this material has a lot to do with key feel, and ages much more quickly than the springs.

[tp4tissue]

metal fatigue and deformation can do a heck of a lot to a spring over the years, and frankly the variance and tolerances on keyboard springs are going to be pretty large right out of the gate as it is

unicomp/lexmark M/IBM has also changed the elastic blanket material that sits over the membrane. this material has a lot to do with key feel, and ages much more quickly than the springs.

Ok, let's just do a swap of that membrane, and we'll have "TRUTH"

Unless the OP decides to lie about it to save face on the interwebz?

Is that membrane now, softer, or harder

[ch_123]

The most pleasant Model M I've typed on is a bolt-modded SSK with new Unicomp springs.

Age, and slightly different manufacturing tolerances over the years will account for some differences, but the difference should be relatively small...

[o2dazone]

I bolt molded a IBM M with brand new springs from Unicomp, and sitting next to a very low mileage IBM M, they feel very close.

Hey weenis,

Thanks for posting your findings. That's rather interesting. If your low mileage Model M feels a lot like a bolt modded M with Unicomp springs and hammers, then maybe it's just a difference in age. Perhaps my brain and fingers prefer the old clunky loud Model M key feel, while new Model M's don't really have that same feeling. That could be the only thing I could assume.

I'll reword my original post to sound less judgmental of unicomp springs and hammers. I'll agree that it's a matter of preference. If someone is doing a rebuild, and is concerned about preserving the feeling of your existing Model M, and you want to bolt mod, be weary about replacing those springs and hammers with new ones. It could potentially change what your fingers/muscles have become adjusted to, and it might produce a feeling you're not used to, or not expecting.

As for two piece or one piece, I'm not sure that makes a difference. I have original one piece, original two piece, and Unicomp two piece. They all seem to feel/snap exactly the same. In fact, due to my shortage on a few keys, I have a few one pieces mixed in on a two piece board, and it's indistinguishable while typing.

When I disected the Model M for its parts, I cut the number pad off of the rubber sheet and used that one in my SSK because it was in better condition (the ssk I received was pretty beat), so it's very possible it could be that as well.

[o2dazone]

Unless the OP decides to lie about it to save face on the interwebz?

I'm not sure I give enough ****s about my face on GH to lie about something like this

[rknize]

I recently replaced the blanket on an SSK with a Unicomp one.  It kept all of the original springs and hammers.  It was already bolt-modded, but the blanket was deformed and some of the keys were acting wonky.  The keyboard is quite different with the thinner, stretchier Unicomp mat.  It's more snappy and sharper feeling...a bit more Model F-like, if you will.  I like that it's different, actually, but I have a lot of Model Ms.

[mkawa]

just fyi, i've directly compared the old-style black rubber blankets to unicomp's new thinner white blankets (which i think have more latex in them), and i vastly prefer the new blankets. maybe rknize can chime in, as he did this to his ssk recently too.

[fohat.digs]

Wallet hack gets you from all angles.

I have never taken a Unicomp apart, and all my bolt-mods have the old black rubber.

How much does Unicomp charge for the new white ones?

[rknize]

$10

[o2dazone]

I recently replaced the blanket on an SSK with a Unicomp one.  It kept all of the original springs and hammers.  It was already bolt-modded, but the blanket was deformed and some of the keys were acting wonky.  The keyboard is quite different with the thinner, stretchier Unicomp mat.  It's more snappy and sharper feeling...a bit more Model F-like, if you will.  I like that it's different, actually, but I have a lot of Model Ms.

Wow, I had not considered the blanket. Not applicable in my case persay (I went from one old blanket to another), but I wonder why the change. Perhaps just more resistance to age?