SP PBT spacebars

[matt3o]

The other day I received Signature Plastics PBT spacebar samples. The good news is that they are all pretty thick.

I must say that quality is very good and they do not seem bent or deformed.

Bad news is that mounting points position is all screwed up. I doubt they would fit any keyboard as they are now. Stems are all few mm (or fraction of a mm) off from the standard position. I have to ask them how much would be to redo just the stems.

Anyway I believe this is a pretty good news nonetheless.

[BimboBB]

PBT spacebars are really nice. I use the one from Ducky nearly since one year every day and there is nearly no wear sofar. There is a bit wear of course, but not comparable with an ABS spacebar which usually has a big shiny area after half a year.

How does it come these stems are all wrong? By mistake or was it produced for a special keyboard/client?

[matt3o]

I have no clue what they was thinking when they made those mount points... maybe they have been produced for a client, I don't know.

[Muirium]

While we're asking about space bars, remember to mention small, Japanese style ones: I'd love some of that in my next PBT set. 6 units and greater is a waste of thumbs for many of us.

[Hypersphere]

I agree about small spacebars -- like the one on the Tex Beetle, for example.

In addition, there is a need for spacebars to fit the Leopold FC660 series, both the Cherry mx version (FC660M) and the Topre version (FC660C).

Can SP make Topre keycaps and spacebars? I tend to doubt it.

[matt3o]

Can SP make Topre keycaps and spacebars? I tend to doubt it.

they have some caps (ESC and wasd I think) but not enough to make a kb (and surely no spacebars)

[Findecanor]

I think the mount points being a few mm wrong is because they would have used moulds for ABS space bars to cast in PBT. The two types of plastic shrink differently. That is more noticeable when the key is as large as a space bar than with other keys.

I have the opposite at home that I could show you. Cherry PBT and ABS 6-unit space bars from the same type of moulds, both with the text "PBT" inside.

[Muirium]

Indeed, the "PBT" text shows up inside ABS caps frequently enough to put serious doubt on the claim that they use different moulds. Perhaps they should but they don't always actually do.

[Hypersphere]

They should be machined from an aluminum-magnesium alloy. Alternatively, what about 3D printing?

[Muirium]

CNC is so the future of custom keyboards. And maybe high end commercial ones too. Maybe…

[ne0phyte]

A SP PBT spacebar for Topre switches would be the greatest thing ever! I would gladly buy 10 or so since even though it's PBT, space is the most use key

[Hypersphere]

Space, the final frontier...

[dorkvader]

I like POM spacebars better, but the possibility of SP pbt spacebars is excellent!

ne0, I'm not convinced sp pbt spacebars for tope would be the best: they are rather sharp, and look odd when reversed. I wish SP would come out with a profile more well suited for flat keyboards.

[ne0phyte]

Well, they would have to match the Topre profile :p

[Muirium]

I've got a feeling that Topre mount caps (including HHKB and the Leopold) will have to come from our own machinery. Why? Because SP and the handful of other aftermarket manufacturers have had many years to respond to this but keep choosing no.

Perhaps their logic goes like this: they did well standardising on Cherry MX mount, it gives them enough volume to survive, and there are already high end caps on Topres anyway. I don't agree with this, but any deviation is a calculated risk. Whether to Topre mount, Alps/Matias, IBM, or other Cherries.

The cost of doing this ourselves, meanwhile, only ever comes down. In every material. Legends are probably going to be remain the tricky bit. Has anyone seen progress in dyesub? What's the preferred way to put durable legends onto metal? Questions like these could soon become more relevant.

[Hypersphere]

I've got a feeling that Topre mount caps (including HHKB and the Leopold) will have to come from our own machinery. Why? Because SP and the handful of other aftermarket manufacturers have had many years to respond to this but keep choosing no.

Perhaps their logic goes like this: they did well standardising on Cherry MX mount, it gives them enough volume to survive, and there are already high end caps on Topres anyway. I don't agree with this, but any deviation is a calculated risk. Whether to Topre mount, Alps/Matias, IBM, or other Cherries.

