Author Topic: Advice on Grinding My Keycaps (Interference)?  (Read 2225 times)

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Offline theosuxxx

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Advice on Grinding My Keycaps (Interference)?
« on: Tue, 02 November 2021, 05:52:37 »
I'm putting the finishing touches on my Filco MJ2 TKL and I've reached the final hurdle, but it's a big one.

The keycaps I am putting on this board are the grey PBT set from KPRepublic. They are Cherry profile, and quite thick. Upon putting them on my board, I noticed two things:
  • All of the stabilized keys are extremely mushy and do not bottom out properly. Some of them also tick very loudly when pressed.
  • Two of the bottom row keys (LWIN and LALT) do not feel or sound like they are bottoming out properly.

Upon closer examination, I found that the wire of the Costar stabilizers interfere with the keycaps on the stabilized keys, and the two mushy keys on the bottom row were on north-facing switches, the only ones on the whole board oriented that way. The keycaps being Cherry profile probably exacerbate the degree of interference.

I have attempted to use O-rings, but they don't help much at all. It pains me, but at this point, I think my best option might be to take an emery board and shave off the front inner edge of the problem keycaps to eliminate the interference. I have read a few threads mentioning this solution, and it seems to be effective.

Can anyone with experience regarding this issue offer some advice on how I can best approach this process? These keycaps aren't incredibly valuable, but I would like to do a neat job and avoid ruining anything. I was thinking to tape the emery board off so it doesn't grind too far into the keycap, but I have no clue if this would work. I would also be very grateful for any alternative solutions.

Offline Riverman

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Re: Advice on Grinding My Keycaps (Interference)?
« Reply #1 on: Tue, 09 November 2021, 18:04:20 »
I use a carbide carving bit on a Dremel, like their model 9901.  It's surprising how hard PBT keycaps are, and how much back and forth is needed to grind down an appreciable amount, but in my experience, it doesn't take much to reduce the interference.  I had to Dremel a lot of PMK SA keycaps for a Topre RGB a while back.  They'd click on the downstroke because they were so thick they'd tap the side of the switch housing.


Offline theosuxxx

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Re: Advice on Grinding My Keycaps (Interference)?
« Reply #2 on: Wed, 10 November 2021, 04:11:39 »
Just did my spacebar today, and I'm glad to report that the modification seems to be working. I held the keycap vertically with the front side down on the edge of a book and went back and forth with the tool in my other hand. I can now bottom out the spacebar properly. :thumb: I thinned about 2cm of the inner front face in the center of the spacebar (where the wire has a bend) and two small 1cm sections in front of each stabilizer insert post, all cuts about 5mm up from the bottom of the keycap. An interesting observation: at least for me, grinding the spots in front of the stabilizer inserts (ie the left and right posts) made much more of an improvement than grinding in the center, which I did not expect. Not sure if this will be the case with the other stabilized keys; will try to experiment and report back later.

I use a carbide carving bit on a Dremel, like their model 9901.  It's surprising how hard PBT keycaps are, and how much back and forth is needed to grind down an appreciable amount, but in my experience, it doesn't take much to reduce the interference.  I had to Dremel a lot of PMK SA keycaps for a Topre RGB a while back.  They'd click on the downstroke because they were so thick they'd tap the side of the switch housing.

I'm currently just using the bits that came with my rotary tool, so I've been carving out the bulk of the material with a metal engraving bit and smoothing it over with a cylindrical stone bit. Also, I totally agree; the PBT takes a ton of time to remove, and my hand gets shaky so I have to take breaks often. Do you have any advice on keeping the cuts neat and consistent? A jig seems excessive for five keycaps, but I also don't want to make a total hack job out of it.

Offline theosuxxx

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Re: Advice on Grinding My Keycaps (Interference)?
« Reply #3 on: Sun, 14 November 2021, 23:25:05 »
Updating for conclusion. The fix worked and my board is complete, although the job was not very clean. I have another order of thick keycaps coming in, and in the future I would like to test whether north-facing keyswitch washers would fix this issue without the need to grind.

Offline Riverman

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Re: Advice on Grinding My Keycaps (Interference)?
« Reply #4 on: Thu, 18 November 2021, 00:49:06 »
I'm currently just using the bits that came with my rotary tool, so I've been carving out the bulk of the material with a metal engraving bit and smoothing it over with a cylindrical stone bit. Also, I totally agree; the PBT takes a ton of time to remove, and my hand gets shaky so I have to take breaks often. Do you have any advice on keeping the cuts neat and consistent? A jig seems excessive for five keycaps, but I also don't want to make a total hack job out of it.
I'll be the first to admit that my grinding job isn't the neatest.  At first, it bothered me, especially because I was grinding a set of $100+ SA keycaps, but after a while, I decided that no one's going to look at the inside of them, so I decided not to worry about it too much.

Offline stidal

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Re: Advice on Grinding My Keycaps (Interference)?
« Reply #5 on: Thu, 18 November 2021, 04:39:02 »
fwiw, olkb has washers that fit around the stems and raise the keycap enough to avoid interference without affecting feel. they're like $4, and you don't have to mutilate your keycaps :]

edit: just saw that you mentioned these before! they work pretty well from my experience
« Last Edit: Thu, 18 November 2021, 04:40:53 by stidal »

Offline theosuxxx

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Re: Advice on Grinding My Keycaps (Interference)?
« Reply #6 on: Mon, 22 November 2021, 21:40:58 »
fwiw, olkb has washers that fit around the stems and raise the keycap enough to avoid interference without affecting feel. they're like $4, and you don't have to mutilate your keycaps :]

edit: just saw that you mentioned these before! they work pretty well from my experience

The genius designers at Filco decided to make two of the R5 keys north-facing, so I was planning on buying some anyway. Got them in the mail yesterday and tried them out. They do get rid of the interference, but they make the keys sound a little different. On the mods and spacebar, they worked after about 3 or 4, but it raises the keycap noticeably. I prefer this over having mushy keys, though. Overall 4 stars out of 5 for me.

Offline theosuxxx

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Re: Advice on Grinding My Keycaps (Interference)?
« Reply #7 on: Sat, 04 December 2021, 21:00:28 »
Update: I wouldn't recommend this 'fix' to anyone else. It hasn't completely eliminated the interference on some keys, especially the spacebar. In order to completely correct it, the only solution is to use keycaps with steeper front profiles and thinner walls (e.g. Tai-Hao cubic profile, seems to work alright). I just raised the keycap with some washers and wrapped the center of the wire (where it bumps) with some masking tape. It's mushy right now, but I hope it will sound better as I continue to use it.

In conclusion, I really don't like Costar stabilizers too much, mainly because the wire sits above the plate.  :thumb: