Hi Dart,

I've been following your build for a long time. Glad to see she nearly airworthy again.

BTW I went to your new website and I'd like to point out a wee problem with it. If you click on any of the working links and then click on the Home link it puts a whole new menu/windows in to the display area (easier seen that explained). I think all that is wrong is the Home link is "http://www.darts-page.com/index.htm" and it should only be "index.htm".

Not a criticism, only trying to help.

Anyway, keep up the excellent work.

Cheers,

Andy

That's a long way to go, but cool to be invited.

Regards rigging, is there any special trick to it? How do you know you got the tension right in every wire?

When everything is tight-ish and the upper wings are leveled to the fuselage.

I'd like to say there's some sort of high science involved including wire tension gauges and stuff, but on these kites there's a bit more art involved.

Basically, one levels the aircraft as if in flight, both along the fuselage and across the front.

All the turnbuckles get tightened to about two threads showing.

Starting from the landing wires, which hold the lower wings up, one tightens them until the upper wing is level across the bottom (there is almost no airfoil there, as the ribs are basically flat, and it sets the right angle of attack for level flight). Once that's done, tighten the uppers to not show threads.

Double check. If it's now screwy, adjust as needed.

The wires should be close to the same in tension, but it's not rocket science. It's hard to explain how tight - I just strummed the wings of a bunch of flying types of this aircraft and it's sort of a low G string sound - enough to where it's not trying to pull the airplane into a ball but tight enough to keep everything solid.

Only the upper wing is measured for level, as the lower wings are at a dihedral and will follow the upper wings. I've long suspected they're mostly there for structural stability, working as a lifting surface as well.

I encountered a problem requiring some minor surgery during rigging. The left front inter-plane strut was slightly damaged, dimpling where the final front drag wires went through it, and cut a bit short during the build process, so I'm going to replace it. It should be here by the end of the week. So I'll have to remove it, measure to fit the new one, cut, cope, and replace. Thirty minute job once the tube comes in.

Dart,
You have just described how to relace and true a spoked rim. When it comes to spokes, they now have a special torque wrench to take the art out of the process. I still prefer the old school. (shock).

Sorry you bent the old girl, but I for one, have enjoyed the drama of your journey.

Thanks for the explanation. Seem to remember that in WW1 the rigging kind of could give different characteristics to the same aircraft.

Aldo said it well with his last sentence.

Aldo, this is much easier. I gave truing a wheel using the little wrench a spin (!) and figured out it was worth the ten bucks in my time to have a bike shop do it. I was chasing my tail with so many spokes. This happens in a lesser degree with airplane rigging - sometimes one has to just loosen all the wires and start over.

Colonel, rigging very much can change flight characteristics.

If the top wing isn't level all the way across, it will induce a roll, as the airfoils won't be the same. Or it may break to one side instead of another or straight ahead. Or have one aileron more responsive than another.

Of all the things I worked on in building the plane, rigging the wires took the most time for any single task, including rebuilding the engine. The better the rigging, the better she'll fly, so I went through a lot of wire and nicopress fittings figuring out how all the wires interact.

Since she's ground trimmed, this also means adjusting the angle of incidence on the horizontal stab in the back. Right now it's set to where I'm a touch nose down at cruise, giving me a nice hands-free straight and level flight. It also means that on take off the stick is slightly to the rear, ensuring the tail doesn't come up until the rudder has enough bite of air to keep me from departing the runway. She takes off from a near three point attitude, which is actually pretty common for this type of aircraft, as in reality she's just a fat ultralight with tons of power for her weight and thick airfoil.

Wonderful stuff Dart. Your description of leveling the wings and induced roll makes me think of the early wing-warping control method.

It is exactly that.

Sadly, the new tube hasn't arrived....I guess USPS is running a bit slow.

I went out to the airport with a long bit of wood measure out the new strut, as it's a lot easier and cheaper to cut down and whittle a bit of lumber than a flattened tube.

I also had a bit of a flashback. I pulled out the plans to see what the length there called for and laughed. "As Required," is the dimension listed.

So using the other one as a starting point, I matched it and fussed a little to get the measurements just right:



It's just held in with clamps, but the wing is level with a little tension.

