PBT Keycaps Cracked Stems

Hey all,

Was switching the PBT Keycaps from my previous board to the Platinum when I noticed that the keycaps have cracks on the stems (see attached photo). There is one of these cracks on every corner of every stem, some more faint than others.

Also, there were 5 keycaps (now 2) that are "unstable". Unstable in the sense that if you pushed them off centre they will lean in the direction you pressed them, extremely irritating and unacceptable especially when it has occured on the least used keys on the board.

I managed to improve some of the keycaps by heating the stem up with a hairdryer for a minute and then pinching the top end of the stem together. This worked on most of the keys, namely ESC, F1 and F3 while RIGHT CONTROL and PRINT SCREEN remain "unstable".

I was thinking that while PBT has a significantly stronger grip than ABS that the cracks are causing some of the keycaps to behave this way, since an ABS keycap, cracked the same way, always bounces back into the upright position when pressed off centre. But this is only speculation as I do not know what is causing this.

And no, I don't have a habit of taking the keycaps off and on again.

Corsair should give you a replacement ASAP. Did you buy the keycaps separately or did they come with your keyboard?

In my case, I just plunked down on a set of replacement PBT keycaps. They shouldn't split in general, but I'd say the bigger culprit is the + used by the Cherry switches. The newer low profile switches have a ring surrounding the + so the key cap stem is supported around the outside, where the bulk of the force on the stem can't do any damage.

My best advice if you haven't gone low profile is to use those silicone dampeners since they do grip the stem somewhat and be gentle on your keyboard. Ultimately though, splitting key cap stems are a result of a flawed original Cherry switch design.

The downside to Cherry's low profile switches is that you cannot (easily) use those silicone rings to damped the clack when keys bottom out. You would have to fit them to the ring on the switch instead of on the key cap stem. The issue is this ring by design is meant to sit flush with the switch housing when fully pressed, so trying to reseat a key cap without your dampener coming off is tricky. There's also a risk of getting it sandwiched between the + and the top of the stem when you force a key cap back on.

Corsair seriously needs to upgrade their full keyboard lineup to low profile switches and offer low profile PBT key caps to existing owners.

At the same time, Cherry needs to get up off their backsides and make more low profile color options besides just red and silver.

Corsair should give you a replacement ASAP. Did you buy the keycaps separately or did they come with your keyboard?

 

In my case, I just plunked down on a set of replacement PBT keycaps. They shouldn't split in general, but I'd say the bigger culprit is the + used by the Cherry switches. The newer low profile switches have a ring surrounding the + so the key cap stem is supported around the outside, where the bulk of the force on the stem can't do any damage.

 

My best advice if you haven't gone low profile is to use those silicone dampeners since they do grip the stem somewhat and be gentle on your keyboard. Ultimately though, splitting key cap stems are a result of a flawed original Cherry switch design.

 

The downside to Cherry's low profile switches is that you cannot (easily) use those silicone rings to damped the clack when keys bottom out. You would have to fit them to the ring on the switch instead of on the key cap stem. The issue is this ring by design is meant to sit flush with the switch housing when fully pressed, so trying to reseat a key cap without your dampener coming off is tricky. There's also a risk of getting it sandwiched between the + and the top of the stem when you force a key cap back on.

 

Corsair seriously needs to upgrade their full keyboard lineup to low profile switches and offer low profile PBT key caps to existing owners.

 

At the same time, Cherry needs to get up off their backsides and make more low profile color options besides just red and silver.

Yeah, I did send a support ticket to Corsair, although this is happening on both sets including this one, so probably just a bad batch.

As for the rubber dampeners, I don't use them as they make red/silver switches very mushy.

Edit: Bought the keycaps separately.

The tolerances are pretty tight so a bad batch is possible.

I managed to set mine up just yesterday. I have the gunmetal model with a mix of both black and white PBT key caps. I think the look is spectacular.

As for the silicone rings, I've found that adding only one has no impact since the stem doesn't go down all the way when the keys are pressed. Adding two dampeners seems to be the spot where you can feel and hear a difference. I have it set up this way on all the letters and space bar.

Adding three of them has the best effect and totally mutes the noise and tightens up the feel of the travel. I have it done that way on the cursor keys and white numpad keys as shown in the image here. Even with the three silicone rings in place they don't affect the lighting since I specifically ordered transparent ones.

The use of the rings hasn't affected my gaming, probably because I'm using a harder silicone. They don't feel mushy all and still firm, but with three of them fitted they are definitely quieter and feel tighter.

I particularly like the textured feel of the PBT key caps versus the smoothness of the normal ones. The glossy ones caught fingerprints far too easily and looked just ugly after a quick test type.

I'm also happy with the enter key on this unit and none of the larger keys are showing any signs of wobble - the K95 I bought earlier had an enter key that operated like a see saw.

This was an expensive purchase so my expectations have to be high. It also took me quite some time to install the dampeners and swap key caps. Customizable keyboards are still a niche item. I am happy with the end result so far, but time will ultimately tell who good Corsairs quality and reliability really is.

The tolerances are pretty tight so a bad batch is possible.

 

I managed to set mine up just yesterday. I have the gunmetal model with a mix of both black and white PBT key caps. I think the look is spectacular.

 

As for the silicone rings, I've found that adding only one has no impact since the stem doesn't go down all the way when the keys are pressed. Adding two dampeners seems to be the spot where you can feel and hear a difference. I have it set up this way on all the letters and space bar.

