Autocad 60 Keyboard Pcb Drawing
So now that you've gotten some ideas about how to build a keyboard, it's time we get started. In the interests of making this project as accessible as possible, I'll work through my keyboard, to the greatest possible extent, in order of increasing complexity. When it comes to the actual keyboard build and assembly then, we'll be starting with the non-electrical features; namely, the casing.
Case Parts
At the very minimum, you'll need a plate or PCB to hold your keyswitches, and a bottom
case. As I mentioned earlier, it won't simply suffice to cut out a plate much like the one in the image, get a thick piece of wood and cut it as a rectangle (or whatever shape you intend to have your keyboard) and call it a day. Regardless of whether or not you have a PCB, the bottom of your mounting surface is bound to have something coming out of it (Cherry and Cherry derivative switches all extend past the solder point, and switches mount about halfway down on plates), so you'll need some empty space below your plate. As for acquiring the pieces to your custom mechanical keyboard, you have a few solid options.
First, if your keyboard is in a traditional or commonly found layout, there's a fair chance you can buy plates and casing online. Even if you're into a more ergonomic style, the ErgoDox has PCBs available online. If you wish to save yourself the hassle of using CAD software (which is neither cheap nor beginner-friendly), Keyboard Layout Editor allows you to build a custom keyboard layout, and there are multiple sites which will accept raw data from the layout editor. Massdrop also frequently drops DIY keyboard kits, so you can simply buy one and not worry about sourcing parts.
However, if you're interested in doing some of the dirty work, have access to high precision tools, wish to save money, and/or have a highly customized layout, you may be staring at your computer with CAD software, wondering, "why did I choose this life?"
Today's blog post will enable you to build a design with AutoCAD (as a student, I enjoy free AutoCAD, so it will be the software of choice) for plates and cases. We won't be covering how to build PCB files, for two main reasons. First, as I personally cannot afford a PCB, I haven't looked into building one, so I have no experience with Gerber files and PCB tools, and my keyboard building is taking priority. Second, as I suspect most are in a similar boat, the demand is unlikely to be nearly as high. Nonetheless, if time allows post building my keyboard, I will find and learn PCB software and blog about it.
Important Drawing Files
Before we get started with Autocad, we'll need some files. We'll refer to all Cherry and replica switches from this point on as Cherry switches, since their technical details/dimensions are identical. As the Cherry specifications show, the switch holes are not exactly easy to design. Fortunately, GeekHack and Deskthority, two enormous resources for custom keyboards, have provided substantial resources for design.
The first set of files we'll need are some keyswitch layouts. You'll notice that everything comes in sets of four, because there are four different ways you can cut out a switch. Here's a look at the standard 1 unit (1u) sized keyswitch; these are intended to fit a single switch, and a single keycap (like a standard alphanumeric key).
You'll notice each of the four key cutouts has a 19*19 mm square around it. This square simply shows the space taken up by a single key, since keycaps are 19mm*19mm at 1u size. Option number 1 is a simple 14mm*14mm square; this is the minimum which allows you to mount a switch. Option number 2 allows you to mount a switch with the LED either facing up or facing down, and, in the event that you wish to remove the top of the switch (to change springs or whatever), enables you to do that. Option 3 is similar, but you can place the switch in whatever orientation you desire. Option 4 works like option 2, but with less cutting involved. The rest of the rows in the layout file will help you do the same thing with keys of a different size; most backspace keys, for example, are 2u.
You may also be interested in basic layouts. These will allow you to skip much of the hassle of using AutoCAD by placing all the switches in the right position to begin with.
Starting AutoCAD
Go ahead and get AutoCAD, and download any relevant files. When you first start up AutoCAD, you may be met by a bewildering array of options. You'll simply want to open up a new drawing (see image 1). Before anything else, open up the command window (2) and type units (as AutoCAD has autocomplete, you can probably type just "UN" and watch units appear). Since we'll be working in millimeters (sorry Americans!), you'll want to change the units for scale to millimeters (3).
Now open a new tab (4), and find and open the keyswitch layout file (it's default name is plate_components.dwg). We'll be using a this file a lot to copy some designs. Decide on which set of cuts you want to use, and switch tabs back to your first drawing and save it (Ctrl+S, or open the big red 'A' in the corner and navigate to save). Save it as something logical; this file will be used effectively forever.
