UPDATE (9/1/2014): If you are looking to build a project like this, see my post on the Rabbit Engineering Model I1 device.
Lately I have been on a Strike Fighters 2 binge. SF2 is a great indie combat flight sim, written by Tsuyoshi “TK” Kawahito (a flight sim developer rock star from the 1990s) out of his garage, and sold DRM-free online. The game presents air combat between the 50s and 80s, and is in the tradition of the old ‘survey sims’ of the 1980s and 90s. It has a solid user community, with lots of free add-ons available.
As with a lot of older flight sims, there are a lot of keyboard commands. Frankly, looking at your keyboard while you fly breaks presence for me. This is the reason why people buy HOTAS controllers, after all. But of course, you can’t get all your controls into a HOTAS setup. For commercial flight simulators (like FSX), there are many dedicated controllers like Saitek‘s Multi Panel or Radio Panel, but there is really nothing comparable for combat sims.
So time to build a set of custom controllers for SF2. I realized that part of the coolness of the Saitek controllers was that they look like the real thing. So I did a little research into combat aircraft panels from that era. Here are two representative ones:
This is part of the defense panel from an F-4. Black panel, white line breaking up the controls into groups.
This is part of the input panel from an A-6’s DIANE computer. Again, black with white sans-serif text, and again big, chunky controls (to be usable while wearing flight gloves). In general, everything is kind of lumped together, but grouped using text and likes on the panel. So this was the look I would try to reproduce in my panel. On top of that, I wanted to keep the entire project cost under $100 (the cost of a typical Saitek panel), and it had to be easy to setup/teardown on my desk. Finally, it had to be plug-and-play; no messing with software, loading profiles or calibrating anything. It would use the IPac2 Distribution box to interface to the PC.
I decided that the controls I would build would be an armament panel, radar control panel, and some miscellaneous controls (gear, flaps, etc). The idea was to cover as many of the common aircraft functions as possible between HOTAS and these new panels; sim-only controls (such as time compress, the map and radio controls) could remain on the keyboard.
The project: Custom controllers for Strike Fighters 2
Because this project was intended to have a clean look, planning was more important than ever. I began thinking about how many game functions to map onto the 32 available inputs, and on what type of physical control to surface them (rotaries, buttons or toggles).
Once that was cleared and I had the count of how many of each count I needed, I bought them at Jameco. I then carefully measure each one to plan the layout on the 5″ enclosures:
Picking your parts early is important so that you can measure and lay things out correctly.I began by choosing a good box – ABS plastic, basically 5″x5″, which I found at Skycraft Parts & Surplus. I also used three types of control (bought them all at Mouser):
- Rotary pulse switches, which allow a different input for clockwise and counter-clockwise turns (with suitable knobs).
- SPST Pushbuttons [OFF-(ON]
- SPDT toggles [(ON) – OFF – (ON)], which return to center, and give you a different input when pushing up or down
In order to plan the layout, I would need something more accurate than my chicken scratchings. I used Scribus (an open source page layout editor) to do an accurate plan which I could print at 1:1 scale. Because the plan is digital, you can play with many arrangements and think about how things will work together without risking any materials or parts. In the end I finished with this arrangement:
A huge advantage of using page layout software like Scribus is that you can print out the layout and use it directly as a template to drill with etc. Once the layout was finalized, it was time to create a ‘decal ready’ version:
This version was then printed onto decal inkjet paper, overlaid with a transparent, self-adhesive film to protect it from spills etc, and then stuck directly onto the enclosures. Here they are ready to drill:
Now we drill. The different controls required different size holes (which are measured from the electrical parts directly). The most interesting were the buttons, which needed a half inch hole (12.7mm). To do this in plastic, you need to use a spade bit, which is a mean looking implement:
When it is done with the hole, the spade bit leaves behind this amusing looking wormy thing:
Although my bits were new and sharp, they dis leave a slightly ragged edge on the decal. This is not really a problem, as each control has some form of lip which covers this up later.
Now that all the holes are drilled, you can attach the controls themselves, in preparation for soldering.
Attaching the controls is fairly straight forward – screw them into place. Be careful in tightening them though, as most buttons/pots have either plastic or aluminium threading, which will pop easily under a lot of force (and then you are stuck with a button/pot you can’t use). Once they are all in, solder all the common poles together in series, and then put one cable to each control. Buttons get single cable, but the rotary switches and toggles get two apiece. I used a ribbon cable from a (very) old 3″ floppy disk. These cables are compact and solder quite well, so work nicely for this kind of project. Here is one completed:
Notice that the back of the box (black bit above) has had a rectangular slot cut out (with Dremel) to allow the ribbon cable to pass through. I then capped the cable off with a DB9 plug, so that I could plug into my IPac 2 distribution box. Due to the number of controls in a box, each of them had two DB9s wired up. To finish off, I added two strips of self-adhesive non-slip rubber tape to the bottom of each box (I had this left over form an automotive project). This prevents it from moving around the table as you use them, and also allows the ribbon cables to pass under the controls. Here they are ready to test:
Now for the setup. I plugged them into the distribution box. Quite pluggy:
I then fired up the IPac programming utility and set it up. Because the IPac 2 has flash memory, it keeps its programming even without power. That means I don’t have to re-program each time – just plug and fly.
This is how it is positioned – between the throttle and keyboard. Notice that The ribbon cables of the box closer the the desk edge pass under the other box, and up to the distribution box. This is another advantage of using ribbon cables instead of bundles.
Testing went very well – after entering the new key bindings into Strike Fighters 2, I was off blowing things up. The chunky buttons and switches really fit with the level of technology presented in teh game. Having the rotary switches especially makes for a very nice experience for things like radar mode and range. This project cost about $40 for the control panels (the rotary switches are a little expensive – you can save probably $15 by using toggles instead), and about $50 for the distribution box (which includes the price of the IPac). Well worth it, especially given there is nothing like it to buy off the shelf. And of course, you can use this for any sim that takes keyboard inputs (including the old classics for DOS, if you are running them inside DosBox in Windows).