Ok, got a little more done:

The retract holes were marked and the wheel wells were cut. Note how the foam holds the sheeting firmly in place

Then the slots were cut for the wing joiner.

The wing is now joined, but I'm having difficulty with my camera cord, so I can't download the pictures. I have another cord at work, so I'll post that pic on Monday.

BTW, here's a little building tip for you new kit builders...

Sometimes you need to shave sheeting with a razor blade or Hobby Knife. Often, the line you are trimming to is not exactly parrallel with the wood grain.

A razor blade will follow woodgrain. So always cut in the direction where the grain will force the blade AWAY form your line, not toward the line.

In the pics below you can see the grain (Blue Lines) and the angle I need to shave down to (Red Line)

If I shave from Left to right, the grain will try to push my blade away from the trailing edge (Which is what I am trimming the sheeting down to)

If I go from right to left, the grain will try to pull my blade INTO the trailing edge - which could possibly cause me to cut too deep and gouge the TE.

Well, I got lucky today and came up with a US-60 kit, I won't have to wait until April. I'll order up another .75-AX and get building. I've been going nuts here during the evenings without a plane on the bench.

I'm sure the answer to this is somewhere online but is everyone using 90 degree retracts or will something like 85 degree be better? I know the bottom of the wing has some dihedral angle but I wasn't sure how much.

Hi MinnFlyer,
Looking good. Are those Robart struts? If so, which model number? I may have to try some, they would probably help smooth out my ham fisted landings a bit!!

Thanks,
Oly

Chuck, 85 might make the LG go straight down, but then again, they might make the LG point in a little (If the dihedral is less than 10 degrees)

I don't know what the exact angle of dihedral is in the US, but it looks like less that a total of 10 to me. And the gear would look more normal to the human eye if they were out slightly rather than in.

Oly, Yes, those are RoboStruts. I used them on a few review planes and really like them. They're a bit pricy, but I splurged on this one.

Here's a link:

http://www3.towerhobbies.com/cgi-bin...&I=LXES65&P=ML

Thanks for the link, MinnFlyer. I'll check the RoboStruts out. I glued the basic fuselage frame together this morning on my US 60. It's starting to look like an airplane!

Oly

I flew mine for the first time today and it went off with out a hitch! Good luck to all the folks building an Ultra Sport.

Doncha just love that?

Congrats GR!

Ok, the latest pics:

I got the two wing halves epoxied together, added the trailing edge pieces with the torque rods (For Flaps), sanded the flat on the LE and TE, and (Back in the dirty workshop where I have good ventilation) I epoxied the fiberglass to the center section.

Nice wings. So I am at the point where I am fabricating the cowl - fiberglas is bad from what I hear ;-) - but I want to use a tower 75 for my engine. Trouble is they are back ordered until late Feb. I have an OS 90 in the box and I was wondering if I can use that for spacing purposes? Are they the same size or is the Tower 75 smaller? I want to get everything set but I think since this is fabricated to the engine it is an essentila thing. I don't think I need to go with the OS 75 for this and for $100 difference I think I can wait.

I'm really not sure on the sizes of those.

I'm going to be in the same boat pretty soon, I loaned my OS 75 to my brother in Florida. I don't know if I should ask him to ship it back to me, or if I should just wait till I visit him the first week in March.

Very nice looking work, MinnFlyer.

Question: Did you join the wings by simply following the instructions, i.e. apply the epoxy, butt them together, align them, and lock them in place with CA?? Or did you find a way to expose the root ribs so you could clamp them together? I sure with I could clamp them, much as Mike Hammer did on his scratch-built model.

Thanks

Frank

There is really no need for clamping. The way the wing is designed, the center joint does little to hold the wing together.

What is important is:

1) Get a good amount of epoxy on the back sides of the spars where the wing joiner will come in contact with them. I push some epoxy into the pocket at each spar and smear some on the joiner itself before installing.

2) make sure the spars one one wing have good contact with the spars on the other - again, clamping is not necessary, but they should be touching each other.

3) BE SURE TO FIBERGLASS THE CENTER

Lots of people who assemble ARFs ask if they should fibergalss the center of the wing, and I say, "Don't bother" because the wing was designed to not need it.

But the US is designed in such a way that the fiberglass is an integral part of the wing and must not be omitted.

Once again, Mike, thanks so much for the advice, explanation, and details. I'll sure try to do it per your recommendations!!

Frank

Mike,
What did you use to cut out the foam from top of the wing and after it was sheeted? Just an exacto knife? How do you flatten out the bottom of the wheel well? Dremel?

OK. I look at your picture and you glass the bottom of the wing. I look at page 15 of the manual and they glass the top of the wing. If you look at the picture and the alerion controls are on the top. Am I wrong? Do I need to do the bottom of the wing and hollow out the belly pan pieces?

fstevenj - I used a hot bow (For cutting foam wings) to remove the excess, but it was a little tricky - especially doing it alone - because the spray foam didn't cut as easily as regular foam does. If I didn't have the hot bow, I would have probably used a hacksaw blade without the handle. I didn't have to flatten out the bottom of the wheel well because the top sheeting wasn't glued to the foam. So I just cut the circle out of the foam with a hobby knife and ripped out the excess foam with a long-nose plier. Once I got near the bottom, since it wasn't glued to the sheeting, the foam just pulled free

Bernard, both top and bottom get glassed. Then the belly pan blocks go over the fiberglass

Good!

Lots of good stuff, Mike!

What I'm hoping to see soon is details on just how you install and support the wing-mounted servos. The section views on the plans and the explanation on page 34 of the Inst. Book leave lots of questions for me.

Thanks

Frank

Ok, I'll be sure to detail that

Thanks Much, Mike !!!

Frank

Here's a thought for you, Mike.
There was recently a question about the amount of dihedral in the US 60 wing. I got curious and here's my interpretation.

We can treat this as a right triangle with the angle (A) at the root rib, the opposite side (a) at the wing tip, and the adjacent side (b) the distance from the root to the tip. Measuring the plans I find "b" is about 30" and "a" is the specified 1 1/8".Therefore, tan A = 1.125/30 = .0375. From trig tables angle A is slightly more than 2 degrees (2.2 from a simple linear extrapolation).

So, depending on just how dihedral is defined, the US 60 has 2.2 deg. or 4.4 deg (both wings) dihedral. Just as you suggested, much less than 10 degrees.

Frank

What engien would pull the 60 US the fastest? I am thinking of getting one of these but got to thinking about the engine choices that I currentlly have. I tend to go big, really big on engines. I now have a Super Tiger 90 flying great on an US40+ that was lengthened 4" and love it. I know the 90 will pull the US60 but how large and fast could I go?

If your figures are correct (and I have no reason to suspect they wouldn't be) then the Dihedral angle would be the sum of both sides, or 4.4 degrees.

Actually, I did some calculations:

Wingspan = 61.5"

Minus two 1 1/8" wingtip blocks = 59.25"

Divided by 2 = 29.625"

That is the length of one wing panel without the tip.

The dihedral is set by raising each wingtip 1 1/8"

A height of 1.125" over a span of 29.625" gives an angle of 2.16 degrees.

Here's an interesting side note: While doing this, I re-read the manual to make sure I had my numbers right and realized that I only blocked up ONE wing instead of both of them, so I have only half the dihedral called for

Oh well, no biggie