 

Adding three of them has the best effect and totally mutes the noise and tightens up the feel of the travel. I have it done that way on the cursor keys and white numpad keys as shown in the image here. Even with the three silicone rings in place they don't affect the lighting since I specifically ordered transparent ones.

 

The use of the rings hasn't affected my gaming, probably because I'm using a harder silicone. They don't feel mushy all and still firm, but with three of them fitted they are definitely quieter and feel tighter.

 

I particularly like the textured feel of the PBT key caps versus the smoothness of the normal ones. The glossy ones caught fingerprints far too easily and looked just ugly after a quick test type.

 

I'm also happy with the enter key on this unit and none of the larger keys are showing any signs of wobble - the K95 I bought earlier had an enter key that operated like a see saw.

 

This was an expensive purchase so my expectations have to be high. It also took me quite some time to install the dampeners and swap key caps. Customizable keyboards are still a niche item. I am happy with the end result so far, but time will ultimately tell who good Corsairs quality and reliability really is.

So your keycaps don't have any cracks anywhere? Just want to know if this is intentional to let the PBT stretch over the stem or something as some of the cracks look organic while others are straight down.

As for the O-rings, I never tried them. I like my boards relatively loud so I never thought of buying them. I also heard people complaining that they made the keyboard too mushy, especially on red/silver switches, so that was another turnoff.

I had 18 keys fail exactly in this manner on my k70 eventually corsair sent me some replacements

What's funny, all of the ABS keycaps that came stock with my K95 Platinum where broken as well, apart from the macro keys. I immediately swapped them out for favour of these PBT keycaps, so I never installed or used them.

This isn't the case on a family member's Strafe RGB or my previous K95 (non-platinum) where the ABS stems do not have any imperfections.

So your keycaps don't have any cracks anywhere? Just want to know if this is intentional to let the PBT stretch over the stem or something as some of the cracks look organic while others are straight down.

 

As for the O-rings, I never tried them. I like my boards relatively loud so I never thought of buying them. I also heard people complaining that they made the keyboard too mushy, especially on red/silver switches, so that was another turnoff.

Mine's brand new and I checked every single one as I was fitting the rings on - no cracks anywhere.

Of course, that may not be the case after 6 months use. Corsair's warranty on the PBT key caps is 2 years, yet if you read the fine print they specifically exclude "wear and tear associated with normal use". I am gentle on my keyboard so I will consider that "normal use". If key cap breakages are this common (and it does appear so) then it comes down to two possible scenarios - a manufacturing defect or a fundamental design flaw (or a combination of both).

One thing I WOULDN'T advise is removing key caps on a regular basis. If you need to clean your keyboard remove them just once a year and clean your work area daily/weekly. Given the tolerances on the stem and force needed to pull/push keys on/off it's definitely possible to have them split prematurely. Neither ABS or PBT is particularly strong when it gets thin, and like many plastics, repeated force will eventually result in material fatigue.

The low profile switches are more forgiving - you can pull/push key caps more confidently on those because the support ring centers the stem on the + so it doesn't stab on at an angle or (worse) rip off at an angle either.

As for the rings, I can definitely recommend them. I have the silver switches and they are still working the same, no mushiness or delay. They aren't completely quiet since you still hear the racket as the switch returns to the top, but on the down press they can be almost muted.

It also depends on how hard/fast you type. Even with two dampeners fitted per key I can still make plenty of noise punching out articles etc... so it's impossible to get an experience like you would typing on a non-mechanical keyboard even with o-rings installed.

Mine's brand new and I checked every single one as I was fitting the rings on - no cracks anywhere.

 

Of course, that may not be the case after 6 months use. Corsair's warranty on the PBT key caps is 2 years, yet if you read the fine print they specifically exclude "wear and tear associated with normal use". I am gentle on my keyboard so I will consider that "normal use". If key cap breakages are this common (and it does appear so) then it comes down to two possible scenarios - a manufacturing defect or a fundamental design flaw (or a combination of both).

 

One thing I WOULDN'T advise is removing key caps on a regular basis. If you need to clean your keyboard remove them just once a year and clean your work area daily/weekly. Given the tolerances on the stem and force needed to pull/push keys on/off it's definitely possible to have them split prematurely. Neither ABS or PBT is particularly strong when it gets thin, and like many plastics, repeated force will eventually result in material fatigue.

 

The low profile switches are more forgiving - you can pull/push key caps more confidently on those because the support ring centers the stem on the + so it doesn't stab on at an angle or (worse) rip off at an angle either.

 

As for the rings, I can definitely recommend them. I have the silver switches and they are still working the same, no mushiness or delay. They aren't completely quiet since you still hear the racket as the switch returns to the top, but on the down press they can be almost muted.

 

It also depends on how hard/fast you type. Even with two dampeners fitted per key I can still make plenty of noise punching out articles etc... so it's impossible to get an experience like you would typing on a non-mechanical keyboard even with o-rings installed.

I'm not a heavy typer, nor do I repeatedly take off and put on the keycaps, I've only taken the keycaps off once, and that was when swapping keyboards. Even when I did swap them out I never installed/removed them at an angle, always straight up/down. So I highly doubt it is fatigue.

Also, when searching for the cracking issue with other pbt keycaps, I cannot find anything on them splitting or the like.

As for the O-rings, maybe they're worth a shot. I'll just make sure I get the dense ones and not the soft, squishy kind.