Modding my Leopold FC660C


Hi Friends -

Good evening and happy Thursday. I hope you are well.

I recently purchased a Heavy-6 because I make good financial decisions, so now I am working on modding my FC660C to match the case in all of its endgame glory. My current plan is to install the following: a Hasu controller, BKE lights, and KBDFans 1U Topre to MX sliders on the 1U keys.

With that being said, my questions are as follows:

  1. Is it possible to completely convert an FC660C to MX sliders?
  2. If not, does anyone have leads on where I could buy a set of FC660C modifiers?
  3. Are there any mods that I am missing? I know lubing is a thing, but I want more experience with the board stock first.

Thanks in advance, everyone, and happy clacking!



MX Sliders seem great, and I’m not discouraging you, but they are super wobbly, even the “better” designed ones from KBDFans. As soon as I modded my 87U, I swapped the old sliders back in, because of the wobble. As for modifiers, KBDFans Topre to MX Sliders should include the stabilized keys, but not for the spacebar. Most people just use the stock spacebar for MX-Topre builds. Lubing reduces the sound, but I prefer the feel of unlubed Topre over lubed.


I agree with yalox, the aftermarket sliders that are offered are too wobbly for my tastes. I had scrapped my Realforce RGB and harvested the stems from there and they’re way less wobbly.

There’s a slight difference between cherry profiles and topre profiles. I’d recommend just switching out the modifiers and just leaving the spacebar as it is. You would have to drill the enter, backspace, and both the shifts.

Good luck with your mods!


Silence-X rings? I use them on the 1U sliders and put bandaids on the stabilized sliders.

Dielectric grease on the stabilizer wires would also help with any rattling.


Thank you for the heads up. My main struggle with my FC660C is the keycaps, so I’m going to give the sliders a go even if they are not a permanent modification. Seriously, the blacked out keycaps may as well not have printing on them for as hard as they are to read in basically every lighting condition (IMHO).

I also have new caps picked out for the board if the conversion is acceptable ( katakana WoB).


Eek, that sounds dreadful. I am not a particularly handy person by nature, so the idea of performing a permanent mod (like drilling) is outside of my comfort zone at the moment.

I am also considering just biting the proverbial bullet and buying a Novatouch to harvest those sliders, but we’ll have to see if I hate my wallet that much.


Could you explain the bandaid mod in a bit more detail? I’ve seen it mentioned in a couple of different places, but I’ve never really understood how to do it myself.

Thank you in advance.


It’s sorta an alternative for o-rings for the 2u keys. Not 100% necessary. You might even find that doubling up on an o-ring has the same effect.

With the mod you cut out a rectangle from the adhesive portion of a fabric bandaid and place it on the inside of the 2u sliders. It’s fine to go over the width but not the length. (Since the fabric will get stuck between the slider and housing)



I just finished converting one of my FC660c to MX today.

I used the KBDFans sliders and some 3d printed stabilizers for the space bar.

  1. No issues with the 1u sliders
  2. The 2u sliders needed a little sanding (I used 220 grit paper) on the long edges to stop them from occasionally getting caught up in the housing.
  3. You need to drill holes in the housing so the stabilizer stems of the stabilized keys don’t impact the housing. I did not do a good job on this and came close to really messing the housings up. You could alternately remove the stabilizer stems from the keycaps if you are sure you are not using them anywhere else.
  4. The 3d printed spacebar stabilizer worked really well, once I made sure it was correctly installed (there is a left side and a right side for the 6u stabilizer). Expensive but worth it. You do need a 6u spacebar with a center stem, GMK sets are generally your best bet, I was lucky enough that /dev/tty supported that config (though I had to source the spacebar from someone else).
  5. The keyboard is noticeably noisier now than with the stock setup. I was not happy with the fiddliness of the KBDfans silencing rings, so skipped them, but may look at a different solution in the future.


Thank you for the in-depth response. I really appreciate it! :slight_smile:


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