Rudder Pedals

I did some work on the rudder pedals. I did a test wrap of the 1" wide cloth a while back with quite unsatisfactory results. After cutting all the wrap off and sanding things flush again, I decided to go with some 6oz S-glass I had laying around. I put a similarly sized piece to seal the top and bottom of the pedals and then did a bias cut wrap around the pedal in one piece, using 3M Super 77 to make it all awesome. This is tremendously nicer than doing it with strips and the 3M really helped too. I show here one pedal wrapped except for the little exposed piece at the bottom and the other pedal with just the top end seal done. The other ends of the tube were sealed out with a hunk of foam wedged in the end of the tube. The bottoms will just stay open.

I actually epoxied them tonight too. I used an acid brush to push the epoxy down through the layer(s) of glass. It's not the most structural way to do it, but this is just a rudder pedal, so I have no doubt even this method is overkill. I wrapped the pedals in peel-ply to make a prettier finish and stuck them in a trash bag and used my vacuum to give a few inches of vacuum. It actually pulls down pretty well and I'm sure is more pressure than my tool chest's weight over the area of the pedals stacked on top of each other. This'll keep 'em flat though. Tomorrow I open my Christmas present and see how I did this go around.

I also put in two more sleeves into the cabanes that I missed the first time around. Now I simply have to replace the upper aft triangle tube that was a little short and the cabanes will be happy.

Progress is fun. It'll be nice to work through getting the tail group completely installed and take this puppy outside for a real assembly! (without the wings yet of course)

By the way, to the gifter of the drill, it works quite well, thank you :-)

Short update

I have a few pictures for this update. I am sort of in detail-mode right now. I'm out of all the big tube material from last order, so it's time to start tweaking those little details that I glossed over to make forward progress. For instance, I used my West Marine quick-link and some sampled (free!) Alliance Plastics plugs on the nose area to make the tow release. The end caps sure clean up the look of the nose too. I sampled some more end caps hopefully to close out all the 1" tubing in the seat area and give that some more professionalism.

I worked on the aileron linkage underneath the seat too. I added the torque tube doubler (missed that before), so I feel much better about man-handling the controls (though as I understand it, the control forces are actually fairly light). I also split the PVC pipe and filed away material to make a "C" shaped until it fit with just about 1/16" of gap when the C was closed up to a circle. When I glue the bushing into the frame, the epoxy will help keep this gap from opening. Additionally, I added the 1/4" retainer piece to assist holding that bushing in place. I thought about leaving this with cleacos, but they interfere with the aileron crank, so I went ahead and riveted the support piece in.

As you might tell from the photo, I'm also concentrating on replacing any short bolts with ones that clearly use the shank as the load bearing intersection, instead of the threads. This also means I have at least 1.5 threads showing outside the locknut. I think this is proper use of these bolts, but I'll still have an A&P look over the structure before I do any covering. No sense in pushing when I have wiser folks around to critique.

Last, I added a couple of the line guides for the elevator control system. They are made from 1/4" x 0.035" tube ovalized to 3/16". The tiny supports are cut from the same ovalized stock and I used a Dremel sanding drum to put a curved surface on the ends of the support. This lets the supports have better surface contact and really takes no extra time.

I shall head off comments about the test control line saying it's some parachute cord that I had laying around and is just for mockup purposes. I'll get real spectra/dyneema when the time comes for rigging the lines.

Question: Do the ailerons need some stop-blocks somewhere? My aileron crank touches the wheel at full stick deflection and makes the wheel harder to roll. Maybe Sandlin used a rounder wheel?

We have a tail!

I made a bending jig from a few spare drill bits and a bench vice. This kept from marring the surface of the soft aluminum parts. It took a few tries bending to get the right angle. I bent the pair at the same time so they have the same angle. Eventually I cut the two parts free, cleaned everything up, then started tweaking them individually... I really should mount my vice to the bench.
After a while, I mounted them to my jig and got things moving. Spaced properly and with a perfectly fitting bolt between the two tabs, I was able to match drill each of the connecting holes one at a time to have a perfect joint. Yay, one more hard step to go!




Then I finally actually mounted the tailbooms! The lower one was considerably easier with the nice alignment from the jig and all the close-up attention. The top one wasn't quite as easy. But it's done, so that's that. I used a 3/16" bolt so I can enlarge to 1/4" like I'm supposed to and take care of any misalignment.

I'm happy to sit in the seat with the tail sticking out behind me, self-supported. I just have to be careful not to lean it over and twist the two joints all to pieces.

The tail is almost on

I'm making great strides on the vertical tail, almost to the point of getting it put on the fuselage! To start, this is where I am with the vertical tail. I'm out of 1/4" tubing for the truss structure, but what I have done gives me a good idea that adding the other trusses will be pretty trivial. I did 3M the glass tape on the two rudder ribs that had not been finished. I will indeed be taking out that one finished rib and redoing it.

Here is a closeup on the lower rudder connection area. You can see the vertical tail ribs made of 1/4" tubing and the different composite rib on the rudder. The lower rudder hinge area is that crazy bolt area in the middle of the photo. I put the rudder stop blocks in yesterday too, though one is a touch longer than the other. I think I'm shooting for about 20-30deg of rudder deflection until I can find the recommended throws. I also pinched the tail skid with the intention of rounding it off somehow later.

