Make a Topre/CherryMX dual use keycap

[captain]

So, I measured the stems on a HHKB key and an MX key; there is only .01" difference in diameter. Also, the Topre slice matches up with the vertical part of the MX "+".

So, I was wondering if maybe adding a slice to a CherryMX key would allow it to fit on a HHKB.  Has anyone tried taking a dremmel cutoff disk to a key to find out?



Topre: .225".   CherryMX: .215".

[swi7z3r]

I have been trying to determine this myself.  Going to take testing to know for sure, but an adapter that would allow custom MX keycaps to be used on Topre boards would be a watershed moment.  God speed.

[[Lewynlight]]

Hello,
This is my first post at geekhack, so be nice on me 
*i'm making this ID because of this thread, anyway..*

i'm clarifying this, Because i recently got a used topre (108ubk) from japan at about 150US$ with shipping,
And unfortunately they come with a very, shiny keycaps.
And i don't want to spend again for their 100buck-ish new one,so..

After compare it myself *i have several old keycaps at my old board,steelseries 7G*
I'm using some drill to make some adjustment, and it's done!

I tried to fit it, they fit okay and dont fall out when i'm turning it upside down.
But when i'm trying to fit it back to the old board, they just don't fit tightly as before 
Conclusion: be careful.. Your hybrid expectation maybe won't come as you wanted it to.

Photos coming up, i'm writing this at my ipad, tomorrow i'll have my finals, so i guess i can't post it now 
If you're reading this and waiting for photos, just fill this thread up, as i will know if there's person who is curious.


Sorry for my bad english anyway, not my mothertongue 

[jil_jil32]

Interesting, I'm waiting for your pictures Dymloslouire!

[hashbaz]

No worries about your English, we can understand you just fine.

I'm very interested in your pictures as well ... even if a dual-use set isn't feasible, being able to convert an MX set to work on a Topre board is still very exciting!

[kelske]

I've looked at this too! Thought it would be cool to be able to chuck an epic set like RainDrop on Topre.

What I noticed after closer inspections was that the stem on Topre actually arcs in a little bit at the tip.



This is dramatized for illustration sake.

It seems that this sort of pinches onto the switch sliders, and allows the key to stay firmly in place on the switch. If you just have a straight unifom cut all the way through I think they cap would seat on the switch fine but fall off easily. You'd need to have the cut at the a slightly narrower width than the switch seating rails, so that the entire cut is kinda pinching onto the switch. Know what i mean??

Very interested to see how you get on

[[Lewynlight]]

Hello,
I'm glad my english isn't that bad 
And Thank you for all of your answer. Still typing this on my ipad,so no uploads yet. Sorry!

Anyway, especially Kelske,
Yeah, you're right, long before i made this adjustment, i've been researching this with my friend *that is already got a topre* , and we also found that 'arch' (notice why you have to push the keycaps so hard to get a 'snap' sound? Actually, that is the arch effect, so without it, you won't get a snug fit.) and we've been thinking about it for since lol.

Well, the solution is using not just one, but 2 types for the drill tips!  size coming up, i'm in my campus right now x_x and i won't back to my home until wed evening *dorms..you know that well.*
I have some rotary tool that is quite easy to use to, so making the adjustment is easy.

About the technicalities, imagine the cherry mx vertically,
I'm using a small one from the tip, into about 2 or 3 mm down, and then i'm using a bigger one( not much, the difference is about 1mm, i guess..) and carve it all the way down.
On my first try, unfortunately i can't get the snap sound but it still hold in its place even when i'm turning it upside down 
I guess i should measure more specifically to get that snap sound.. By sacrificing some of my keycaps through 


But who can resist an orange geekhack keycaps in a topre board?  I can't!

[take]

now this is cool. i wouldn't try an entire set, but if i can get my black mesa or dota2 caps onto my 87U that will be the tits!!

