[WORKLOG] F75 - Custom 75% keyboard from scratch

User avatar
Flintfish

07 Oct 2014, 06:40

After modding a keyboard it’s time step it up and actually build one from scratch… Since 7bit keeps sucking up all my spare money I have no idea on how to fund this, but at least the time taken to design it is free :geek:

If I’m going to do this I’m going to build something that at least has the potential to be a daily driver, either at home or at work. A 60% would probably change the way I work too much, using Fn+HJKL for navigation, no numpad etc, but a 75% with dedicated navigation keys and a laptop style numpad accessible within a function layer might just be workable… Sadly not that many 75% exist in the first place to copy and it’s probably not the best idea really to think for myself, but at least I have you to point out my glaring mistakes…

Some design ideas:
  • Change as little as possible of the way I work, but reclaim a bit of desktop space.
  • Easy to find replacement keycaps so no odd key sizes. I want to be able to buy a blank 105 key set and use it, or join a DSA group buy without too much hassle. For the first keyset I think I’m going to order one from WASD though. That way I get to design a keyset as well and actually get the function layer properly labeled until I had a chance to learn the layout. Besides $50 + shipping for a completely custom keyset isn’t that bad even if it’s just printed ABS.
  • Probably ergo clears plate mounted on an aluminum plate. Hand wired electronics (I’ve never designed a PCB before, but learning new stuff is fun so depending on what prices I can get for a single PCB I might change my mind)
  • Costar stabilizers. I like the feel of them best and WASD sells them cheap, but so far I haven’t been able to find a template for the plate cutouts
  • Layered acrylic case with a steel bottom to add some weight and heft. (Blatantly stealing Matteo’s ideas here…). Probably looking something like Litsters designs with a proper “side” to hide the gap between keys and plate but I would like to countersink the screws into it. Feels like a big nut just in front of the space bar might get in the way.
And now on to the first draft… It ended up rather similiar to a laptop keyboard. What did I miss in this:

Image

I plan to glue spacers to the plate to cover up the gaps around the arrow keys, but replacing that low right hand corner with 1,25 keys will also work (just need to shorten a modifier). Not sure about wide arrow keys though. The gap should be similar to the one between the right ctrl and the arrow keys on a regular keyboard and that feels like a rather natural placement when I try it out on my current keyboard.

A regular teensy 2 should be able to drive this right?

User avatar
Muirium
µ

07 Oct 2014, 21:51

Yeah, a Teensy 2 could handle this no problem. 5 rows plus 15 columns is exactly the same size as my Teensy 2 powered 60%. (They have a few more than 20 usable pins.) You could use Hasu or Soarer's firmware quite easily for all you've drawn above. And it looks pretty sensible to me. The only layout worry I can spot is you're using 2x 1.25 Shift keys. Those are typically quite rare as ANSI doesn't use them. And ISO kits only have one.

User avatar
Flintfish

08 Oct 2014, 06:58

Muirium wrote: The only layout worry I can spot is you're using 2x 1.25 Shift keys. Those are typically quite rare as ANSI doesn't use them. And ISO kits only have one.
I have a feeling the Swedish keys or the 1,75 Fn key might be harder to find...
Buying two ISO kits isn't that scary after round 5 :-)

I did a sketch of a potential keyset in order to get a better feel for the board. Heavily inspired by Granite, but I really like it. This might turn out pretty good. Not sure if I want to go with "stealth"-colored legends on the Fn-lables or not. Maybe I should order a few test keys just to check color combos...

Image

User avatar
Flintfish

13 Oct 2014, 07:12

Sometimes taking time to think a design through is a good idea... I just realised that the original Round 5 still has 1.75 shifts left... That makes it possible to get rid of the questionable holes in the layout. The only compromise caps-wise is using up/down for page up/down and I can live with that

Image

Now on to the CAD phase...

User avatar
ماء

13 Oct 2014, 10:32

like broadmonkey design i think

User avatar
Flintfish

16 Oct 2014, 17:53

ماء wrote: like broadmonkey design i think
He seems like a stunning designer :-) I basically started with a choc mini and got rid of everything I don't use and added ISO. I'm sure there are plenty of similiar bords out there...

First CAD draft of the case has been made.

Image

Bottom/rear with USB connector

Image

Place inside the "foot" for a teensy

Image

Some details needs fixing but as a first draft it went pretty well. Now I need to order screws and connector to finish the design, but this should be good enogh to get cutting quotes on.

I'm thinking about having the bottom plate threaded so I don't need to mess around with nuts, and depending on price maybe cut the top acrylic layer with one matt side. The rest is pretty simple. 1.5 mm steel plates for switches and bottom (should be a nice weight to this one...) and 3mm and 5mm black acrylic layers.

User avatar
ماء

16 Oct 2014, 18:18

sym sgg would be nice in 75% imo 8-)
Flintfish wrote:
ماء wrote: like broadmonkey design i think
He seems like a stunning designer :-) I basically started with a choc mini and got rid of everything I don't use and added ISO. I'm sure there are plenty of similiar bords out there...

First CAD draft of the case has been made.

Image

Bottom/rear with USB connector

Image

Place inside the "foot" for a teensy

Image

Some details needs fixing but as a first draft it went pretty well. Now I need to order screws and connector to finish the design, but this should be good enogh to get cutting quotes on.

I'm thinking about having the bottom plate threaded so I don't need to mess around with nuts, and depending on price maybe cut the top acrylic layer with one matt side. The rest is pretty simple. 1.5 mm steel plates for switches and bottom (should be a nice weight to this one...) and 3mm and 5mm black acrylic layers.
btw you pland handwiring or with pcb?

nisilhum

16 Oct 2014, 18:46

I interested 75% recently than 60% boring, well the arrow keys comfort than TKL in my opinion
very good layout for gaming as well

User avatar
Flintfish

17 Oct 2014, 06:30

ماء wrote: btw you pland handwiring or with pcb?
I toyed with the idea of a making a PCB for a while, but I've never done it before and it would be costlier even if I got it right so I'm pretty sure this will be hand wired.

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