Aeroworks QB 150cc YAK 55M

[Joe Hunt]

Okay, but here's what I speculate is the crux. And, if I'm right I'm kinda mad at myself because this is what worried me when I first went to glue in the hinges. I looked at the job, then looked at the instruction manual, then said to myself, "really?". I then called Rocco for, and I quote, "some criteria" haha, on how to put these things together for a perfect result. You know, what are the determining factors? Anyway, what I saw was the slots were cut out into balsa, and that balsa is a soft wood and these were big slots. In my mind, no way could I just push all the hinges down into that slotted cavity and have all the hinge pins line up. Sure if they jig drilled into a more solid surface I could do that with a precision result... but not a big slot into soft balsa. It was Friday night at 8pm and for some reason Rocco didn't answer the phone. haha So, I just decided to do it like the manual showed. "It'll be fine" I said. haha Well, imo, do not do it like the manual. First off, unless you're really good, fast, and organized, you will not have enough time to get all 12 of those hinges in. Second, I think I have a better way.

I already talked about gluing the hinges in the ailerons first, letting them setup, then gluing them into the wings. That is fast and easy. All good, except I still had binding past 30 degrees of travel. Why? Maybe partly due to the hinge pins not being in a line, but I speculate mostly because of the slots in that balsa that I was concerned about from the start. I had an idea. And, I think if I had another set of wings it would be even more obvious. But, I grabbed an elevator half. I put the hinges in, and just as I suspected all along, they do not finish in a line. You see I tried to use a straight edge to get the pins in a line on the first aileron hinge gluing I did. But, because of the pocket you can't do that. The pocket is in a U or V shape and doesn't allow you to see the side of the hinge pins to line them all up. But.... but.... if you don't do it the way it shows in the manual (of gluing it all together at once)... and you glue the aileron first... then you can use a straight edge to line up the ends of the hinges. That will line up the hinge pins!! If you hinge per the manual your hinge pins will not be lined up. Again, that was my initial fear and I'm mad at myself for not working it out before I started gluing. I never used to look at manuals, I'm getting old. haha

Here is a picture of the hinges pushed into the elevator... when the straight edge hits two of the hinges the others are all short of hitting the straight edge. Meaning the hinge pins do not line up. You know that ain't good!

[Joe Hunt]

I'm going to try my theory out on the elevators (that even with the hinges installed dry still had binding, which would make sense if the pins are not lined up, we need to line them up I think), and report back. I speculate that the following method will be good for getting a decent result with these hinges.

Glue the control surfaces first and let them setup before installing them in the plane
1) Lube the hinge with a thick coating of lube
2) Glue the hinge in to the control surface
3) Twist the hinges to align them until they move freely full travel in the slots
4) Use a straight edge to line up all the ends of the hinges (if you shaped some upholstery foam to keep the hinges all straight out, but on plane with each other, while doing this... all the better)
4a) Square up all the hinges to the leading edge of the control surface
5) Let that setup
5a) After the glue has setup on the elevators, clip an 1/8" off the end of the two inboard hinges (I dry fitted fine here, but after I aligned the hinges with the straight edge I was not fine, had to make a quick cut during gluing)
6) Put glue in the wing (or stabilizer) holes
7) Take a paper towel and denatured alcohol and wipe off any glue around the holes
8) Put glue on the hinges and push the hinges into the wing
9) Put in the card stock shown in the manual, and even then have the card stock in there pretty loose

That might be about as good as can be done with these. I'll try it on the elevators and report back. It's more critical on the wings, though, as there are 12 hinges across a long aileron. Plenty of opportunity for hinge pins that don't line up. But, I think this method will provide a decent result.

[Naughty Monkey]

So the hinge line of the aileron is not parallel to the trailing edge of the wing? Thought i was done trying to figure out geometry.

[Joe Hunt]

[Joe Hunt]

Okay, 100% success with the elevators with this method (slot end to slot end with no binding, over 60 degrees of travel):

Glue the control surfaces first and let them setup before installing them in the plane
1) Lube the hinge with a thick coating of lube
2) Glue the hinge in to the control surface
3) Twist the hinges to align them until they move freely full travel in the slots
4) Use a straight edge to line up all the ends of the hinges (if you shaped some upholstery foam to keep the hinges all straight out, but on plane with each other, while doing this... all the better)
5) Square up all the hinges to the leading edge of the control surface
6) Let that setup
7) After the glue has setup on the elevators, clip an 1/8" off the end of the three inboard hinges
8) Make sure hinges go stop to stop without any binding. Clean out glue and/or wood until there is no binding.
9) Put glue in the wing (or stabilizer) holes
10) Take a paper towel and denatured alcohol and wipe off any glue around the holes
11) Put glue on the hinges and push the hinges into the wing
12) Put the card stock in loosely or use two pieces of card stock

STEP 4

STEP 5

[Naughty Monkey]

Other than being scale, which does look cool, I don't see the advantage to doing it that way. Looks like it is just asking for trouble with improper installation. Also curious to see how the performance is. I have heard that pocket hinges don't perform as well.

[Terryscustom]

[Joe Hunt]

[Joe Hunt]

[Joe Hunt]

Hey Naughty Monkey! What are you flying these days? And, what are you thinking about to put together next? We're always thinking about the next one! haha