O-Ring Mod on Different Kinds of PBT Caps?

[cgbuen]

I've been looking to buy PBT caps to outfit a new QFR. I've noticed that a lot of people can tell the differences between KBC Thin/SP/imsto thick, but how big are the differences between each kind when they have o-rings on?

I bring this up because I've been pretty big on o-rings (I notice that my speed/accuracy/comfort all increase), but some people have said they prefer imsto's due to the thickness. I'm wondering if a big part of this thickness preference might be curbed if o-rings stop the keys from bottoming out.

[dorkvader]

You will probably not notice the difference since you are not bottoming out.

I recommend PBT of any type, but you don't have to get super thick Cherry/Imsto PBT. I have a full set of SP PBT, and it's quite nice.

Also notice that some people prefer the feel of thinner keycaps.

I don't have much thick PBT (Yet). but I imagine the differences will be fairly slight.

[emptyk]

OP: I don't know about different PBT keys, but the o-rings work fine on my set of white PBT ninja keys. What I do know is that the o-rings do NOT work on my set of Red Alert doubleshots that SP made, which sucks. See this blog post for more details.

[dorkvader]

You can still get it to work with thicker o-rings or two o-rings, but you have a good point: The lack of stem stabilizers on SP keycaps means that O-rings are more complicated.

Actually, the lack of standardization makes it complicated, and SP's keycaps are a good example of this.

Is that your blog, emptyk? It is really nice.

[IvanIvanovich]

Some have also said they have problems with the thick o ring and Cherry profile thick keycap, it prevent actuation.

[emptyk]

Is that your blog, emptyk? It is really nice.

Yeah, thanks. My friend encouraged me to do it rather than emailing him whenever I got something "cool" to show him.

[WhiteFireDragon]

OP, I'm currently typing on imsto thick PBT caps with O-rings right now. Refer to the pic on the bottom. On standard thickness caps (ABS or PBT), I use O-ring size "E" because it purposely decreases the bottom-out distance so I can type a tad faster. In order to keep this same feel and bottom out distance, I'm using size "A" on the thick imsto caps right now. You're probably using size "A" right now on your standard caps, so if you want to retain this same feel, you'll need to find O-rings in size "D" because the stems on thick PBT caps are too short and will change the feel too much (bottom out distance) if you use the same O-ring size as your normal caps.

With O-rings installed, you can still feel the difference between material and thickness, but it's just that the noise is dampened and bottom-out distance is also shortened. I still have a pack of size "D" left so PM me if you're interested in those.

[TheProfosist]

OP, I'm currently typing on imsto thick PBT caps with O-rings right now. Refer to the pic on the bottom. On standard thickness caps (ABS or PBT), I use O-ring size "E" because it purposely decreases the bottom-out distance so I can type a tad faster. In order to keep this same feel and bottom out distance, I'm using size "A" on the thick imsto caps right now. You're probably using size "A" right now on your standard caps, so if you want to retain this same feel, you'll need to find O-rings in size "D" because the stems on thick PBT caps are too short and will change the feel too much (bottom out distance) if you use the same O-ring size as your normal caps.

With O-rings installed, you can still feel the difference between material and thickness, but it's just that the noise is dampened and bottom-out distance is also shortened. I still have a pack of size "D" left so PM me if you're interested in those.

Show Image

Nice chart bu I could never stand something like E on my caps

[cgbuen]

OP, I'm currently typing on imsto thick PBT caps with O-rings right now. Refer to the pic on the bottom. On standard thickness caps (ABS or PBT), I use O-ring size "E" because it purposely decreases the bottom-out distance so I can type a tad faster. In order to keep this same feel and bottom out distance, I'm using size "A" on the thick imsto caps right now. You're probably using size "A" right now on your standard caps, so if you want to retain this same feel, you'll need to find O-rings in size "D" because the stems on thick PBT caps are too short and will change the feel too much (bottom out distance) if you use the same O-ring size as your normal caps.

With O-rings installed, you can still feel the difference between material and thickness, but it's just that the noise is dampened and bottom-out distance is also shortened. I still have a pack of size "D" left so PM me if you're interested in those.

Show Image

Wow, thanks - that was extremely informative. Just to clarify, the o-ring difference you mention isn't dependent on the actual keycap thickness, but is due to the lower Cherry profile of the caps, correct? (So what you say applies to any Cherry profile caps, not just imsto thick)

Also, is there a conversion chart between the sizes of each of those o-rings in those letters to inches? I've been using these 008 ones from Amazon, which provided a nice big table of the o-ring measurement specifications for each product:

http://www.amazon.com/008-Buna-N-O-Ring-Durometer-Round/dp/B0052AU0HQ/ref=sr_1_1?ie=UTF8&qid=1347998514&sr=8-1&keywords=o-rings+buna+008

[IvanIvanovich]

Right, I think it's the E G that are too fat for Cherry profile. They don't leave enough room for the key to travel enough. The O ring stops it before actuate. Maybe if you keep crushing, but then it's like typing on a domes and who wants that feeling?

[WhiteFireDragon]

The O-rings in those pics are from a group buy I ran a long time ago. Here is the thread, the first post has all the size listed:

http://geekhack.org/index.php?topic=25714.0

[gbohn]

> What I do know is that the o-rings do NOT work on my set of Red Alert doubleshots that SP made, which sucks.

  I just updated a Leopold FC500R with Red Alert 2 DS keycaps and O-rings from WASDkeyboards.

  I initially put on their 40A-R (narrower style), but eventually noticed that the keycaps don't have a close enough 'backing' reinforcement or other backstop for the O-Rings.  So some of the keys (like the 1,2,3, etc. row) didn't seem to be damped.

  I ended up replacing the O-rings on the 'taller' stemmed keycaps with the thicker 40A-L style, and this seems to be working so far. (I left the thinner O-Rings on the Enter row since the stems are shorter here.).

  I was also more careful this time around to not push the O-Ring on the stem too far. As best as I can tell, these are still staying in place by the grip of the O-ring on the  stems (rather than being large enough to bump up against the keycap top.

  I'm not sure if these will move out of place over time thought...