I also have the top rudder connection pretty well completed. The hinge was a piece of cake part with a slight bend in it and the tapered rib on the vertical tail is the same as on the lower side. You can also see the horizontal tail connection part, yet to have a modification to further thread the bolt for a captured part. The rudder rib in the lower left hand of the photo is the one I'll remove and redo. It might look decent from this zoom level, but I'm just not happy with it in person. In other news, I have not put the elevator control rigging slot in the upper boom yet (that would be between the rudder post and the h-stab mount). I'll probably wait that one out until I start all the rigging.

To mount the vertical stabilizer to the fuselage, I made a little tooling jig to hold the mounting flanges the proper 1.75" distance apart. This way, I would be assured that the tail boom would fit perfectly and the fuselage holes would be match drilled to suit. Unfortunately, where I put the bend in the mounting parts meant the bolts would physically conflict with other bolts in the area, so I have to redo those parts. This next time, I'm going to leave the fuselage end undrilled until I can hold them both up to the fuselage and ensure proper clearance. I am pretty happy with the jig though! It looks ungainly, but it worked great for the test fitting.

Finally, I leave you with a shot showing the temporarily clamped beast all put together. I don't have a wonderful place to take photos, so it's a busy background, but I think the idea still gets across .... the tail is almost on! It's remarkable to put it all together like this and realize this is actually going to be an airplane :-) I'm excited to finish off the little material I have remaining and do some cleanup on the tail section. I think within the week I should be able to get the v-tail actually mounted to the fuselage and start mounting the horizontal stab too. Perhaps I'll work on the tail ribs some more as well and feel like I'm actually finishing something off. Right now I sort of feel like I've started all the major sections (less wings of course) and completely finished none of them. Perhaps the rudder should be first to finish. Who cares though, I'm having fun :-)

"Storm of the Century" aftermath

I wasn't kidding about the snow ... I took this picture just before dusk and the snow was still coming down at +1" per hour! It just quit (9pm) after starting up last night just after 9pm. 24 hours and roughly knee-height snow and definitely over my knee in drifts. I won't be going anywhere anytime soon...

I should have ordered another 8' section of 1/4" x .035" while I was already paying for shipping last order. I have a few of vertical tail ribs to go, but the aft four are all done (pictures tomorrow). It's nice to start cleaning up and seeing the vertical tail start to really stiffen up.

"Storm of the Century"

Why is it that snow inspires me to work on Goat? DC is in for "a historic snowfall" tonight according to the meteorologists on the news. I took the quiet day to work on the tail section now that I'm back with all my parts and tools!

First, I sampled a rubber/plastic handle for the control stick. It isn't much, but it's very pretty looking. I think it is a little detail that adds a personal touch to the otherwise very metallic and impersonal beast. I haven't glued it on, so I can twist it around and somehow slide it off now, but I've heard of some tricks with hairspray for bicycle handles that might work. If nothing else, I have some 3M Super 77 that will make the two parts neigh impossible to separate...

I also installed the 1/8" quick link from West Marine in the upper elevator arm (hard to see). I have the pulleys too, but figure I'll hold those off for a day when I only have enough stamina for a 10 minute job (or when I decide to get the 40 some odd quick links).

Then, for whatever reason the mood struck me and I made channels in the horizontal stab ribs for the carbon caps. They're not glued in yet, but I'm about ready to do it (and probably will tomorrow night). I realized I forgot my magic trick for the fiberglass wrap on the rudder ribs: 3M Super 77 to make putting down the cloth a breeze. The rudder ribs were torture trying to hold the glass in place while squishing it with a peel-ply wrapped layer being pulled taut. Now I just can pre-bond in the carbon spar then gracefully wrap the 3M'd glass around before saturating it with epoxy. Duh to me, that'll work super well.

Now I started on the fun stuff, making the vertical tail. I quickly made two gusset parts and bolted them carefully to the upper tube and allowing to align the middle tube with the proper twist. The middle tube with all the rivets in it was already done from my last post.














Then I made slowly the four sheet parts to attach the rudder post to the upper and middle vertical tail tubes. Making the rudder post assembly let me match drill the upper and middle tube holes perfectly. A little while later I made and attached the upper rudder hinge.

The lower rudder hinge is a simple trio of AN42b eye bolts. I'm not really sure why Sandlin used the eye bolt pair and axle concept here and not elsewhere, but I like how friction free it is compared to the elevator. I'm going to debate for a while if I should do the same on the elevator. It's the idea of adding another pair of holes so close and in a critical part, we'll see...





And then to cap off the day's work, I made the horizontal stab bracket to mount on the vertical stab. I did the front one too, but put a circular hole in it and forgot it was an eyebolt that needed to go into a slot ... so I'll remake that part later sometime. I have not yet modified the AN3-30 bolt with more threads and no head to match Sandlin's drawings. I need to borrow/buy a die set to make that one happen.



This is a bad picture, but I really wanted to get the point across that this plane is really coming together! Sure there is a long way to go, but it's fun to start making an assembly :-)

A trip to West Marine

I decided to go get some more parts for Goat. Unfortunately, West Marine didn't have any more quick links than just this one, nor did they have the Ronstan shackle RF1853. Bummer. That's okay I suppose though. I'll try again later at another store...

I also need a cheaper source for 1/8" steel quick-links than West Marine. I counted over 20 at first glance at the plans and at $7 apiece, this begins to hurt a little. Surely there is another source without as much markup.

The pulleys are super sweet though!