Mar 02, 2024     roll servo rigged - (4 hours)       Category: Controls

The Garmin g3x manual calls has instructions that are important for this operation.
The heim jones on the pushrod must have .375 minimum thread engagement
The servo arm should be 90 degrees to the pushrod when the ailerons are centered
For best performance the angular travel of the arm should be maximized to the extent possible while still ensuring the ailerons hit their mechanical stops before the servo arm hits the over center stops integral to the face of the servo.

Taking these considerations in order; The pushrod doesn't have witness holes to indicate minimum thread engagement, so I measured them. The threaded portion is .75, so what this is saying is that they need to be 1/2 way screwed in at a minimum after their final adjustment.

I set them up to utilize the center hole of the lever arm as a starting point and with everything rigged I have exactly 1/2" thread engagement, or effectively twice the required minimum. With the jam nuts taking up another 1/8", theres no way that this can unscrew itself enough to become disengaged so this meets the standard aircraft convention for pushrods.

When run through the entire range of motion, the system is hitting the aileron hard stops before the servo lever touches the over center bracket with about 1/4" to spare. I believe I've got margin on both the over center bracket and pushrod thread engagement to move this to the outer servo lever hole for maximum travel per the Garmin instruction if the roll reaction is to twitchy, but this is set up sort of middle of the road right now and I'm going to try it out this way first.

  Feb 27, 2024     Aileron system review. - (8 hours) Category: Controls

I've spend the last couple of days tweaking with the aileron system.

I thought I had the aileron system pretty well rung out, but while I was under the right wing manipulating this back and forth, I noticed an ever so slight rubbing sound at full left aileron deflection. It sounded like a wire rubbing so I started with a visual inspection of the wire bundle where it went into the roll servo, but that was well secured and out of the way.

It took a while to chase this down, but eventually I discovered that at full deflection, the outboard right aileron hinge was just ever so slightly rubbing against a rivet tail on the aileron bracket. I changed teh washer stackup to move the aileron inboard the width of 1 washer, which is about .060 and that cleared the rubbing. I may give this another look later and see if I want to move both ailerons inboard another .060. That will leave me with about a 3/16 gap between the ailerons and flaps, while the plans call for .25.

That doesn't seem like enough to negatively affect anything and I sure don't want there to be any possibility whatsoever of the ailerons rubbing on anything. An alternative may be to make sure the offending rivet tail is set correctly and not sitting proud. I'll revisit this later.

  Feb 23, 2024     Installed and rigged ailerons - (9 hours)       Category: Controls

This was one of "those" days. Nothing bad happened, but nonetheless I felt like I was swimming upstream all day long.

I installed the H/S yesterday with bolts just snugged down but not torqued. When I got to the hangar this morning with the idea that I would install the vertical the same way and then start working on fitting the empennage fairings.

All of my flight controls are wrapped in blankets and stacked up in the hangar and the ailerons were on top of the vertical stab, so for no other reason than that I decided to mount and rig the ailerons first. I expected that its would take a couple of hours and then I would get on to the empennage.

Well first of all, I originally rigged these in the garage when I first mounted the wings. The bellcrank to aileron pushrods were the ones I inherited with the wing kit, and they had the rivet tails squashed over. I had rigged everything with them, but then I ordered and fabricated new ones.

Now I carefully measured the old ones, then took the helm joints off them to transfer over to the new ones. I then started hanging the left aileron, and realized that the piece of tape on the wing where I had sketched out the correct washer stackup had disappeared sometime in the last year and a half.

I was playing with this when my hangar neighbor Ron Hart came over and he helped me for a while. Eventually we got it figured out. After that one, I thought to check my build log online, and sure enough, I had captured that data in an entry with pictures, specifically so it would be easier to put this back together.

Based on that, it only took a few minutes to hang the next one.

I thought that I had the new pushrods the exact same length as the olds ones, but something wasn't right. When I pinned them with the stick straight and one aileron neutral, the other one was up about 1/4" at the trailing edge. Not cool.

I took the pushrods out again and decided to start from ground zero. I knew that the stick to bell crank pushrods hadn't changed, so I reasoned that if I fixed the bell crank in the proper neutral position with the rigging fixture I could then adjust teh smaller aileron pushrod correctly.

In trying to install the tooling fixture and small pushrod in the bell crank, I managed to drop the bolt. When it hit, I knew it was in trouble, because instead of the think that a bolt makes when it falls to its final home, this made more of a looney tunes sound o something bouncing around like. a plinko ball that going to end up who knows where.

