Making wooden keycaps for the Ergoplop

[kurplop]

I began making keycaps for my latest project, a portable ergonomic keyboard.

After months of indecision I finally committed to a slightly tighter key placement than the standard .75" o.c. vertical spacing. I didn't want to mess with the horizontal spacing but thought there was room to spare vertically and I see the advantage of the shorter reach to the top row. That explains the custom keycaps.
 ergoplop 8-30 2 pdf.pdf (24.96 kB - downloaded 319 times.)
 This is the arrangement I settled on. The blue highlights show the border if I use std. keycaps. I'm modifying a Marble Mouse to go in the center

Here are more pictures.     http://flic.kr/s/aHsjHSwPcr  I should be progressing steadily now on this project. The first step is always the hardest.

[bazemk1979]

looks nice!!!

[Thimplum]

GREATEST KEYBOARD NAME EVAR!

Nice caps, btw.

[MOZ]

Amazing work sir.

Wish I had such good wood working skills.

[OldDataHands]

Looks promising in all ways!  Rock On!

How're you planning to connect to MX switch ?

[kurplop]

Looks promising in all ways!  Rock On!

How're you planning to connect to MX switch ?

The simple answer is, I'm not.  Actually, I decided to go with Alps switches. I plan on relieving the underside about 3/16" then mill a 3/32"x5/32" slot in the center of the cap bottom. Then epoxy a corresponding stud into the slot. I tried casting urethane caps and I learned a lot but I think this may be quicker in the long run and certainly less common if I use wood. Better something I understand (wood) than risking unpredictable results with casting.

I plan on soaking the caps in CA to further harden them, then put a surface finish on them.

The Alps decision was influenced by their dimensions.  0.5"x0.6" vs. 0.55" square for the MX switches. While the cherry switch could fit, the Alps will be easier, both dimensionally and in the simplicity of the connection. Plus I have to say, the Alps sound great.

[ften]

Woah, nice work.  What type of wood is it?  Are you planning on varnishing them or anything?

How're you planning to connect to MX switch ?

I'd like to know this too.

[kurplop]

When I cast urethane MX caps, I hot glued donor MX barrels into my mold. They held really well. If I were to use MX switches I'd probably do the same; just glue the guts of a donor cap into the wood caps. I don't think that making such a small barrel out of wood would be as reliable. 

The wood is maple. See finishing plan above. I posted while you were writing.

[Larken]

your mod has gotten even more intense, and that's saying something.

on the topic of harvesting stems, it brought to mind an old video I saw a year back or so that might be of interest to you.

it was from a steampunk themed mod done by Jake Von Slatt, which I thought was rather interesting (the workflow especially), and the final product used the stems attached to labelled shirt buttons or similar shaped discs to create his custom caps.

a log of his full project can be found here; http://steampunkworkshop.com/keyboard.shtml

[kurplop]

on the topic of harvesting stems, it brought to mind an old video I saw a year back or so that might be of interest to you.

Impressive. What a great way to harvest stems. That could probably be done with a square tube and plunger to more easily align the stems with the keycap.

[AndyCapets]

WOW that looks really good! Any interest on making more to sell some ?

[kurplop]

Thanks.  Assuming I actually succeed in making them, I'm afraid that the price would be cost prohibitive.

Maybe some day when I get a CNC mill.

[Tarzan]

Interesting to see someone harvesting old Chicony keycap stems.  I'll have to check out the build log to see what he's made with them, I recently got a nice example of this rubber dome brand from Slovakia.

your mod has gotten even more intense, and that's saying something.

on the topic of harvesting stems, it brought to mind an old video I saw a year back or so that might be of interest to you.

it was from a steampunk themed mod done by Jake Von Slatt, which I thought was rather interesting (the workflow especially), and the final product used the stems attached to labelled shirt buttons or similar shaped discs to create his custom caps.

a log of his full project can be found here; http://steampunkworkshop.com/keyboard.shtml

[gcb]

Did this end up well?

thinking about putting a CNC mill to good use...

[kurplop]

Like many of my ideas, I get so far and either lose interest, run out of time or discover a flaw in the idea. In this case it was a little of all three.

The primary reason I abandoned the wooden caps is the wall thickness I was working with. Because of the limited space between the Alps switch and the reduced keycap spacing I chose, the cap walls needed to be under .04" thick, which may be too thin for a wooden cap wall to be reliable. I was also concerned with my ability to repeat such close tolerances necessary 70+ times.

I did all the initial cuts on a table saw and made the contoured tops on an oscillating spindle sander. The top side ended up looking good but nowhere near accurate enough to properly index them on the mill with consistent results when I cut the pocket and stem on the underside. I have since milled new prototype caps out of aluminum and will make molds to cast urethane caps soon.

Most failed project I've worked on have at least taught me something. In this case I learned several things.

   - Accurate repeatability can be very time consuming with manually controlled equipment.

   - Alps switches, while their .60"x.50" footprint is better proportioned for my unconventional switch spacing of
  .75"x.65", the clipped pyramid shaped top of the .55"sq. Cherry switch actually allows a smaller pocket in the
  underside of the  keycap.

   -The Alps have a looser stem design, the effect of which is amplified the taller the cap sits above the switch.

   -If I stuck to the wood design, I would have likely not used wood for the cap stem, at least in the cross grain  orientation. It would have definitely failed. I was planning to cut a slot in the underside of the cap face and glue in wood stem inserts with the grain running vertical. Alternately, I could have cut the entire cap with the grain facing up. Structurally, that would have made more sense for the thin side walls as well.


With a CNC mill you would avoid some of the limitations I encountered. I would recommend using a wood with a tight grain like maple or some of the dense tropicals. I would also consider orienting the grain vertically. Naturally, with standard sized key spacing, you will also have more room 'under the hood' to work.

Best wishes and keep me posted. I'd love to see the results.

 

[gcb]

Terrific insight. thanks for sharing your lessons!

I still need to read up on wood grain and such... as i never really worked with wood in such tight spec projects.

after reading your post, i will probably think about a plan B by making a "bed" with a ABS 3d printer... think a T shape with a MX steam, and plane on top. and then i will attach the wooden "cup", i.e. the keycap, on that plane. maybe glue it. or even printing *in* the wood cup! that should be interesting...

Well, i will probably try to CNC the heck of that cap in one piece first   but it all will depend on how much the owner will want to devote to the project as well.

thanks again.

[gcb]

i saw there is a humongous 3d printing thread, but anybody arriving now won't make heads or tails of it... so i'm posting here since this is where the idea came from

here is the 3D cherry MX keycap mount. Did it in openScad as it is the only 3d application i stand to use nowadays. there is also a STL file if anyone want to use on non-openscad (inferior applications.