Oh boy. This reply got really long. Sorry about that.
This looks superb; nice work.
Thanks! (And thanks for open-sourcing the design!)
Do you mind sharing how much it cost?
I'm not sure if you meant the case or the whole build, so here is the list of all the parts I used (some prices are approximate).
| Description | count | Materials | Labor | Shipping | Total | Source |
|--------------------+-------+-----------+-------+----------+--------+----------------------|
| Case | 1 | 9.50 | 19.07 | 25.74 | 54.31 | Ponoko |
| #6-32 or M3 screws | 8 | 1.25 | | | 1.25 | Lowe's |
|--------------------+-------+-----------+-------+----------+--------+----------------------|
| Cherry MX Browns | 50 | 29 | | 4.82 | 33.82 | Mechanical Keyboards |
| Keycaps (set) | 1 | 25 | | 4 | 29 | Signature Plastics |
| Teensy 2.0 | 1 | 15.95 | | 4.07 | 20.02 | Adafruit |
| Jumper wires | 40 | 2.75 | | 1.99 | 4.74 | Amazon |
| 1N4148 diodes | 50 | 2.69 | | | 2.69 | eBay |
| Mini USB cable | 1 | 0.0 | | | 0. | desk drawer |
|--------------------+-------+-----------+-------+----------+--------+----------------------|
| Cherry MX Reds | 5 | 10 | | | 10 | Mechanical Keyboards |
| Rubber o-rings | 125 | 8.99 | | | 8.99 | eBay |
|--------------------+-------+-----------+-------+----------+--------+----------------------|
| Total | | 105.13 | 19.07 | 40.62 | 164.82 | |
#+TBLFM: $6=vsum($3..$5)::@12$3=vsum(@2$3..@11$3)::@12$4=vsum(@2$4..@11$4)::@12$5=vsum(@2$5..@11$5)
I got what was called the "ErgoDox Base set" at Signature Plastics (44 1x keys and 12 1.5x keys), thinking that this way I can get 2 1.5x keys plus the extra keys I get are a bit more useful compared to getting the base set for a regular keyboard.
After removing extras the cost minus shipping could still be around $100.
In addition to this I had to get some tools:
| Description | Materials | Shipping | Total |
|----------------+-----------+----------+-------|
| Solder | 2.93 | 2.75 | 5.68 |
| Magnet wire | 8.99 | | 8.99 |
| Helping hands | 16 | | 16 |
| Soldering iron | 20 | | 20 |
| Hot glue gun | 9.81 | | 9.81 |
|----------------+-----------+----------+-------|
| Total | 57.73 | 2.75 | 60.48 |
#+TBLFM: $4=$2+$3::@7$2=vsum(@2$2..@6$2)::@7$3=vsum(@2$3..@6$3)
Does Ponoko charge by area rather than by the amount of time the laser spends cutting?
Well, it's both, in a way. Any design has to fit into one of the templates; they have three (or four) sizes called P1 (181mm x 181mm), P2 (384mm x 384mm), P3 (790mm x 384mm). Some materials allow using the 24x12 template (596mm x 291mm). If a design does not fit in a template, you have to buy another full "sheet" of one of these sizes.
In addition to this you pay for the laser cutting time and shipping. The cutting time is computed automatically using the design you upload and the selected material (this makes it easy to optimize the SVG file -- just upload a new version and Ponoko immediately tells you the price).
They ship the whole sheet your design is cut from, held together with backing paper -- scraps and everything. The shipping cost depends on the weight (pounds per sq. foot) of the chosen material, the templates size, and -- of course -- the distance.
So now you see why I wanted to be able to fit everything into one thin, cheap, and light sheet of plywood.
If so that could be a big influence on how you structure the layers; I was more concerned about total cutting time.
Yes, cetrainly. I could probably bring the price down a bit by combining cuts but decided that it was not worth my time.
Am I right in reading that you ended up with three spacers, leading to a total of 9mm spacing?
Yes. The main limiting factor was the mini USB cable I used: it has a 8mm thick connector.
That's interesting. I was just barely able to make it fit in 6mm, but someonen else built an Atreus with a 5mm spacer, and I was surprised to see he made it work: http://blog.tarn-vedra.de/2014/04/reproducing-keyboard-science_1707.html
I might try to shave some plastic off of the USB connector with a utility knife and take out a spacer. I'll let you know how it goes; if it does work, this will be the thinnest Atreus build of the three! (Now it's 2mm thicker than the one by Moritz Ulrich (3 + 5 + 5 + 3 = 16mm), and 1.5mm thicker than yours (3 + 4.5 + 6 + 3 = 16.5mm), I believe.)
It's interesting to see the changes you made to the case. Apart from the changes to the spacers and the screw holes, it looks like the other main difference is the way you made the top layer follow the outline of the keys more closely with a stairstep pattern instead of straight lines that follow it more loosely. I really like how that turned out. I would be open to using your design as the canonical Atreus case if you're up for it, especially given that one of the goals is to make it accessible to people in your situation who may not have local access to a laser cutter. (I would at least like to make the option of dropping one layer of spacers to bring it back to 6mm, but we can discuss details later.)
Yes, those are the main differences. I'm happy to contribute all the case design files if you're interested. I can easily create a version with "regular" (not quartered) spacers, by the way.
Note that my case is a little bigger, though (257mm x 116mm).
Regarding the stairstep pattern: I also think that it turned out nice, but I would probably make the cutout smaller: now cuts the in the top plate are 1mm away from holes in the switch plate, but I think we can go down to 0.5mm.
I'm thinking of building another board in wood; do you think you could provide links to the finishing techninques you used? I haven't done much with wood before.
Heh. I'm definitely not an expert. I wanted a food-safe finish (I'll be touching this thing a lot, right?) and used what I had at hand. If I were to do it again, I would probably use paraffin wax or a mixture of mineral oil and beeswax (see links below).
Here's what I would do.
Make sure that I kept the funny-shaped scrap piece cut out from the top plate.
Assemble the case without the switches, probably sandwiching a sheet of thick paper between the switch plate and the top plate (you don't want to finish the switch plate or gluing to it might get a bit hard, but you do want to sand its edges). Then put the piece cut out from the top plate into the spot where it came from and start sanding with circular motions. I would start with a #180 grit sandpaper and see if it gets the case smooth enough for you. If not, switch to #320 or similar after a while, which should be sufficient.
Then apply the finish as described, say, here:
https://www.finewoodworking.com/how-to/article/food-safe-finishes.aspx or here
http://www.leevalley.com/us/shopping/TechInfo.aspx?type=a&p=59381 It's very hard to mess up.
If you can think of any other changes to the assembly instructions I posted that would be helpful to future builders, please feel free to send a pull request my way.
Will do! (You have a couple of pull requests waiting right now, by the way.)