Speaking of which, with the strut longer than the one I had originally installed, my wires are too short. At least too short to tighten without leaving threads exposed. So I get to cut and swag new cables. Hurray!

I guess my deep desire to drive my swagging tool (unaffectionately known as the M'Fer to me) to the Tennessee River and throwing it as far in as I could was a good thing to have repressed.

She may be a pain, but she sure is purdy.

Like a lot of slightly worn French girls, though, she gets a little less attractive the closer one gets.

I've decided that she's probably from Alsace, as I tend to talk to her in a bit of German from time to time and she doesn't seem to mind.

You got the patience of a Saint.

No, just an almost inexhaustible well of profanity from which I draw on.

Tube came in Thursday, so Friday I went out, measured, cut, and painted it.

Today I went out and mounted it and cut new wires. She rigged true!



So safety wire, patch the access holes I had to cut into the wings, connect the aileron control rods, and re-time the engine.

Well, I'm calling her flight worthy, though there are a few things left.



I did a bunch of taxi tests with the brakes, using actual testing methodology:

I took temp readings of the brake drums using an IR thermometer from cold (okay, that's relative, in the hanger, in shade, they were 88 degrees).

To see if there was drag on them (the wheels spin freely when lifted from the ground, but there's some flexing of the wheels with the weight of the plane on them moving over ground), I taxied about 500 yards at a normal taxi speed and let her roll to a stop after killing the engine. Twenty degree increase on the left drum, ten on the right. Slight squeak at the end of the roll.

Stopping required no adjustment of the tailwheel to stay straight.

500 feet taxi at normal speed, hard braking at the end, bringing me to the halt with the engine off in about 20 feet. Thirty degree increase on the left, twenty five on the right.

Braking required no adjustment of the tailwheel to stay straight.

1,000 feet faster taxi, brakes used once to slow, full brakes at the end with the engine at idle. She managed to stop in about fifty feet ( ), with some noise. Oddly enough, thirty-five degrees temp increase on left drum, thirty on the right. I'd of thought it would be higher.

Last test, after the drums cooled a bit, was holding from the start. She'll hold firm from idle to about an eighth of increase. After that, she'll roll - but not real well, and it's a gradual grabbing and not locking up though all the throttle I was willing to give her (about half). As expected, she did want to go left, but only a little.

One of the guys watching all this foolery brought up a good point after I got done: the drum is on the outside of the pads. As they heat up they expand away from the pads. In the band brakes, it was the other way - as the drum heated and expanded, it was into the band, actually increasing brake efficiency.

Small repairs to the gun - "heat shroud" replaced with a new bit of PVC pipe, new barrel to extend from it fabricated from a bit of spare tubing, crack in magazine glued and re-painted (it's not invisible). Everything re-painted, in fact, and I set it up to dry before I it gets put back together.

I have a small amount of oil leaking from around where the prop hub goes into the engine. This is really weird, as the spinner cup and the seal in front of it should make this pretty much a spot for casual oil. Then again, this is the first time I've really cranked up the RPM's since rebuilding her, and I need to check oil levels. I may have a bit too much in, as I had to add to account for the huge oil cooler.

In the VW, to really check the oil level one has to lift the tail to get the oil pan level.

Oh, and the airspeed indicator. Someone on the EAA forums mentioned that they had the same problem as I do - reading 10 MPH too fast - and fixed it by moving the static port to the rear of the fuselage. Or I could pull out the pitot tube/static probe combo thingie and mount that...but I'm kind of enamored with the idea of the mechanical paddle-on-music-wire ASI that Rick Bennett came up with and will dink with that.

So it's now down to waiting for weather, a nice calm morning and a ground crew to start all over back at Flight Number One. My plan is the same as it was back then - go up, fly a close pattern, land.

But I got to say I got a huge thrill pushing the throttle forward and feeling the aircraft around me. If the winds hadn't been pushing, I'd of gone up yesterday.

Congrats on getting her back airworthy, Dart!

Congratulations!

good work there Dart and a great read

Congrats Dart!

Stay safe!!!

Even though the picture is a bit small that smile of yours could have been seen for miles. Glad to read that your bebe is in working order once again.


Wheels

Strong werk. Glad to see you smiling in front of your beautiful labor of love.
Looking forward to your next hop.