I stuck my arm up to the shoulder in the wing feeling around in the various bays and didn't feel it, so out came the flashlight and mirror. No joy. Then the the camera on my phone from every conceivable angle. Where the heck is that thing??? I thought maybe it had fallen out of the wing after all and looked all around the floor, I even looked in my shirt pockets. I spent, no joke, over an hour looking for that freaking thing.

After all that, I finally discovered that it had bounced one bay over, ricocheted off of who knows what, and fallen down into the pitot mast. I was able to retrieve it with a magnet.

Once that was sorted, it was pretty easy to zero out the ailerons and then reinstall all the associated bushings, washers etc.

As far as control travel, I have the per print hard stops but somebody on VAF has pointed out that a 1" delrin washer/bushing over the aluminum bushing on the pushrod bracket attach at the aileron will land a little softer the it hits the stop. I had previously sorted these, and I installed them now as part of this rigging process.

What happens is that when the aileron goes up, this bushing hits the bearing support bracket slightly before the other leg of the aileron hinge bracket hits the hard stop riveted on the side of the same bearing support.

The hard stops are installed so that they will limit control travel very close to the max allowable throws (up 30* down 17*). while the delrin block pulls that back more toward the lower end of the range. After this was all together, I checked throws with a digital inclinometer and got an average of 26.6* up and about 15.5* down.

Torqued everything that I touched today as unless something unexpected comes up these won't need to come apart again.

Attis point, the only thing left on the aileron system is securing the pushrod bolt thru the bottom of the left stick (I was short one specialty washer and have ordered more from vans) and teh final length adjustment of the roll servo pushrod.

It's good to have all this done, but it sure seem slick it shouldn't have taken a full day to get it accomplished!

  Feb 21, 2023     Engine control cables - (4 hours)       Category: Controls

Installed the throttle mixture and prop cables. It took while to figure out a routing that wouldn't interfere with anything else, especially for the mixture due to tree way it has to snake in from of the oil cooler.

Strategically placed adel clamps on the engine mount give the cables some support while still allowing them to flex with engine movement.

I'm starting work on the bell crank for the mixture, but I don't have the right hardware so it will just be a temporary install for fitment at this point.

  Sep 24, 2022     aileron hardware stackup reference - (1 hour)       Category: Controls

This entry is just a reference for the hardware stackup I ended up with at the aileron hinges. This washer orientation provides the perfect 1/4" clearance with ailerons neutral and flaps retracted, per print.

  Sep 30, 2021     Control stick rigging & elevator pushrods - (7 hours)       Category: Controls

Connected all elevator pushrods. Where the F-789 pushrod connects to the bellcrank just aft of the baggage bulkhead, it was next to impossible to get the required washers in there with the bellcrank installed, so I pulled the pivot bolt out, which allowed me to lift it up and get the lower pushrod attached correctly (the upper one was already attached) and then drop it back into position and reinstall the pivot bolt.

On the fwd end, I had partially installed the control stick assembly a long time ago. I had left the pilot stick out so it wouldn't be in the way, but after today, I wish I had put the whole thing in as a complete assembly. I finally got everything together but it would have been a lot easier if I had done it all on the bench.

I looked through the plans, the prints, and on VAF and never could find a spec for where the stick should be positioned when the elevators are in neutral. The only advice I found was to make sure it doesn't hit the panel when full fwd.

I tossed in a pillow and sat in the airplane to see what felt right, and set it where it seemed like it should be before sticking a bolt in the fwd end of the F-789.

Torqued all fasteners, including jamb nuts.

Started trimming the empennage fairing, and can confirm that he fit is likely going to be as bad as everyone says, but I didn't get any pictures of it today.

  Jan 04, 2021     Rudder pedal center brace - (1.5 hours)       Category: Controls

Match drilled the rudder center brace to the rudder torque tubes and the firewall angle. Also trimmed and added optional lightening holes per print, although I forgot to get a picture after that.

  Dec 28, 2020     Rudder pedal assy - (5 hours)       Category: Controls

This entry actually takes place over a few days. Due to the holidays, the family is home and I've just been ducking out to the shop for an hour here and there.

Fit the brake pedals to the rudder pedal assy, but elected to not drill the pedals to the master cylinders until I can sit in the airplane and play with the geometry to get the pedal angle in a comfortable position.

