Archive for the ‘Roll Servo’ Category

A Day of Redo – 4 hrs

December 25, 2011 Leave a comment

Sunday Dec 25, 2011

Merry Christmas! We had family at our home yesterday so today was actually quiet around the house after church and I had a few hours to work on the project after lunch. To prepare for assembling the wings to the fuselage I turned the fuselage cradle around so the tail is facing outward. There is just enough room to put both wings on in this position in the three car garage.

But most of today was about redoing a couple of things I should have done right the first time. Two days ago I started removing the landing gear weldments to file out the holes for the main wing bolts. Today I finished that job by removing, filing, and replacing the right weldment. I hate redoing something I should have done right the first time.

Then I marked the bottom skins of the wings as instructed in the plans. Sorry about the bad picture but in the image you can see horizontal lines from the open hole going outboard and I put tick marks at 3 and 4 inches outboard along those horizontal lines. The idea is to be able to drill through the bottom fuselage skin and hit these holes later, or at least get pretty close to centering on these holes.

The other redo today was to remove the right wing aileron bellcrank and grease the bushing. I forgot to grease it when I put the aileron servo in so out it came. I also took the opportunity to trim the bushing slightly because I had too much free play before and the bellcrank would go “clunk” when I would slide it along the bushing. Now the gap is small enough that you can just barely hear it click if you slide it. Of course the roll autopilot servo is mounted to that bellcrank so it came out with the bracket. Fortunately, I did not have to remove the safety wire.

Started Riveting Right Outboard Bottom Skin – 2.5 hrs

December 21, 2011 Leave a comment

Wednesday Dec 21, 2011

First topic today is a little clean-up task. When I installed the dynon pitot tube I mated the spade connectors that hook the pitot tube to the heater control unit. Afterward I realized I should have put a small piece of shrink sleeving on each one just as insurance that they can’t work themselves loose over the years of vibration. So today I demated each connector and installed that shrink sleeving. Here is a picture that shows you what I mean.

On a more major note I started installing riveting the outboard bottom skin onto the right wing today. Jennifer helped me with eight extra tough rivets but the rest I did solo. It would be faster if I had more help but Jennifer was only available for a few minutes. In spite of that I was able to make progress by myself. It’s getting a little easier because I am learning the best contorted position to get into for each rivet and I am getting to where I can pretty much tell by feel if each rivet is good when I set it. I inspect the shop heads of every rivet but I can now set two or three in a row as a group and inspect them as a group and that saves time compared to inspecting each head immediately after setting it.

I also did some work on the fuel vent line on the co-pilot’s side of the forward fuselage. This one is 90% done now if I don’t mess it up on the last bend and flair.

Right Wing Ready to Close – 1 hr

December 15, 2011 Leave a comment

Thursday Dec 15, 2011

The photo below may not look too different than the one yesterday but now the roll servo wiring is completely tidy all the way out to the wing root, dust is vacuumed out, and screws are all torqued and striped. I also rearranged the bolt on the bellcrank for the servo linkage so the lock nut is facing out where it will be easier to inspect. This wing is officially ready to close so I will begin the process of riveting the bottom skins on.

Here is a view of the wiring as it routes from the bay where the motor is located through the next inboard bay.

Categories: Roll Servo, Wings

Wired Up Roll Servo – 2 hrs

December 14, 2011 Leave a comment

Wednesday Dec 14, 2011

The task tonight was to wire up the Dynon autopilot roll servo motor in the right wing in preparation for riveting on the bottom skins because it’s easier to do this wiring with the bottom skins off. The Dynon instructions say to twist the green and blue wires which carry digital serial commands from the Skyview network so that’s the first thing I did. I stripped the end of the motor wires and crimped D-sub pin contacts onto the wires. I put a couple of pieces of shrink tubing over the wires and inserted the pins into a 9-pin connector shell. One of my main objectives was to route and secure these wires such that I will never have to worry about them getting entangled with the aileron bellcrank. That would not be good. So I installed a new snap bushing in the inboard wing rib close to the top skin so the wires would not have to route under the bellcrank at all. Then I installed two Adel clamps; one on the outboard wing rib and the other under one of the screws that holds the bellcrank down to the spar (I substituted a slightly longer screw there to make up for the extra thickness of the Adel clamp and a washer). Finally, I added two adhesive wire tie mounts for secondary support of the connectors. In the photo you can see the routing. I started to use backshells on the connectors but I decided they don’t add anything except extra weight which is not helpful. I secured the two connector shells together using zip ties. I’m not sure this is conventional but in some ways it’s better than jackscrews – the zip ties can’t loosen and fall out in time due to vibration. I think this setup meets my objectives.

