deskthority

Looking at all these mods/custom keyboards that people are making has made me want to make a keyboard of my own--more specifically, a low profile mechanical keyboard.

I am probably going to go about doing this by making my own keycaps, but I am unsure whether to make them more similar to the Cherry G80-3800 shorter MX keycaps (small typing area) or the Cherry ML/Topre Shortthrow keycaps (gets stuck if hit off center). The G80-3800's problem is fixable by tweaking the design but does anyone have any idea how to change the ML key cap's design so that it doesn't get stuck?

I am going to start learning how to make CAD's after I decide which keycap model to use, so I was wondering if anyone has CAD's of any type of keycaps? Although, I'm ultimately aiming at making a different keycap, a CAD of a normal Cherry MX keycap would be fine too since I doubt many people have had a need to make a CAD out of the other keycaps. Also, any related CAD's (switches, etc.) would be welcome if anyone had some they'd be willing to part with.
I personally do not know how people make the CAD's so accurate; do they create it manually or with a laser scanner? Would it be terribly hard to make my own model of a cherry ML keycap?

Lastly, after constructing CADs, how do people make their models come to life? Through 3d printing?, CNC?, Etc? I was thinking 3d printing through shapeways, but I'm not sure if it would be the cheapest way to do it.

Thanks so much for any help you guys can give.

I do know CAD keycap models exist: There were some really nice looking ones that someone had posted on GH (In the group buys section, I do believe: There were some topics about getting Ti, Al or Steel spacebars and other keycaps made). Unfortunately, I don't have the files, and I don't remember who made them.

As far as what model to make: I recommend IBM's keycap shape. They have a fairly large top area for fingers, and the cylindrical feel is very nice. If this doesn't make sense for your application (like if you want a sculpted profile) then I would change the recommendation to merely emulating the large finger area on the top.

I think the cherry ML's get stuck if hit off center is more a function of the keyswitch than the keycap. I haven't looked into it in any depth, though.

As far as bringing CAD files to life: there are several ways that you mentioned, but there are some things to watch out for. Since the keycap has empty space underneath, it might be hard (or impossible) to make with certain types of 3D printing. I always recommend SLS (Selective Laser Sintering) as once the laser is done sintering the particles, you just pour the excess off (the loose particles support the top of the key cap, and become empty space when poured out.

SLS might be expensive and hard-to-find, though. You can probably go with shapeways.
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I hope others are able to offer more advice.

Thanks for the reply!

The top part of the keycap would just be personal ergonomic/aesthetic preferences, but I don't know where to start with the underside of the keycap thickness wise as well as the area where the switch fits. CAD-wise, I've sent some pm's out but I just don't know whether it's too much to ask since I don't know how much was their personal design.

Also, regarding your suggestion, the IBM keycaps are probably individually shaped by row like the other mechanical keyboards which seems a bit too difficult so I'll stick with one uniform keycap for my first attempt. I'll keep it in mind though =]
Duly noted on the ML switches.

Is shapeways SLS though? I was under the impression that it was a 3d printing company or is it more specifically 3d modelling? The cool DIY thread in this subforum mentioned the sintering used by shapeways too so I was a bit confused. I know for a fact that people make complicated rings out of silver at Shapeways though so I think it should be fine as long as the top horizontal surface isn't count as too big of an overhang.

No, all the IBM keycaps are the same. Only the width differs (and height for ISO enter) The "profile" is because the membranes and barrel plate is curved. (I didn't see this in my quick search of the wiki, though). Sticking with one uniform keycap worked for them. (Though flat profile wasn't that bad: I like my Cherry G84)

Shapeways mainly does 3D printing. They do have a sintered ceramic as one of their materials, and I suspect their ceramics and metals are SLS. There is at least one other place (I forgot the name) that also does this.

Either way, they will tell you what is possible with their process and material.

A lot of materials from shapeways are SLS. Inclusing the cheapest "white strong and flexible".
http://www.shapeways.com/materials

I see... that works then
From what I've seen, shapeways had the best prices and a good reputation.
But ohhhh right, I remember reading about the curved frame too. I'm probably gonna stick with a G-84 esque design though to keep that flat image since I feel like the curve would be even more pronounced with shorter keycaps.

Fortunately, I found a person generous enough to share CAD files with me so I guess keycap wise so now I have a foundation. I guess the hard part will just be just how short I can make the slot where the MX stem fits (cruciform?) while still keeping the keycaps firmly in place. I guess I'll have to buy a G-84 myself to see how they did it.