Drilled the blocks that the rudder cross bars nest into. These get match drilled to the skin stiffiner angles, so hole location needs to be somewhat precise. I made a jig for my drill press so that I could get them all as precise as possible. Drilled them to a #10 per print.

CAUTION- drilling these blocks to #10 makes sense because the holes in the plastic seem to shrink the second you take the drill out. But the holes you match drill in the skin stiffeners need to be drilled to a #12 or so for a AN3 bolt. If you drill them with a #10, they will be oversized.

I also had to trim about 1/16" off the end of one of the rudder cross bars. Only took a minute on the disc sander. There is a dimension called out on the print and a specific order these have to go in, i.e. one in front of the other. Because of the taper in the fuselage, they aren't the same length, and the print is very specific, not only about length, but about which end to trim if you need to shorten them. Also due to the fuselage taper, the holes that the bars ride in on the end blocks are at an angle, so they only fit one way as well. It would be super easy to both this when you're working in an upside down fuselage, so I took a long time with trial fits, measurements and lots of arrows marked in sharpie to make sure I had everything laid out properly.

I located the forward most position of the blocks. Per print, has the fwd edge of the block must be a minimum of 3" aft of the aft face of the firewall. That edge isn't parallel to the firewall, so if you mark your 3" on the skin stiffener, the top corner will actually be a little closer than that, so I measured back 3 1/8" and called it good. To adjust pedal position, the plans allow you to drill additional holes with a min spacing of 2 ED between holes so that you can position the assembly fore or aft.

I debated match drilling with everything in the fuselage with a 90* drill, but ultimately just unclecoed several pieces, took the stiffeners out of the plane and match drilled them on the bench with the blocks clamped to them.

The center support holes are on a different spacing, so theres the potential to run yourself into ED trouble if you don't lay out your hole spacing correctly. I spent several minutes trying to get fancy and calculate hole spacing that would allow me to pick up the same holes for multiple positions, but ultimately just did 3 sets of holes, moving the blocks 1" aft for each set, which hopefully will work out okay when in install and match drill the center support.

This will give me 3" of range for final pedal adjustment. I can't imagine I would need more than that.

  Dec 27, 2020     Brake pedals finished - (2 hours)       Category: Controls

The brake pedals come as thick blanks with the lightening holes already punched out. All the edges are really rough, and while I was able to finish teh outside edges on the #m wheel, teh lightening holes presented a problem. I did one by hand with some 120 grit sandpaper, but it took quite a while to get it looking decent, so I caved and made a quick trip to Ace for some small 120 grit sanding drums for my dremmel, which made short work of the rest of them. Finished with red scotch bright then countersunk and assembled per print.

I had originally planned to paint these with rustoleum hammered tool box paint, but it's been to cold to paint outside, and I have been putting off building a paint booth solution, so I ended up just polishing them with a 1" green scotch bright wheel on a dotco. Came out really pretty, and I might think about just clear coating these and leaving them this way. If not, I can always go the rustoleum route later.

  Nov 12, 2020     brake pedals - (4 hours)       Category: Controls

Fabricated parts as required and match drilled brake pedals. The ones on top of picture have been de-burred, the ones in vinyl still need some work I think I will paint these with Rustoleum Hammered toolbox paint. Depending on how they turn out, I may use it for some other stuff in the cockpit as well.

  Nov 12, 2020     removable copilot stick - (4 hours)       Category: Controls

The actual implementation of this only took about 15 minutes, but I researched it a ton.

Originally, the copilot stick just stuck in the socket with nothing holding it there. Supposedly, at some point, somebody pulled up instead of laterally and disconnected it while landing from the right side and bad things happened. Vans then issued a S.B. that calls for you to secure tis with an AN3 bolt oriented laterally (3:00-9:00) 1/2 inch below the edge of the socket.

This seems like overkill, especially since they originally had nothing at all holding it in there. Over the years, people have used all kinds of solutions ranging from fancy locking clevis pins to good old velcro.

A lot of guys have had success with the push button spring clips, but 90% of the ones you can find locally are 1/4" I decided if I was going to do this, I didn't want a hole any larger than the 3/16" that Vans calls out in the SB.

I kept looking until I found a vendor online that sold these with a 4.5 mm button diameter. I paid I think about $12 for the smallest pack I could get, which was a 50 pack, so I've got plenty of spares! 4.5 mm is obviously an odd size for anything I have going on but I went to the big bag 'o used drill bits and amazingly enough, found one that would work (#24 drill bit).

