Safe Cure for Loose Cherry mx Keycaps on CM Novatouch?

[Hypersphere]

After putting a new set of dye-sub thick PBT keycaps on my CM Novatouch, I find that some of the caps pop off when typing. As you might expect, this problem is made worse by installing O-rings on the keycap stems.

On a regular Cherry mx keyboard, loose-fitting keycaps can be tightened up by putting a small piece of "cellotape" ("Scotch" tape) over the Cherry switch stem and then reinserting the keycap. Can this be done safely with the hybrid Topre switches in the CM Novatouch? I would not want to have bits of the tape coming loose and possibly gumming up the works of the Topre switch. Are there straightforward alternative methods for making the keycaps fit more securely?

[GeorgeK]

I use a tiny square of paper rather than tape.  I'm not saying that this would be 100% safe for the nova but it definitely wouldn't gum up the switch.

[absyrd]

Tiny square of cling wrap?

[jacobolus]

Yeah, plastic wrap works great. Just fold it over in as many layers as it takes to give you a snug fit (probably 1-3 layers).

[dorkvader]

This is very common with (for example) imsto keycaps (they seem to be a bit bigger I think?) and some stabilizers.

I use bits cut out of plastic baggies, but clingwrap shoudl work as well. Paper is hit or miss in my experience, but it could work for you.

[Hypersphere]

I know that tape, post-it notes, paper, and plastic cling-wrap all work relatively well for helping to secure Cherry mx keycaps to Cherry mx stems, but I was not certain about the hybrid Cherry mx-compatible stems in the CM Novatouch Topre switches. If the cross-stem inside the Topre slider does not open into the inner workings of the switch, then I suppose that if bits of cling-wrap etc. were to fall into the stem, it would not do any damage. I will probably just try it and see how well it holds up over time.

An advantage of original Topre switches and some other switch types, such as IBM Model F and Model F buckling springs, is that the keycaps snap securely into place rather than being held on by friction. However, as we all know, a great advantage of Cherry mx-compatible stems is the hugh variety of keycaps that are available.

[Hyde]

1)  You can use plumber's tape, those are a bit softer and more flexible.

2)  Take off the o-rings, it doesn't do anything in Topre switch.  Like literally it doesn't help you with the sound or anything at all it just makes your keycap pop off faster.

3)  Yes imsto keycaps are notorious for being loose even on Cherry stems.

[jameslr]

I have this same problem with my GMK Dolch. I ended up putting the Leopold PBT caps on it and those are fine. My Filco doesn't have that problem with the GMK dolch.

[tp4tissue]

plastic wrap is better than tape, because the glue eventually gums up, or pumps out.. and you have to do the thing again.. and it'll be all sticky or powdery.

[jameslr]

After putting a new set of dye-sub thick PBT keycaps on my CM Novatouch, I find that some of the caps pop off when typing. As you might expect, this problem is made worse by installing O-rings on the keycap stems.

On a regular Cherry mx keyboard, loose-fitting keycaps can be tightened up by putting a small piece of "cellotape" ("Scotch" tape) over the Cherry switch stem and then reinserting the keycap. Can this be done safely with the hybrid Topre switches in the CM Novatouch? I would not want to have bits of the tape coming loose and possibly gumming up the works of the Topre switch. Are there straightforward alternative methods for making the keycaps fit more securely?

For what it's worth - I think resolving this issue will change your opinion of the Novatouch. The loose caps add a "rattling" quality to the sound of the board and make it feel cheap and less solid. Switching to the Leopold caps that didn't fit as loose were a world of difference. I think you'll like it a lot better. But if you've already made up your mind about the board - there likely isn't anything that can change your mind about it other than continued (ab)use.

The GMK caps were so loose they would fall off if I turned the board upside down. This is what prompted me to swap them out. I'd like to note the GMK caps were also a bit loose on my QFR as well. Not sure it's a problem specifically with the Novatouch, but it might be.

[Hypersphere]

1)  You can use plumber's tape, those are a bit softer and more flexible.

2)  Take off the o-rings, it doesn't do anything in Topre switch.  Like literally it doesn't help you with the sound or anything at all it just makes your keycap pop off faster.

3)  Yes imsto keycaps are notorious for being loose even on Cherry stems.

Thanks for (1), although I think I will try cling wrap to avoid using anything with adhesives. I agree about (3), but the Imsto caps seem looser on the Novatouch than on my regular Cherry mx keyboards. Regarding (3), I agree that the O-rings cause the caps to pop off more readily, but the O-rings do change the sound. I was getting a lot of clicking sound from bottoming out, and the O-rings suppress that. However, they of course do nothing for the upstroke "clack" or the stabilizer rattle.
 

[Hypersphere]

After putting a new set of dye-sub thick PBT keycaps on my CM Novatouch, I find that some of the caps pop off when typing. As you might expect, this problem is made worse by installing O-rings on the keycap stems.

On a regular Cherry mx keyboard, loose-fitting keycaps can be tightened up by putting a small piece of "cellotape" ("Scotch" tape) over the Cherry switch stem and then reinserting the keycap. Can this be done safely with the hybrid Topre switches in the CM Novatouch? I would not want to have bits of the tape coming loose and possibly gumming up the works of the Topre switch. Are there straightforward alternative methods for making the keycaps fit more securely?

For what it's worth - I think resolving this issue will change your opinion of the Novatouch. The loose caps add a "rattling" quality to the sound of the board and make it feel cheap and less solid. Switching to the Leopold caps that didn't fit as loose were a world of difference. I think you'll like it a lot better. But if you've already made up your mind about the board - there likely isn't anything that can change your mind about it other than continued (ab)use.

The GMK caps were so loose they would fall off if I turned the board upside down. This is what prompted me to swap them out. I'd like to note the GMK caps were also a bit loose on my QFR as well. Not sure it's a problem specifically with the Novatouch, but it might be.

Update: The keycap on the "O" key on my Novatouch is so loose that it pops off while I am typing, and it falls off when the keyboard is inverted. To test whether the problem was in the keycap or the switch stem on the keyboard, I reversed the "I" and "O" keycaps. Now it is the "I" keycap that pops off while I am typing and falls off when the keyboard is inverted. Therefore, it appears that the problem resides in the switch stem on the Novatouch. Of course, there are workarounds for such problems, such as putting some tape or plastic wrap in the keycap. Nevertheless, CM ought to take a look at this issue. It might just be a matter of tightening up the tolerances on their quality control procedures. Its seems that the stems might be a tad too small on all of the keys, and there is obviously some unevenness to the degree of looseness from one key to another.