Here’s some pictures showing the test fitting of the new SFS box.
There are only two issues with this setup – the range of motion for the stick is far too great. This can be cured with a little “motion restriction plate” which would be just a sheet of material with a square cut out of the center and placed at the stick base. The second issue is that the springs in the gimbal are not strong enough to keep the stick centered.
The SFS box & grip really aren’t that heavy, but the account for a huge amount of force at the end of the stick gimbal mount. Hopefully a new set of springs can cure this without too much bother.
In order to have space for wiring and power supplies, I decided to add a forward deck to the cockpit ahead of the instrument panel:
There are two of these support assemblies. Each one is made of two side ribs with “expanded” stringer notches, a single cross-piece and two doubler plates. It’s assembled with six #10-24 screws on each side and the screws go into #10 T-nuts. I’ll be making the drawings for these parts available to those that have purchased the project CD.
The deck itself is made of two pieces. Each one is notched to accommodate the center rib as you can see in the photo. The deck itself is just slightly higher than the instrument panel and a stiffening brace can be installed between the panel and the deck support if you feel the need.
The grip I’m using for this cockpit is a rebuilt Suncom SFS F-15 Eagle grip. In order to mount it to the 3/4″ EMT mounting post in the SFS box, I needed to attach a 3/4″ female EMT pipe fitting to the grip base.
I used a “steel epoxy” called JB Weld to ensure that the joint would be secure. The fitting is mounted in the outside half of the grip. By attaching it to half of the grip, I’ll be able to tear the grip down for maintenance if needed.
I was also able to get the edge-lit panel machined for the left sub-panel in the cockpit. Here’s a picture of it right off the ‘bot:
The stock material is .25″ P95 translucent white acrylic. I chose this because of it’s amazing light diffusing properties. The pocket in the panel is .20″ deep, leaving me about .05″ of material left.
The next steps will involve creating an alignment jig for the laser and then the switch holes will be cut, the panel will be painted and then it will be lettered.
Finally, here’s a short video of the progress so far:
Today I was able to get the main instrument panel cut out. It turned out really nice.
The whole point of the panel is to get it installed!
The panel has cutouts for a left & right sub-panel, a 15″ LCD PFD display, side bars for Garmin G1000 compatible controls and a button bar on the bottom.
The LCD has a smoked acrylic cover on it – the flash illuminates the LCD frame behind this cover. You can’t see it under normal lighting conditions.
Here you can see a bit of how the custom LCD panel carrier is mounted into the instrument panel. I’m really happy with how this turned out and with any luck I’ll be able to get the left sub-panel wired up and get its edge-lit panel created tomorrow.
Yesterday I was able to get the metal parts for the left sub-panel cut out.
Because I only have one .125″ cutter left, I needed to go very slowly and take very small “bites” out of the material. The panel is 6061-T6 aluminum, 0.062″ thick. At the feed rate I used and taking .01″ per pass, it took four hours and forty-six minutes to cut.
Here’s the result of all that time:
I installed the “starter” push-button into the panel to see how it would fit with the test engraving of the light plate that I did. The test light plate is made of card stock that I engraved on the Mini-24. Below is a close up of the engraving.
It’s kind of hard to see in this picture, but the result is very nice.
The three rectangular cutouts at the top are for the landing gear indicators.
I decided when I finished my cockpit, I was going to call it an Me-109F/X. This way I could get away with filling the panel with modern goodies.
This includes a glass cockpit display. In order to do this, I needed to rebuild an existing 15″ LCD panel so it would mount properly in the space I had available in the instrument panel. Below is the result of that reconstruction
I move the panel components to a custom fabricated 1/8″ acrylic mounting bracket.
Here’s what it looks like showing a screen from a Garmin G1000 emulator that a friend of mine is working on:
I’m currently finalizing the layout of the instrument panel. When it’s complete I’ll make sure to get pictures posted.
Most fighter aircraft don’t have seats that move fore & aft like a car seat does. Instead, the seat is bolted in to place and the rudder pedal assembly is built to move in order to adjust for different sized pilots.
In order to do that in my cockpit, I mounted my rudder pedals on a pair of ball bearing drawer slides laid horizontally.
The drawer slides are a little bit over 12″ long.
In order to “lock” the rudder pedals into place, I installed a pair of aluminum plates into the cockpit floor that are drilled to take 1/4″ locking “pins”.
It’s pretty simple, but it does get the job done! At some point I’d like to be able to turn the two bolts I’m using as locking pins into actual pins that can be retracted from the cockpit itself, allowing adjustment without having to exit the cockpit and manipulate them from the front access hatch.
The other project that was finished is the trim & flap wheels:
The wheels have a 12 tooth sprocket and they drive a 48 tooth sprocket that’s connected to a potentiometer. This gives roughly four turns of the wheel to one turn of the pot.
I’m using #25 roller chain for this. It’s similar to bicycle chain, but about half size. The 48 tooth sprockets have travel restricting devices installed in order to prevent the high-torque output of the trim wheel from destroying the end stops in the potentiometers.
Here’s a pic of it installed in the prototype:
It shouldn’t be too much longer before I actually get to flight test all this stuff. *laughs*
Well here’s the completed throttle quadrant. I’m happy with how it turned out – which is surprisingly good considering how much I suck at metalworking.
I’m using a standard DE9 connector for the three slide pots that are linked to each lever arm.
Right after I finished the throttle quadrant, I decided it was time to address the shortcomings in the rudder pedals that I built last summer. I was very disappointed in both the toe brake mechanism as well as the size of the pedals. I got lucky and found a pair of gas springs that had a 1-7/8″ stroke with a 40lb compression force. They were surplus and ran me a whopping $1.99 each.
Here’s a comparison between the new pedal design and the old one. The new pedal is on the right.
The pedal design is based on a set of CAD drawings I found on the ‘net, drawn by a gent that goes by the nick Baloo. The CAD drawings were entirely metric, which doesn’t do me much good here – I don’t dare mix measurement systems because I know for a fact it’ll come back and bite me in the ass some day. I drew a new pedal design based on Baloo’s original drawing, but I increased the pedal length by about 1/2″. They’re just about 12″ long now. The pedals were cut from 1/2″ Baltic Birch, which is a 7+ layer high quality plywood.
Here you can see the new gas spring setup. The 40lb force required to actuate the gas spring gives a very realistic brake feel to the pedal. I was very happy with the result. I was also able to re-use the toe brake pots and actuator hardware without any changes.
Pictures are worth 1000 words:
Now that all the parts are cut and everything fits like it should, It’s time to move on to getting this thing assembled!
I made one more change to the original BRFS design:
Instead of using the recommended method for keeping the main support bolt from rotating when you tighten or loosen the friction knob, I installed a stove carriage bolt that has a squared area right underneath the bolt head. This prevents the bolt from turning once it’s drawn completely into the material.
The first step is to get each lever rigged up:
The rigging line I used was 36 strand steel beading wire. This and the swag collars can be had at your local craft store.
I’m using a pull-pull system to actuate the slide pot – the geometry is similar to the BRFS throttle, but because my levers are symmetrical, I didn’t need to use the spring to keep tension on the line. I’ve also drilled two holes (only one is used) to attach the pull wires to the pot arm. Each hole that the rigging wire passes through has been carefully de-burred in order to make sure that no sharp edges existed that could cut the line over time.
This is what it looks like from the bottom with all three lever assemblies installed.
The knobs are painted and they turned out really nice!
(don’t forget to click the “more” link below!)
This is how the lever arms in the throttle quadrant operate: