Ch 19 Wings, Alierons

Aileron Refitting

Date:  11-01-2021
Number of Hours:  10
Manual Reference:  

The ailerons are back in the wings. Maybe for the last time.

Some time ago I prepped the long pushrods with primer and topcoat. Not my best painting but I have protected the aluminium and those rods are not on show. I do like to do my best when I can noting…

Voltaire said, “The best is the enemy of the good.” Confucius said, “Better a diamond with a flaw than a pebble without.” And, of course, there’s Shakespeare: “Striving to better, oft we mar what’s well.”

Did I mention the over two month wait for special liner for the hinges after I ran out? Then many hours putting them in. Please pretend you can see them.

While the ailerons had been on pre paint, after paint it was a problem. I had to sand carefully for some hours to get it all to fit again.

The specs are 2.1″ +-.3″ I think. Deflection in both directions inboard end. Up is easy.

Hard to see here but I made 2.2″ down on both sides. From here its just stick and pushrod adjustments to make it all correct. I needed to ensure I had the possibility of the 2.1″ all over.  All is good. Roll rate for a swept wing is slow anyway and I’ve never run out of aileron on my flying LE with the 2.1″ deflection.

I’ve used these small metal locknuts and a thin washer and have thread showing in spec everywhere. As is my practice, once tightened for the final time I add a little blue torque seal to remind me no need to re tighten here. I just wish the seal came in a better tube, its a mess.

Aileron Final Balance and Weights

Date:  09-10-2021
Number of Hours:  11
Manual Reference:  19-9

Balancing the Ailerons (and elevators) is one of the critical things to ensure the greatest possible air speed (TAS) before I encounter flutter. It is one of the factors that will determine my VNE.

Here’s what the plans say in Chapter 19. Riding on the wisdom of others instead of a solid steel rod. I opted for a hollow steel tube.

This steel tube you can see in my first weigh above is not yet filled with anything. Naturally we have the aileron hanging trailing edge low.

Yes thats lead of the exact diameter to stick into the tube. Instead of a hit a miss method I can control exactly the balance I want.

I left it a little long so I could get the insert in and out as needed. In the end I filled the whole tube with lead.

You can see that I’m pretty much in tolerance here.

I’ve just used some thin aviation lock wire and an overhead shelf which worked a treat to hang the aileron.

Its a bit hard to photograph, I added a bit of string to help. On the job a small steel ruler can be held up instead.

The idea is that the top of the spirit level is parallel to the bit of string. I have it almost perfectly balanced for both ailerons. The plans give a bit of a margin and I think thats because if you just glass in a weight per plans its a bit hit and miss. If you miss by too much you get to scrap the aileron and try again. With this tube method I really can go for accuracy.

Once I was happy with the weights I needed to secure the rods in the tube. I just pulled out an end several inches and used epoxy. While it was still wet I pulled the other end out and did the same. I little back and forth to get the glue in and that was it.  The lead is so soft I could cut the ends off with a steel backed razor blade to tidy up.

For those who care, here are my final weights. I think I built these as light as was reasonably possible and I’m happy with the results.
After all, no one builds as light as Mike Melvill!

Aileron Weights
As reference Mike Melvill’s aileron weight before paint was 5lbs 2oz
Mike’s plane was one of the fastest constructed and lightest ever built.

Right        3lbs 12oz (1.685kg)  Painted 3lbs 15ozs (1.757kg) 2.5oz of paint
Final Weight after adding lead to the trailing edge tube  5lbs 13oz (2.625kg)

Left          3lbs 13.5ozs (1.745kg)  Painted 4lbs 4oz (1.83kg) 2.9oz of paint
Final Weight after adding lead to the trailing edge tube  5lbs 11ozs (2.574kg)

 

 

Wing Root Heat Shields

Date:  07-29-2021
Number of Hours:  18
Manual Reference:  19

Both the spar and the wing root area needs heat protection. Just engine heat and of course protection to give a few more seconds in the case of an engine fire emergency.

I’ve gone with a new technology ceramic heat shield, Zircoflex II. I had very good support from the Australian Distributor. The product comes with a quality 3M adhesive backing and just needed cutting with scissors to fit.

Cutting to fit meant I needed a set of templates to maximise  the material with a minimum of waste,

It took quite a long time to generate an exact set of thin cardboard that fitted my rather odd shapes.

Once I had the sets cut out it was easy to use the Zircoflex sheets with a minimum of waste.

Fitting was just removing the backing paper to reveal a very sticky rear end.

I spent quite a while with a wooden roller and then a wooden ice cream stick. This works a treat for getting the foil to really sit down in the corners and on the flats and intersections.

Its a good clean result.

 

 

Refit Ailerons and Clearances

Date:  03-24-2019
Number of Hours:  6
Manual Reference:  25-6

Having filled and fared the ailerons I again refitted them to the wings.

With the ailerons back on I was confident to run a sanding straight edge down the trailing edge.

There is a crispness to the fit of the edges which is quite satisfying. I will balance them AFTER painting where I have the capacity to add lead as required given I used hollow counter weights.

A slightly less pleasurable fit was noticing that the bell-cranks were just far too close to the bottom of the wing.

It was the same on both sides. After a very careful ‘sand’, this glass to glass area became acceptable. I was super careful when I did this part of the build some years ago but here we are. Now is the time I begin to fix whatever is not quite right as the finishing line is in sight and nothing can be put off for later. Later is in fact, NOW.

 

Right Aileron Trough layup 1

Date:  12-02-2015
Number of Hours:  5
Manual Reference:  19-8

I did quite a bit more prep and the layup in one day but I’ve spread it over two entries so there are a few more pics for you… whoever you are :). I’d also hot glued aluminium angle to the outsides and prepared sticks and things for the inside clamping, cut out all the glass and foil pieces and written up schedules for the layups as usual.

I made a really long board for the main 3 ply foil layup. I’ve gone for an exact length and then I’m adding a small three ply piece to the outboard part of the rib as a separate overlapping piece. This way my main piece doesn’t have to have that extra width all the way to the end. The inboard section will be done at another time.

I spent some time with micro on the blue foam as you see in pic 2. Once that was done I mixed a really stiff batch and did the corners and a few divets. BID rarely goes down without a few tiny voids but I do want to minimise them and have no bubbles of course. I use my fingers a lot to get things sitting down and allowed a bit of time for the epoxy to start stiffening up a touch.

Pic 3 shows the foil in place and partly smoothed out. This is a great method. The plies are nicely wetted out and the foil allows a lot of time for getting the BID sitting well in the corners and flat on the sides.

Long 3 ply BID

 

Microed trough

Foil going down

Wings Stowed, Fuselage Floored

Date:  03-02-2016
Number of Hours:  0
Manual Reference:  19-9

Darren was invaluable in getting these wings up on the shelf. There really isn’t enough room and its a challenge not to scrape the ceiling. Next time three people. Yes they weight 63lbs of the most awkward strangely balanced shape you are ever likely to handle above your head. You have been warned. Thanks again to Darren.

I draped some black plastic for UV protection. I don’t know if its necessary. It wasn’t that hard to be careful. It will be a little while before they come down again for fitting the strakes.

Time to work on the controls and side arm rests and a few other things. After a bit of a think I pulled off the gear and retracted the front wheel. Then bought some nice new foam mats and enjoyed all the extra space. NICE!

Wings shelved

UV protection

Fuselage minus gear

Bare Wings Done

Date:  02-18-2016
Number of Hours:  1
Manual Reference:  19-9

Just for the record I’m using FK male Rod Ends, JMX4. HEIM are specified in the plans and cost between $150 and $200 each. Max Static load is 1,550lbs. The JMX4 load number is 5,262lbs and the weight is less and they have strong teflon liners (no oiling) …oh and they cost about $36 each. I used a #3 ball tightness. Yes you can specify. #1 is super stiff. CGB precision bearings was the place if you are in Australia.

These pics show the aileron hardware in place. Everything is free and clear and working. Pic 3 has the work area which will change as soon as I can get some help lifting the wings onto a big shelf.

Any takers?

……. I think the wings might be finally done for now. Yipppeeee

Igus bearing

Wing bellcrank

Work area full

Aileron Hardware 2

Date:  02-17-2016
Number of Hours:  10
Manual Reference:  19-9

I found that the upper rod end was touching the wing root edges and you can see in pic 1 I have hacked it away (carefully of course). I also spent a while getting the bellcrank to sit where it should before drilling out the taper pin as you see in pic 1.

Pic 2 shows I’ve done a big clean up and added three plies of BID. I’m not sure why the plane is giving me the blue finger? Anyway all fixed over a couple of days and pic 3 shows again re checking that all is well.

Side clearance

The finger

Free and clear movement

Aileron Hardware 1

Date:  02-16-2016
Number of Hours:  5
Manual Reference:  19-9

Lots of time doing little jobs here. After a lot of fiddling and checking I mounted the CS127 plates and tried a few sizes around until I had the right bolts. Not quite what the plans say.

I played around for a while with hole practice and found that my simple drilling jig, four clamps and a cordless drill worked well. as shown in pic 2.

The CS129 tube needed rivets and I couldn’t get the right size. I ended up with longer ones and ground them to the 11/2 times diameter proud of the hole as they should be. A bit of practice and OK rivets were produced.

Drilling in tight corners

Straight holes

Riveting

 

Aileron End Cove

Date:  02-15-2016
Number of Hours:  5
Manual Reference:  19-9

This was over a couple of days… or rather very late last night and today after much sanding during the afternoon. The job was the inboard aileron coves on each wing which I had left out until now. I didn’t know what the final shape needed to be until the aileron tube was installed so I just left this out initially.

Pic 1 shows a pretty strange shape for the layup. I just tried a few bits of plastic in the hole and this seemed to be what would work out. Its three ply of BID and all done as you see in pic 2. The usual pure epoxy on the glass to glass areas, slurry on the foam.

Pic 3 its all cleaned up, nice and smooth the nothing binds on the sides which had been a major consideration at every slow step of this part of the build.

3 ply on plastic

Cove layup

Trimmed and smooth

Aileron Taper Pins

Date:  02-14-2016
Number of Hours:  5
Manual Reference:  19-9

These jobs were over a few days. Pretty much ensuring my tubes were the right length and putting the ailerons in and out with the wing pivots held in place. Just lots of measure 10 times drill once stuff.

Pic one shows me reaming for a taper pin. Love these things… no slop. Pic two shows the source of my universal joint shims which I cut out and glued in place. I just don’t understand why these parts are undersized. Maybe someone will write me and I shall be re educated. Meanwhile I don’t like very loose fits in my parts… aluminium can seems just the right thickness.

Pic three shows the aileron with its pushrod. The end comes off then the rod is threaded through the wing and the aileron seated in its hinges. I’m getting pretty good at doing this. Its all about practice.

Taper pin install

Shims

Aileron push rod

Aileron Controls Trial Fitting

Date:  02-12-2016
Number of Hours:  10
Manual Reference:  19-9

Quite a bit of time fiddling around doing trial fittings. The CS150 bearing is in place and as you can see held in with two AN bolts into the nutplates. I did add 2 pliess of BID over the top of the metal locator first, let it cure and then cut the hole for the plastic bearing and opened up the bolt holes too.

Next up was a bit of trial fitting that I’m still doing. I have made up the CS129 tube with inserts for the rod ends. For now I’m using some plastic ones while waiting for the metal rod ends to arrive. I’ll give specs on those later.

I wanted to see how the metal parts were going to move around as you can see in pic 2 I have to revise the clearances at the top and I’ve cut the aileron to wing root tube as well, CS151. Just working to pin on the universal join with taper pins.

Yes the taper pins are AN386-1-7 and I’ve sourced some washers, AN975-3 which you can see in pic 3. I have the #1 taped reamer for this and have practiced getting a few holes before the real thing.

CS150 bearing

Trial fitting

Taper pins