Also, on a separate note, I've seen a lot of people put a lot of importance in the thickness of the cap. Is it that significant of a visible/tactile difference?

geotang wrote:Also, on a separate note, I've seen a lot of people put a lot of importance in the thickness of the cap. Is it that significant of a visible/tactile difference?

I wouldn't say so. I have thick WYSE keycaps, cherry keycaps, thin SP keycaps, etc. There isn't too much of a difference, though I imagine it'd be more pronounced with the resonation of bottoming out, though.

If you're reproducing a keycap for cherry ML, I imagine the effect would be less pronounced. I have no data, but I imagine the "click" of cherry blues wight have a different frequency based on the keycap, but I really ting this would be slight, or undetectable.

Really, thicker keycaps are "better" in my mind because they should be more resilient to dropping or stepping-on. Also, there is a heavier weight to the final keyboard, which may feel like better quality. In practice, as long as they can withstand being typed upon, any thickness should do.

Also, as ABS ages, it turns yellow (like WYSE sets) and gets slightly harder and more brittle (as the US radiation crosslinks the polymer, I believe. Since a thicker keycap starts with a higher ultimate strength, even fully yellowed, it'd be stronger than a thinner keycap. Also, a thicker one will take much longer for the "inside" to get brittle from UV or other sources. If you plan on keeping your keycaps for more than a decade or so, this should be a consideration.

Finally, it'll take longer to physically wear through the keycap. Keep in mind most of these aren't really concerns. There was a topic posted at GH where someone compared the tow, and preferred thinner keycaps.

Myself, I believe material matters much more, and I try to go with PBT/POM. My "spare set" is some excellent (thanks Quarzac!) condition lasered POM from cherry. All my "daily Driver" keyboards have PBT. Thickness isn't much of an issue for me.

But if you are printing them from scratch, why not have the maximum possible thickness to just barely clear the switch body?

Also, look into the possibility of ceramic keycaps. I'd very much like to get some. Did you know it's possible (even easy) to dyesub ceramic? I just wish we could get unglazed ceramic from shapeways. The glass of the glaze ultimately holds it together, as it seems they don't have the ovens to sinter them properly (it'd take at least 4Hours at 1000-1200C, and with a decent heating and cooling schedule, would tie up an oven for the best part of a day.)

I wouldn't say so. I have thick WYSE keycaps, cherry keycaps, thin SP keycaps, etc. There isn't too much of a difference, though I imagine it'd be more pronounced with the resonation of bottoming out, though.

Most SLS plastics that I know of are unfortunately quite weak and bend easily if thin. It is hard to break them though, and will deform elastically to a large degree and return to its original shape with no fracture. I think that typing on those, you might feel some flexing if you don't hit they cap in the center so that the load is taken up by the stem. If you are to make them via that way, I would make them rather thick and with supports inside to spread the stress in the material.

There are several companies that deal with this other than shapeways, However, I do not know how many deal with non-company private buyers. Perhaps Materialise could.

Having created quite a few keycaps for my custom keyboards I want to share my experiences here: I was never really satisfied with the results of my laser-sintered keycaps, mainly due to their rougher surface. Then again I did not polish or tumble them after production, but with the curved design I imagined that would not have help very much. Furthermore, the original Cherry MX caps are simply most comfortable to type on and obviously very well designed in regard to slopes and dimensions for the different rows, so I have always come back to using them instead of customs ones. You should put more time into getting a decent layout of the keys, imho. Otherwise designing keycaps from the readily available geometry specs is probably a good and easy exercise in CAD.

@dorkvader
Thanks for your extremely detailed opinions *_* I appreciate it a lot
I don't understand what you mean by barely clearing the switch body though. Can't really picture what you mean.
Also, yeah ceramic keys sound cool! They're also one of their cheapest materials but ceramic along with glass just sounds dangerous.. I imagine even the sides would have to be decently thick to avoid shattering.

@damorgue
I'll keep that in mind.. and probably try to go for a relatively thicker keycap. Once I actually can make CAD's I'll give Materialise a shot but as of right now, they don't have prices of their materials per cm^3 I don't think so I'd need to quote to compare.

@suka
For a first attempt, I think a flat uniform surface would probably be easiest to shoot for. I also have yet to compare the short profile and normal keyboards with each other so I will definitely give normal keycaps a shot. It's just that designing my own keycaps and later on, my own keyboard, is really interesting to me.

Also, to further expand on the pm I sent you one more time, I went into the post-production subforum of Shapeways and found that sandpaper worked well on metal and their plastic. They suggested going up gradually in fineness of sandpaper although I guess that's common sense. People also suggested covering plastics with a white putty to fill in bumps.