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Ultimate Homebrewed Cockpit - Pt. 5, The Light at the End Of The Tunnel
By Gene BuckleToe Brakes
Author works on a program
Here is a picture of me while I was working out the NC program to cut the slots for the two potentiometers needed for the toe brakes. The blue object is a MaxNC-10 desktop CNC Mill. It's controlled via the parallel port in the computer next to me. The mill bed and cutter height is adjusted by three stepper motors connected to lead screws. With this machine I can get a cutting accuracy of .00012 which is far greater than I'll probably _ever_ need. :) I'm having to teach myself how to program the machine and it has been a long road. The instructions are simple, you just have to think in three dimensions all the time. Using this machine I'll be able to construct nearly any part I have a drawing for. It will come in very handy when I need to make molds for some of the knobs and such that I don't have examples of. I can cut a "pocket" mold out of aluminum and after spraying a release agent into it, liquid plastic can be poured in to make the final part. With the addition of the 4th axis rotary table, I'll also be able to make knurled shafts, gears, etc.
MaxNC-10 desktop CNC Mill
Here is the mill just beginning its motion to begin the second cut in the toe brake pot mounting plate.
Cutting Slot for the pot mount
The mill is just beginning to cut the slot for the pot mount. The cutter I'm using is a 1/8" diameter three flute end cutter. A "flute" is a cutting surface on the milling bit. They can have from one to six flutes -there may be other configurations but I've not seen any. The work peice is backed by a 1/8" peice of MDF. This is to protect the mill bed from being damaged by the cutter. The cutters themselves are NOT cheap at $6 each. This CNC mill can use any cutter with a 1/8" or smaller shank diameter. The cutters I have for this machine range from the 1/8" cutter used here, down to a 1/8" shank cutter with a 1/32nd cutter on it. While the 1/32nd cutter is VERY tiny, it is going to be of great utility when I start making illuminated button faces. It will be used to cut the lettering into the face of the button. The slot it's currently cutting is being done with a feed rate of 1.5 which means that it will feed the work into the cutter at 1.5 inches per minute.
Toe brake mechanism
This is the nearly completed toe brake mechanism. The two springs will be connected to the original toe brake pushrods to provide the needed tension and return force. 1/16" pushrods will be attached to the toe brake pushrods and will pass through the center of the springs to the slide potentiomters mounted to the metal plate. The metal plate will be mounted at the same height as the pushrods to keep mechanical action perfectly horizontal so no binding occurs. This assembly will be mounted in the bay aft of the cockpit (Bay #5) right where the air conditioning duct for the TEWS racks used to be located.
Wiring
Gettin' wired
This is the first 3000 feet of wiring that will go into the cockpit. I imagine there I'll have to buy at least another 2000 feet before the project is done. I'm using black & red for DC power and white for signal wire.
Test board for EPIC modules
This is the test board for the EPIC modules. Pictured is the first expansion module and the first (of many) 32 point output modules. The first expansion module is on the left. This board supports the 16 analog inputs. These are presented on the 16 slot terminal block located horizontally right underneath the circuit board. Right below that is the switch input matrix. It's an 8x32 matrix and can support 304 switch inputs. The other 48 switches are presented via the four joystick connectors that are mounted on the module circuit board itself. The board to the right is the 32 point output module. I can utilize up to four of these per EPIC card. This module will allow me to not only control indicators, but anything that requires a signal to start. I'll be able to use this to control things like stepper motors, solenoids, etc. This module or one like it will also be used to control a Radio Shack recording chip. I'll be loading a few of these chips with real F-15 cockpit voice announcer messages and the 32 point output module will control which one gets played back at any given time.
Flight Stick
Stick force sensor box
This is the nearly completed Stick Force Sensor box and flight grip. It was discovered shortly after this picture was taken that I'd gone off and built the damn thing backwards. It has since been corrected. :) The grip is the correct style (B8) for the F-15C, but it's actually a NOS (New, Old Stock) grip from an F-86 Sabre. I'll be replacing the wiring to the original plug with a smaller gauge wire that's easier to work with than the 16ga wire that it has now. The wiring harness that plugs into the SFS box will also be replaced since I can't obtain replacement cannon plugs to mate to the originals that are there now. I'm going to build another SFS box that will utilize the Suncom F-15 flight grip. This will also easy interchangeability so I can go from a C model to a modifed E model at will. The cockpit instrumentation will be interchangeable as well.
Suncom F-15 Joystick Internals
This is what the interior electronics of the Suncom F-15 stick look like. I'll have to replace the circuit board with one I can more easily work with, but I have take special care to make sure the tiny micro pushbutton switches remain in the same place as on the original circuit board.
Ejection Seat
Ejection seat construction
Here is the beginnings of the first Ejection Seat. The seat itself is being constructed based upon Chris Van Lierop's F-16 ACES II seat plans. We're waiting on final dimensions from a real F-15 ACES II to begin construction on the lower portion of the seat. It won't be 100% accurate, but it'll be damn close. The gray peice of metal you see on the headrest is the pitot tube assembly from the ACES II head peice I have.
Bass speakers for immersion
This is one of two bass shakers that will be installed in the ejection seat. This will provide a great deal of immersion by way of impacts and vibration feedback. These units can be obtained in pairs for $45 from American Science and Surplus. (Google for it.) As always, if you have any questions on the cockpit or would like to let me know what you think, I can be reached at [email protected]. If you'd like to build your own cockpit, please head over to http://www.simpits.org! Check it out and join the mailing list. There are a lot of knowledgeable folks on the list building everything from an F-16 to a 747. See you next time!
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