The cost of doing this ourselves, meanwhile, only ever comes down. In every material. Legends are probably going to be remain the tricky bit. Has anyone seen progress in dyesub? What's the preferred way to put durable legends onto metal? Questions like these could soon become more relevant.

I wonder if anodizing could be masked, so that, for example, a keycap made of aluminum could be anodized only in an unmasked area corresponding to a keycap legend? Then, legends could be printed in various anodized colors, which ought to be quite durable.

[matt3o]

yep you can mask anodization but the letters are really small, you would need some kind of CNC masking. it would be easier to engrave them

[Hypersphere]

yep you can mask anodization but the letters are really small, you would need some kind of CNC masking. it would be easier to engrave them

Good point. What about anodizing first and then engraving, so that there could be contrast between the anodized background and the exposed metal from engraving?

[matt3o]

could be done, sure.

[Hypersphere]

Excellent. No doubt it would be very expensive, but it ought to look awfully good.

On a somewhat different note, I was looking at my IBM SSK and its two-piece keys, with a separate stem and thin cap that fits over the stem. It would be great if all keys were like this, with completely interchangeable caps. I am now typing on my Leopold FC660C, and if I could change the appearance of the keys by simply popping on some thin outer caps, I wouldn't have to worry about different stems on Topres vs Cherries, etc.

[Muirium]

IBM caps are very smart. But don't forget about row profiles. Every cap on your SSK is interchangeable with every other one of the same size because of the curved backplate. The way that flat keyboards, like Cherry MX and Alps based ones, achieve the same smooth curve is to use distinctly shaped caps instead. If you go with all caps of the same profile, you get a very flat feel, like DSA. I like it, but not everyone does.

But I suppose what you're talking about is the ability to change a cap like-for-like. So swapping the Q key (row 2) from one key set with another Q key, and the 1 key above it (row 1) with another 1. You can't mix and match Dvorak, Bepo etc. from Qwerty that way, though. And then what's the advantage of two piece caps?

IBM likely did it out of necessity. Caps aren't just caps on buckling spring. They form part of the switch mechanism. Dividing duties makes sense as that way you can mass produce the "under caps" (I just invented this term, I don't know what they're really called) in greater numbers without care for legends. And then supporting various different national layouts is easier because of the interchangeability of the upper caps. We still benefit from all that on our IBMs today. Indeed, we can even convert between ISO and ANSI because every Model M membrane has contacts for them both and just needs the appropriate barrels to be used.

[Hypersphere]

IBM caps are very smart. But don't forget about row profiles. Every cap on your SSK is interchangeable with every other one of the same size because of the curved backplate. The way that flat keyboards, like Cherry MX and Alps based ones, achieve the same smooth curve is to use distinctly shaped caps instead. If you go with all caps of the same profile, you get a very flat feel, like DSA. I like it, but not everyone does.

But I suppose what you're talking about is the ability to change a cap like-for-like. So swapping the Q key (row 2) from one key set with another Q key, and the 1 key above it (row 1) with another 1. You can't mix and match Dvorak, Bepo etc. from Qwerty that way, though. And then what's the advantage of two piece caps?

IBM likely did it out of necessity. Caps aren't just caps on buckling spring. They form part of the switch mechanism. Dividing duties makes sense as that way you can mass produce the "under caps" (I just invented this term, I don't know what they're really called) in greater numbers without care for legends. And then supporting various different national layouts is easier because of the interchangeability of the upper caps. We still benefit from all that on our IBMs today. Indeed, we can even convert between ISO and ANSI because every Model M membrane has contacts for them both and just needs the appropriate barrels to be used.

Yes, thanks for reminding me about the IBM design. Love the curved plate and the fact that all the keycaps are of the same profile.

I just popped off one of the SSK's upper caps and compared it to a corresponding Cherry keycap from one of Feng's nice dyesub PBT sets. The IBM profile is much higher than that of the Cherry. Now that I look at the two keyboards, I realize that one thing I like about the look of the IBM keyboard is the high profile of the keys. The IBM profile is apparently more like the "OEM" profile of the stock keycaps on many standard keyboards, which many people seem not to like at all. However, I happen to like the little polymer towers.