Categories: Roll Servo, Wings

Miscellaneous Chores – 2 hrs

November 24, 2011 Leave a comment

Thursday Nov 24, 2011

Happy Thanksgiving! This morning I was able to get out into the garage early for a couple of hours before the activity started to get ready for our Thanksgiving get-together. I was hoping I could quickly install safety wire on the roll servo motor bolts but it took me five tries to get it good enough to be satisfied with. This one was tricky. It’s still not perfect but I am satisfied it will do the job.

Then I made a little clip to support the Tee in the static line on the F-708 bulkhead.┬áThis will keep the T from working it’s way loose from the static line under vibration. I made it from .020 thick Alclad sheet and secured it to the bulkhead with one LP4-3 rivet. The screw and the lock nut came with the Tee in the SafeAir1 kit.

Then I made several more clips to hold the static line to the back of the F-706 bulkhead in route to the ADAHRS unit. Here you can see two of the clips installed with clecos. I will rivet the clips later with flush head rivets on the forward side of the bulkhead. I stopped here because I am uncertain about the routing from here. I will either route it down the center rib with the pitot and AOA lines or I will route it along the nearest J-stringer.

Finally I installed a piece of plastic conduit in the aft fuselage through which I plan to route the electrical wiring to the tail; namely the strobe on the rudder. This view is from the F-706 to the F-707 bulkhead.

This is from the F-708 to F-710 bulkhead.

Fuel Pump Cover, Static Lines, Roll AP Servo – 5 hrs

November 23, 2011 Leave a comment

Wednesday Nov 23, 2011

With my recent success designing and fabricating an ADAHRS mount from scratch I felt confident enough to start fabricating the fuel pump cover today. I designed this over the last few days and I bought the raw materials last weekend at Aircraft Spruce. The first part was the center cover which is cut and folded from 0.020 thick Alclad sheet. Here is a picture of my custom cover next to the Vans stock fuel pump cover. You’ll see how this works in a minute.

In this photo you can see the side covers laid out on the .020 sheet material ready for cutting.

Here the side covers are assembled to the center cover with clecos. It doesn’t look too bad so far.

This is how it will mate to the fuel valve cover. I need to make a new fuel valve mounting plate with an upper extension for the trim cable mount that is rectangular and angled at 60 degrees to sit flush against those three flanges but I don’t have the .062 stock right now. My aircraft is a bit unusual in that I am combining fuel injection and manual elevator trim. I seems that most people go with the electric elevator trim but I really like the manual trim knob for the feel and resolution it provides. What I like about this fuel pump cover design is it will fully enclose the elevator trim cable.

I placed it in the cabin just to get an idea if it was going to fit the way I hope it will. It needs some angle pieces to attach it to the F-782 cover but it looks promising. I wish I had that .062 stock.

I shifted gears over to the static ports again because the ProSeal was pretty well set after three days. I removed the tape and here is how the ports look on the inside.

Routing the tubing was pretty simple. I used one T to split a single line into two, one going to each port. I also made four little clips out of .020 alcald stock to hold the static line to the main longeron. You can see one in this picture.

I ran the line up to the F-706 bulkhead where it will turn upward to go to the future ADAHRS on my new custom mounting bracket. Here you can see the little clips that guide the tubing and keep it from flopping around.

The next topic is the installation of the Dynon roll servo actuator for the autopilot in the right wing. I need to get this done soon because it is just about time to mate the wings to the fuselage and drill the aft spar attachment. The first step was to remove the bellcrank and drill a hole for the servo linkage. It’s the middle 3/16 diameter hole in this view.

Then I replaced the stock bellcrank bracket with the Dynon-specific bracket which also supports the servo motor. That includes two cadmium plated parts you see in this view.

Then I installed the motor and secured it with three AN3 bolts and washers. I torqued the bellcrank support bracket bolts and marked them with torque seal. I still need to safety wire the three bolts that hold the motor.

My last task today was to assemble the servo linkage with two rod end bearings and set the distance between the two rod end centers to 5.00 inches. I torqued the nuts but I will probably also stake these with epoxy.