I guess four days traveling in the airplane didn't fill me up! Since I had planned a weather contingency day into my schedule, my Outlook calender showd me with no plans at the office today, so I figured I'd play hooky and get to work on the AlTrak installation. I'd gone over it many times in my head, and I pretty much had it figured out - but still only got about 80% done in a ten-hour workday. Of course, I was doing an oil change and FWF inspection in the morning as well....
I'm done except for installing and wiring the light/switch on the panel and hooking up the power. I went with Stein's suggestion of mounting the little bitty "brain box" back near the servo, and he was right - it makes the wiring and installation easier! A few notes:
1) Replacing the elevator bellcrank mount took about an hour (after a half hour of disassembling the baggage compartment and removing the battery and battery tray/relay assembly). I decided to replace the rivets with #8 screws and locknuts, as it would be awfully tough to re-rivet the things. If you are building, and there is even the most remote possibility you'll add a pitch servo - scar for it now!
2) One advantage to doing screws was that drilling the holes was easier. After drillign out the old mounts, I held them together, and the holes matched really, really close, so I used them as drill templates (right on left, left on right) for the new mounts. I just cleco-clamped them together, drilled two holes, put in clecoes, then drilled the rest. Once I had them clecoed in the airplane, I match-drilled the holes to final size for the screws - worked great! I used countersunk screws under the servo, as it looked like pan-heads would interfere. I thought getting the nuts on would be tough, but it wasn't too bad - just a few hand cramps!
3) The drawings give good dimensions for drilling the hole to mount the new pushrod, but they are vague on mounting hardware, washers etc. Everything you need comes with the kit, but they assume that if you've built an airplane, you know enough to figure out how the little bits should go together. If you're doing this early in your own build, you might want to look at someone's installation to see where capture washers go. It all set up real nice, and is not even close to an over-center situation. I was also impressed that, like the aileron servo, you can't feel any drag when it is powered off. Seems like you would, when you move the servo arm by hand, but I guess leverage plays into it.
4) I mounted the brain box on the fuselage bulkhead, facing aft. this made the wiring very easy, and access is good (just remove the baggage compartment). During checkout, they tell you to move it by hand to make sure things are moving in the right directions, and this location makes it easy to unscrew and do that.
5) I ran my wiring alongside the static lines - up the left side under the main longeron until the flap actuator compartment, then down under the fixed floor (I rivetted mine per plans), then through the main spar with some other wiring. Sounds easy - it wasn't! That took about three hours. Still, it was a lot less than it would have been to put nutplates in for those aft floors, and remove all those screws....Hey, everyone makes up their own mind on that one! I found that a piece of 040 safety wire makes a pretty good wire "snake" - just use mirrors and flashlights to help guide it through each part in turn. My wiring only has five conductors going forward to the light, plus one for power. The five are in a cable, and that was fine, until I got to the spar. I just couldn't get the cable to go through the opening I had, so I slit open the last six inches, and fished the conductors through one at time, then was able to pull the rest of the cable through. I quit for the night with it in the left gear tower. Next work session, I'll pull the panel and finish up.
6) This was the first time I'd had the forward floor and baggage compartment out since the DAR inspection last Ocober, and with 150 hours on it, I figured it was a good time to do a mini-inspection. No suprises - no wear point,s all wires still secured, and all control fasteners still like they were when Mel looked them over.
I'm looking forward to finishing this thing up some evening this week, and giving it a try! It really was fun to be doign some building and fabricatign again (but really nice to know that the airplane is still flyable!) The biggest design problem I had was figuring out where to put the button on the panel...I guess the compass correction card is going to have to find a different home...
I hate having my plane in an "unflyable" condition - it just makes me nervous knowing that I can't go get a flying fix - so I worked hard to get the interior back together and the new wires coiled up neatly before I left for the night. I could fly it in the morning if I wanted...nah - gotta go to work sometime!
Paul
I'm done except for installing and wiring the light/switch on the panel and hooking up the power. I went with Stein's suggestion of mounting the little bitty "brain box" back near the servo, and he was right - it makes the wiring and installation easier! A few notes:
1) Replacing the elevator bellcrank mount took about an hour (after a half hour of disassembling the baggage compartment and removing the battery and battery tray/relay assembly). I decided to replace the rivets with #8 screws and locknuts, as it would be awfully tough to re-rivet the things. If you are building, and there is even the most remote possibility you'll add a pitch servo - scar for it now!
2) One advantage to doing screws was that drilling the holes was easier. After drillign out the old mounts, I held them together, and the holes matched really, really close, so I used them as drill templates (right on left, left on right) for the new mounts. I just cleco-clamped them together, drilled two holes, put in clecoes, then drilled the rest. Once I had them clecoed in the airplane, I match-drilled the holes to final size for the screws - worked great! I used countersunk screws under the servo, as it looked like pan-heads would interfere. I thought getting the nuts on would be tough, but it wasn't too bad - just a few hand cramps!
3) The drawings give good dimensions for drilling the hole to mount the new pushrod, but they are vague on mounting hardware, washers etc. Everything you need comes with the kit, but they assume that if you've built an airplane, you know enough to figure out how the little bits should go together. If you're doing this early in your own build, you might want to look at someone's installation to see where capture washers go. It all set up real nice, and is not even close to an over-center situation. I was also impressed that, like the aileron servo, you can't feel any drag when it is powered off. Seems like you would, when you move the servo arm by hand, but I guess leverage plays into it.
4) I mounted the brain box on the fuselage bulkhead, facing aft. this made the wiring very easy, and access is good (just remove the baggage compartment). During checkout, they tell you to move it by hand to make sure things are moving in the right directions, and this location makes it easy to unscrew and do that.
5) I ran my wiring alongside the static lines - up the left side under the main longeron until the flap actuator compartment, then down under the fixed floor (I rivetted mine per plans), then through the main spar with some other wiring. Sounds easy - it wasn't! That took about three hours. Still, it was a lot less than it would have been to put nutplates in for those aft floors, and remove all those screws....Hey, everyone makes up their own mind on that one! I found that a piece of 040 safety wire makes a pretty good wire "snake" - just use mirrors and flashlights to help guide it through each part in turn. My wiring only has five conductors going forward to the light, plus one for power. The five are in a cable, and that was fine, until I got to the spar. I just couldn't get the cable to go through the opening I had, so I slit open the last six inches, and fished the conductors through one at time, then was able to pull the rest of the cable through. I quit for the night with it in the left gear tower. Next work session, I'll pull the panel and finish up.
6) This was the first time I'd had the forward floor and baggage compartment out since the DAR inspection last Ocober, and with 150 hours on it, I figured it was a good time to do a mini-inspection. No suprises - no wear point,s all wires still secured, and all control fasteners still like they were when Mel looked them over.
I'm looking forward to finishing this thing up some evening this week, and giving it a try! It really was fun to be doign some building and fabricatign again (but really nice to know that the airplane is still flyable!) The biggest design problem I had was figuring out where to put the button on the panel...I guess the compass correction card is going to have to find a different home...
I hate having my plane in an "unflyable" condition - it just makes me nervous knowing that I can't go get a flying fix - so I worked hard to get the interior back together and the new wires coiled up neatly before I left for the night. I could fly it in the morning if I wanted...nah - gotta go to work sometime!
Paul