Layout Editing in AutoCAD
The first thing we'll want to do is edit the key layouts, so you know exactly where every key goes. This is for two reasons; first, given that its a keyboard, the keys are the most important, and second, once you know where the keys go, its easy to design everything around the keys. If you've never used AutoCAD, some of its shortcuts and bindings may be extremely confusing. AutoCAD does have a tutorial available, and Google is always a good place to get answers. Nonetheless (since I started this blog because I was frustrated with the time wasted), I'll try to work through at least the minimum required to 'get' AutoCAD, by walking through my own design.
My keyboard has an extremely odd design inspired by the ErgoDox. It retains the wavy main set of keys and angled thumb keys which made the ErgoDox ergonomic in the first place, but alters the exact height differences between columns and the spacing of the thumb keys to better suit my hands. I actually got this exact spacing by putting my hand on a sheet of paper and tracing bits out with a pen, and then measuring it. I also massively extended the Ergodox to include the keys necessary for a full layout (including making the keyboard in 3 parts), and then some. I'll definitely blog about my keyboard later, but this series isn't really about my keyboard.
I'll assume you already have a good idea how you plan on laying the keyboard out, so we'll need to start by planting some keys. I recommend starting with either the 'J' or the 'F' key (since that's the starting key for your index finger). So we'll first want to copy and paste a single 1u key from the switch layout file to your drawing. Unlike most things,
Autocad isn't click and drag to make a square highlight. If you click one corner, and then move your mouse to the opposite corner and click again, you'll select everything in the region. On the other hand, if you click and drag, you can create custom (non polygonal) regions. Copy and paste commands function as normal; (Ctrl+C) and (Ctrl+V) respectively. You can copy in one tab and paste into another. At first, you'll probably want to snap your first key to the grid lines; this can be
accomplished by choosing to enable grid snapping (5). However, as we are going to be working a lot in fractions of millimeters, you'll probably want to disable it after the first key is laid down. Once you've laid down your first key, you'll lay down the rest in much the same matter, pasting and dragging to the right location.
Before you continue, if you're interested in creating 3D printable files, you'll want to read the section on creating plates, and specifically, the section on converting 2D to 3D in AutoCAD. In order to make the 3D-fying process easier on your computer, you'll have to modify your keys slightly.
Keyboard layouts are (as you can see from mine) pretty much whatever. The main thing is that, for now, you won't want to remove the 19 * 19 square, as it will come in handy later, keys should be aligned to the center (this will matter for 2u keys), and there is a 0.65mm space between each key and the keys around it (the gap I have is not random). When I lay down a key, I'll first enable object snap settings (6). I'll then proceed to draw a line exactly 0.65mm long extending from the corner of the key to the next key I want to add (you can enter a specific line length by hitting tab instead of clicking a given point for the endpoint of your line, and tab again to select the angle if necessary). Then after I paste, I'll select all the objects inside the key and move them (7). Moving works by pressing a point to use as a reference, then clicking the point you want to move to. In my case, I'm going to move the key right up to the edge of the line. Now we have two keys in position! The wavy effect is done by moving the key after by a set amount.
Now you do it again for the next 10 years. Lol just kidding (couldn't resist the Penny Arcade reference). But seriously, you repeat this process a bunch of times until you have the keys you want in the positions you want. If you want to simplify, you can select whole rows or columns and paste/move them. The key to the whole process is to really use the snapping to get nice and accurate spacing.
If you're interested in angling keys the way I have, what you'll want to do is again select the keys/parts of keys you want to angle, then hit rotate (8). Again you'll be forced to pick a point as the pivot; you can either move your mouse around to rotate or press tab again and select an angle. Don't be concerned if this takes a while. I never said this was fast.
Once that's done, there's one more step. We have to scale everything. Select every single item, and go to the command line, and enter 'scale'. What we'll want to do is scale this to a reference. Select a base point, then enter 'r' and press enter. Now, select one of the sides of a 1u keycap (by selecting both endpoints) and then type 19 and hit enter again. I've found the reference switch layouts are slightly large (at about 19.05 or so). The video below details (with voice) all the steps I've taken.