I also experimented with bending these into a couple of different shapes. In the 3rd picture below the bottom example is how they come and the top is the shape that works the best

  Sep 08, 2020     w-818 pushrods - (2 hours)       Category: Controls

Lot's of people report having trouble with these. The problem is that the threaded end is hollow, but takes two -12 rivets at 90* to each other to hold it on. The rivets are so long that they can bow in the middle in the hollow space + you're trying to set them in a round pipe, so all those things combine to make it pretty easy to get the tail clenched.

The ones I got with my used wings were dimensionally correct and structurally "okay" but the tails looked ...not great. So when I ordered the fuselage kit I had them throw in the stuff to make a new set, thinking that I'd have a go at making a set that were a little prettier than the ones I already have. My theory is that if I could keep the rivets from bowing in the middle, I would have an easier time of setting these with a hand squeezer and minimize the potential to clench the tails.

First order of business was to make all the pieces fit. The way these come, theres powder coat residue inside the pipe, plus according to my micrometer, the fittings are about .010 bigger than the ID of the pipe.

I cleaned out the pipe with a piece of sandpaper in a simple mandrel in a cordless drill, and took a few thousandths off the ends by chucking them up in my drill press and hitting them with sandpaper, followed up with a good polish with a scotchbrite pad.

Once I was confident that I could get everything together without resorting a hammer, I filled the cavity in the ends of the threaded fittings with 5 minute epoxy. I then premiered all the raw areas and assembled wet, then match drilled.

Van's calls out a -12 rivet here, but it's way to long. I think that they are hedging their bets against the rivets bending in the middle, but since I've filled up the hollow space with epoxy, that shouldn't be an issue, so I went with -11 rivets, and all but one of them turned out beautiful. On the one, the shop head is a little crooked, but not bad enough that I'm going to try to replace it.

Overall, I'm much happier with the result vs. what I inherited with the wings.

  Aug 19, 2020     Control sticks - (3 hours)       Category: Controls

Finished off and attached the control stick mounts yesterday. The plans imply that they're permanently mounted now so I went ahead and torqued them and applied torque putty, but I have a sneaking suspicion that they may need to come out again for one reason or another. Time will tell.

It also says that nows a good time to trim and rig the control stick assy, so I worked on that this morning. The control sticks ride in a brass bushing that slips into a clevis on each end of the cross tube. They come too long to fit into the clevis so you have to file them down to a slip fit. Same with the bushing.

The plans say both should be a slip fit, but Vans Airforce says the bushing should be a little longer so that in gets captured when you tighten a bolt through the whole thing. that way the stick weldment rotates on the bushing, rather than the bushing rotating on the bolt. I know if you take too much off, the sticks will end up having too much free play, so I was careful here.

Filed the stick weldments by hand a little at a time until there is about .010" gap in the weldment tube, and made the brass bushings a slip fit (.010" longer than the stick weldments) by chucking them up in my drill press and sanding the end down on some 100 grit sandpaper. Took a long time because I was going a little at a time and then checking, but the sticks should be buttery smooth. The print also says you should ream the bushings out to .25" One of them needed reaming, but the other one was already .25" without reaming, so I don't know what that's about.

Adjusted the sticks for parallel with the heim joints on the control column pushrod tube. Parallel turned out to be 18 1/2" inside to inside between the two sticks.

Everything in the stick assy is done, so I took it back apart, primed all the raw edges and put it on the shelf for now.

Had some extra time this afternoon, so I went ahead and countersunk the upper flanges for nutplates. I used oops rivets for these so I didn't have to take much off the flanges. Just did the countersinks by hand with a bit in my dogleg deburring tool. After countersinking, I primed the raw aluminum with some zinc phosphate primer on a q tip.

My std practice for installing a nut plate is to snug it down with a cut off screw and 1 cleco, so I can make sure there isn't enough slop in it to interfere with installing a screw later. This worked fine on the aft bulkhead flange, but for some reason the pre-drilled holes on the fwd one were undersized and a #8 screw wouldn't go through them. The print definitely shows them being the same as the aft one, but it seemed weird that they would be different, so I reached out to VAF to confirm that I wasn't missing anything.

Confirmed that they should indeed be #8 screws, so I reamed all the holes out with a #19 reamer, primed the hole bores and installed the nutplates in them per print.