deskthority

The Left Control Key of the Topre Realforce 87U (RF 87U) is designed differently from other keys on the RF87U. This is due in part in order to accommodate an LED. An image of the L Ctrl (from Muirium) is shown below:
In addition to the other peculiarities of this key, the base of the slider is too small to keep a Silencing Ring properly seated, which can impede the return stroke of the slider. Therefore, a Silencing Ring should not be installed on the Left Control key of the RF87U.

The Left Control is the only key on the RF87U with this limitation. There is no problem with Silencing Rings on other keys with LEDs (e.g., the Caps Lock and Num Lock keys). There is also no problem with Silencing Rings on wide keys with or without stabilizers (e.g., Backspace, Tab, Backslash, Caps Lock, Enter, Left Shift, Right Shift, the wide keys adjacent to the Spacebar, Spacebar, or Right Control).

Silencing Rings work fine on all keys in other Topre-switch keyboards, such as the HHKB Pro 2, RF104U, Leopold FC660C, and the CM Novatouch.

Note that Left Ctrl on a HiPro does use the same slider design as the rest of the keyboard. This peculiarity makes it difficult to build a TKL HiPro as well.

How so? What does TKL have to do with it?

I think XMIT means transplanting the Hipro "housings" in a 87U

Oh right. "Build" threw me off. I thought he was talking about Topre doing it, not us assembling our own.

Looks like the 87U's plate needs drilled to accept a real Topre switch shell there. Ugh. Stupid Topre ever pulling a damn fool stunt like that, just for a blue LED!

Anyway, that's not the only thing between me and a HiPro TKL. I could never leave a Topre stranded, naked like that! And the best HiPro is JIS so incompatible with my layout anyway. I'd rather just use it as is.

Muirium wrote: Oh right. "Build" threw me off. I thought he was talking about Topre doing it, not us assembling our own.

Looks like the 87U's plate needs drilled to accept a real Topre switch shell there. Ugh. Stupid Topre ever pulling a damn fool stunt like that, just for a blue LED!

Anyway, that's not the only thing between me and a HiPro TKL. I could never leave a Topre stranded, naked like that! And the best HiPro is JIS so incompatible with my layout anyway. I'd rather just use it as is.

In my case, it was a red LED (The "EK Edition" of the black all-45g RF87U). Nevertheless, although I prefer red LEDs to blue, I don't understand why they had to make such an oddball switch for the Left Ctrl. For example, the CapsLock and NumLock keys have LEDs, but the switches are normal, and consequently they accept a Silencing Ring with no problem.

Fortunately, the Left Ctrl on my RF is a relatively quiet switch anyway, and I almost never use this key. I've used the RF87U DIP switch option to swap CapsLock and Left Ctrl, and I seldom use CapsLock.