How do I know if I found PBT keycaps for my Topre realforce?

[huttala]

Hi guys!

I just found out that the keycaps from an old keyboard that I found fits my Topre realforce just fine, but I'd love to know if they are PBT or not, how do I find this out?

Havn't found any information about the keyboard that I found, but the caps feel great, but I can't tell if they are PBT or ABS.
Some help would be awesome, and just to be nice I'll put up a picture of the raelforce with the caps aswell. I think it looks awesome.
I'm not done with the swap just yet, but I'm going to switch the arrow keys and the other above them aswell, and leave all the modifiers(enter, shift caps etc) black.



EDIT:
And oh! I have to take some pics of the old keyboard that I took all the caps from. Here you go.



And yes, that's bird shit on the keyboard, found it outdoors at work.

[002]

What the heck...
Could you take a screenshot of the underside of the keycap for me please?

[huttala]

Sure thing!
They don't fit aswell as the regular topre, but they are in place and they don't wobble.
And they don't look like they should fit, but they fit just fine, that saved me from 110$ caps from EK


Still want to know if they are PBT or not tho, they feel amazing anyway, like em much better then the standard caps.
They are thick as hell anyway.

[rodtang]

You could do the acetone test, do not do this on any caps you might want to keep though.

[002]

I'd also like to register my interest in getting some of these if you have any more or plan to part with them.

[huttala]

I know I can do the acetone test, but as you say, it might ruin one of the caps and I don't want to do that.

002: I don't have anymore of these caps, and I want them to my realforce keyboard, so I'm not selling them. I do however have caps for a dell quiet key, and they seem to fit just as good as these caps, they are not as thick as these caps tho.

I'll just take some pics instead, so you can see.
From the left to the right: Digital, Quiet key, Topre.


EDIT:
Just finished up with the keycap cleaning, I think this looks amazing. What do you guys think?
Maybe I should put this in the picture section aswell.. hrmmm..

[002]

I take it that seeing as the cut/groove in the stem is going in horizontally as opposed to the Topre which goes in vertically that they do not click into place when you push them on?

[guilleguillaume]

What the hell is going on here

Nice find.

[huttala]

I take it that seeing as the cut/groove in the stem is going in horizontally as opposed to the Topre which goes in vertically that they do not click into place when you push them on?

Actually they do, thats the strange thing. But I guess its because they are just a tad wider then the "groves" in the housing on the topre switch, dunno how to express myself in english but I hope you understand, they do however click in place just fine, and as I said before, they don't wobble. The only thing I noticed is that the keycap does bottom out so the keycap hits the bottom of the keyboard, so it kinda sounds like I'm using a cherry brown keyboard now, when I bottom out that is.

But let's not drift off too far now, I still want to know what kind of keyboard I took these caps from and what kind of caps it has.

Anyway, I'm really happy with this find.

[Autolyze]

Wow, that's pretty impressive. Do the keycaps still feel nicely textured? I think old ABS keys would almost certainly be kind of slick by now unless the keyboard had just been sitting in the closet for most of its life.

[huttala]

Wow, that's pretty impressive. Do the keycaps still feel nicely textured? I think old ABS keys would almost certainly be kind of slick by now unless the keyboard had just been sitting in the closet for most of its life.

They do, there's no shine at all.
My camera wouldn't focus closer then this.

[ripster]

You do the acetone test with a Red Sable artist brush, acetone, and the UNDERSIDE of the key on one of inner walls.

PieceOcake.

[huttala]

You do the acetone test with a Red Sable artist brush, acetone, and the UNDERSIDE of the key on one of inner walls.

PieceOcake.

But if it's ABS it will ruin the keycap, right?

[002]

No - you only need to apply a small amount. It won't go through the whole keycap or anything.
Do it on a key that it's compatible like Caps Lock or something?

[huttala]

The only cap that doesn't fit is the spacebar, so I guess I'll try on that one then. Just have to get some acetone from somewhere.

[Icarium]

Keyboards with spacebars made of different plastic exist.

[hasu]

There is non-destructive test.
You can just put your caps into saturated salt water and see whether they sink or not.
PBT caps will sink and ABS not.

[mintberryminuscrunch]

wait for it...

[huttala]

There is non-destructive test.
You can just put your caps into saturated salt water and see whether they sink or not.
PBT caps will sink and ABS not.

Aight, I'll try that when I come home from work.
they did however sink in regular water when I cleaned them.

[Tycn]

Oh fuck me.

Got a bunch of these boards in a haul a while ago. Sliders over domes. Went straight to the e-waste.

They were lasered ABS IIRC. Not terrible but not good either.

I wouldn't have used them but would have happily distributed them to anyone interested.

[ripster]

There is non-destructive test.
You can just put your caps into saturated salt water and see whether they sink or not.
PBT caps will sink and ABS not.

Or break them with hammers. PBT shatters. ABS gets dented.

Plus this method is loads of fun.

[Mrinterface]

How to tell the difference between POM, ABS and PBT then ?

[yench]

maybe they taste differently...

[huttala]

There is non-destructive test.
You can just put your caps into saturated salt water and see whether they sink or not.
PBT caps will sink and ABS not.

I did this, and the Topre keycap sunk like a stone.
The ones that I found did not, so it's ABS... What a shame, but I'm happy anyway since they feel great to type on, guess they fit well with the ABS spacebar on my topreboard... Right ripster?

Oh, and for those that thinks that the keys dont pop in place I took a picture with the keyboard upside down, I can shake it aswell, but thats kinda hard to get om a picture.

[dirge]

http://www.ebay.co.uk/itm/DIGITAL-KEYBO ... 1c254b72d1

Is that another one?

[huttala]

http://www.ebay.co.uk/itm/DIGITAL-KEYBO ... 1c254b72d1

Is that another one?

Doesn't look like it since that board doesn't have the grey modifiers like mine has.

But as I said before, they keys from a Dell quiet key does fit just as well as the caps from a digital board.
I have one Dell quiet key that just lies around, so if anyone wants the caps from it feel free to give me a price your willing to pay, the board just lies around and doesn't get used anyway.

[Julle]

http://www.ebay.co.uk/itm/DIGITAL-KEYBO ... 1c254b72d1

Is that another one?

That looks like a rubber dome Digital keyboard I used to have, save for the colour of the PS/2 plug. I think these came with Digital workstations in the mid-90's.