Creating a Plate
Now that we've got the key layouts, we're most of the way there. From now on, you'll definitely want to avoid saving anything over this file, since it's the basis for everything else. From here on out, every file we make will be effectively a laser cutting file. We'll also cover how to convert a 2D file to a 3D printing file here. All these files will be submitted to material processing in order to create the plate and casing.
Fortunately creating a 2D plate is extremely simple and requires no additional knowledge. If you have an idea roughly of what your keyboard is going to look like, all you have to do is figure out how far away from each edge the plate is going to end. You can draw lines from the corners of your keys to demarcate the corners of the plates, then draw lines connecting the corners. After that, you simply need to delete the lines you used to measure distance, and delete the boxes which surround each key, as these boxes are meant to mark where your keycap will land, and should not be cut in the plate. Below is the plate layout I'm using. You'll notice I have circles at the corners; since screws don't usually go through metal, I"ll also need some holes for those. You'll also notice the alignment of everything is extremely strange; this is to save cutting space; although the keyboard is actually quite big, the plates fit in a 2 feet by 1 foot sheet of metal (which incidentally is how big Home Depot sells them). All I did was use a lot of guiding lines and have patience.
Based on what I've read around the Internet, if you don't have access to high precision machining tools of any sort, your best bet for plates is probably to go to a laser cutting shop, which will take CAD files and cut them for you. If you somehow have access to a 3D printer (if you have one at home – which, just saying, makes you f***ing awesome), 3D printing a plate is also an option, although since I'm not an expert I can't say much on the durability of 3D printed plastics.
In any case, there appears to be a consensus that the best way to go about doing this is to have several thin sheets that you stack on top of each other until you have a full keyboard. This is indeed the approach I'm going to use, so I will show you how to use AutoCAD in order to take 2D designs and add depth and export them as 3D printer files.
First, we'll want to change our view from top down (great for 2D) to isometric (better for 3D); right below your tab, there will be something that says[-][top][2D wireframe]. What we want to do is click on the 'top' and convert that to isometric; I'm using South-West Isometric for this one (9). Then we simply type 'extrude' and use this command to extend a 2D object into 3 dimensions (10). Now it is possible that some of your objects will fail to extend (11); if you've used switch cutout 3 like I have, for some reason, the cutouts are drawn as splines (even tho they're completely straight). What you'll want to do is modify all of them to become lines. This is unfortunately a multi-stage process. First, you'll want to convert the splines to polylines. Simply enter 'pedit', and enter 'm' for multiple (12). Then select all your splines and hit enter; AutoCAD will ask if you want to convert your splines to polylines (13). Then select all your polylines and enter 'explode' (14). This will decompose polylines into lines. Unfortunately, since AutoCAD isn't omniscient, when it does this, each 'line' in your image will end up composed of several smaller lines. When you want to extrude, this can cause AutoCAD to crash since it has too many objects to process. An alternative which may save you a lot of headaches down the road is to make sure, when you have your first key, to change all the splines in the key to regular lines, then use that key as the basis for the rest of your keyboard.
Most 3D printers take .stl files, so what you'll want to do is go to the 'Output' tab and select Export, and choose .stl file as the option. Then select the objects you want to go into the file and you're done!
Since I'm using cutouts, this process doesn't really matter to me, so I don't have any images from my build which are 3 dimensional.
Creating the Rest
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Just kidding. Beyond the plate however, the rest of the files proceed in more or less the same fashion. You'll want to decide the dimensions (probably the same as or based on your plate), and draw bunches of lines.
I'll actually take this time to talk a little bit about what I was doing with my keyboard. Since, for about the trillionth time, I have great access to free cutting resources, I knew I was gonna make my keyboard look as classy as possible. I actually have a 2mm ring around my plate which I'm getting cut out of wood, and a wood top case.
The bottom of my keyboard is going to be cut out of a bronze colored sheet of aluminum. The overall effect is from the bottom, you just see a sheet of aluminum, and from the top and sides, you can only see wood (hence why the ring is necessary), so I'm giving the illusion that the entire keyboard case has only two parts. Totally unnecessary, but I think it's pretty cool.
Now that you've finished creating drawing files, it's time to go get your cases. Coming up, we'll talk about the details of wiring and the ever incomprehensible keyboard matrix.
Source: https://npx3.wordpress.com/2016/01/27/how-to-cad-building-a-keyboard-part-3/
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