[[Lewynlight]]

Hello, and sorry about my so-late post, final is.. quite rough.

anyway, here's what all of you waiting for!
ah, sorry for the crappy pic, cellphone camera, no autofocus.. yeah.


lovely geekhack MX keycap with topre's esc keycap


NO! HOW CAN? 


the secret of the trick!

that's still ver. 0.5 from me. after i kick all of the finals butts, i will do some more research, improving the snug fit of that keycap.

hope not to destroy it, through. GH's keycaps is very hard to get here, my friends said that i'm quite reckless to use that keycap as my first sacrifice and prototype.. still good though, i won't throw it away 

well, i'm receiving donation for your unused keycaps  jklol

also, geekhack fellow members, i need your help for giving me some ideas about merging that 4 unused key (something, space, something, KANA) into one, big space bar for me.
that key that i mentioned does nothing when i pressed it, and.. i might be merging it instead.

[kelske]

After thinking about this some more I thought about maybe looking at using a Topre to MX adapter approach rather than permanently altering keycaps. The idea would be to create a stem with the MX cross on the top, and the Topre stem on the bottom. This then sits between the keycap and switch. I'm not sure if this idea has been brought up before but it seems like an obvious solution..

Earlier this week I sacrificed an MX blue switch and Topre keycap to make a very quick and dirty prototype.





It currently sits too tall - but you can imagine where space could be saved if this was manufactured out of a single piece of plastic... Cut off the square piece of the blue, Then the stem from the cap I used is also quite lengthy, When looking at a CC topre stem you can see it's quite short in comparison, and while these don't really 'click' [as much] into place [as standard topre caps], they stay very firmly on the switch. Remove that extra length and you'd be getting pretty close..



This would end up looking something like this - ideally cast from a single piece of plastic:



There'd also be things to consider like how you make this work with different profile keys etc..
EDIT: Plus of course how you cater for stabilized keys like the spacebar!

I've got no idea where to even start in terms of manufacturing something like this.. but I reckon this would be an awesome solution. You'd get to use any MX keycap set, without damaging the keycaps - and only need one of these (assumedly cheap?) plastic adapters per key.

Thoughts?

[[Lewynlight]]

Wow.... Just wow. Haven't thought about it at all.
I'm going to find some keycaps that is worth to be sacrificed and some plastic mold!

[insilica]

Fascinating stuff. However as you say there is a height issue. I can't see how we solve this?

1) Height of adapter is the main issue.
2) how snug the fit is I.e. when you want to remove cap

 Think the adapter idea is great but you need a new thin/short neutral stem specific for adapter. Then have two adapters each for mx and topre.

This will work however will require significant amount of work down to creating a new mould.... not really worth it... I think the adapters will be relatively easy to make and cost very little in a mass group buy.

I'm definitely interested but I think the first place to start is to speak to ppl who already make caps here to see how feasible it is.

Also... this should be in making stuff section.

[CPTBadAss]

There was a project with a similar idea: Alps to MX adapters. The person used 3D printing to make the adapter (I think it was Mr. Interface from Deskthority). I heard that the adapter worked but the plastic was prone to snapping. So if you considered that manufacturing option, maybe that might not work.

[Kaysa]

Got a RF Topre spacebar that need to be replaced with a modified PBT version.
Is there any way to cut a Topre's ABS spacebar's stems and glue them onto a PBT one?

[captain]

Maybe an ABS 3D printer could "add on" precision adapters.  Has anyone tried *adding* ABS pieces to already formed ABS, or do 3D printed things have to be made all in one go?

[rowdy]

Got a RF Topre spacebar that need to be replaced with a modified PBT version.
Is there any way to cut a Topre's ABS spacebar's stems and glue them onto a PBT one?

It is theoretically possible to drill out the centre of an MX stem, carve away a notch on either side, and the MX keycap would fit a Topre stem.

I tried this, and got an MX keycap (two, actually) that would fit onto an MX stem, but teh slot I carved into it wasn't wide or tapered enuogh, so the keycap just popped off.