Tuesday, March 26, 2019

Thunder King Tip Panel Dihedral

Here's the latest from Richard Dick on his Thunder King project. He's really worked on the concept of the tip panel dihedral. I measured our Miss Stick and Oly 650 and gave him my results.

In Richard's own words...


Thanks for your dihedral data from two successful models. The Thunder King was originally designed as a towline glider, like the Hover King, and did quite well in contests.

I have looked at RC-Groups comments about the adequate dihedral angle. Several people (actually more than several) referred to using EDA (Equivalent Dihedral Angle) for sizing the angle. So I looked EDA up and it is based on a plot of Moment Fraction versus Semi-span Station. The Moment Fraction is a measure relating to the rolling moment of the wing and has values of 0 to 1. Semi-span Station of 0 at the root and 1 at the tip. So I did the math using the graph and using the 16° dihedral angle and found the EDA is about 10°. EUREKA!

The 16° dihedral turns out to be about 3.75 inches per foot, which close to Thornburg's number. (Editor's Note: Richard and I consulted Dave Thornburg's Old Buzzard's Soaring Book and reviewed his dihedral rules-of-thumb.) Based on my calculation and other people's data including yours, I'm going to slant the tip panels at 16° for the Thunder King.

Attached (are photos of) the wing with both tips spaced up 5 5/16 inches. They are not glued together yet, I just wanted to see what the wing would look like first.

Saturday, March 23, 2019

Thunder King progress

Richard Dick has been working hard to finish the Thunder King glider this spring. Here are three photos of the bare bones. We may soon see this British design fly on this side of the Atlantic.

Wednesday, February 27, 2019

Galler MG 2 Flies Again

Today Richard Dick and I helped (Well, we offered what assistance we could) to Bob Galler. He maidened his MG 2 after an extensive rebuild of the wing. Bob's only flight of the morning was the result of using a 3S LiPo pack. Bob worried about that power but the big model lifted off and was going well at 3/4 throttle.

After a graceful landing, Bob admitted that he would really use a 4S pack in competition.

Congratulations, Bob. You inspire all of us.

Steve Moskal,
(AKA the Comet Kid)

Friday, February 22, 2019

Galler Finishes MG2 Wing Rebuild

From Bob Galler:

Well, its done, using covering materials and wood on hand. And even tho I used cap strips top and bottom I used lighter wood at the tip,  the new wing half is lighter than the old. Jim Correll would never allow that!
The flying will tell. The new wing is the far one.  Need another 4 hours on the electronics back into the fuse and its ready to fly. The weather is not, however.  We are expecting the southern end of a storm tomorrow.  But nothing like Flagstaff!!

Monday, February 18, 2019

Galler Forges Ahead With His MG2

In Bob Galler's own words: "Almost ready to cover. The undercamber cap strip were side strips and took all day yesterday. Electronics to be put back in the fuselage. 
Done this week for sure. Why? Bad weather."

Friday, February 8, 2019

Bob Galler Rebuilds His MG2 Wing

Bob Galler reports: "The lumber yard rebuild of the MG2 right wing half is well underway.  Luckily I Had Some ORIGINAL Ribs AND the, Center Section Of The Old Wing.  So The Tube locations for the joiner rods can match exactly. The left wing half had no damage. And will be used for final tube alignment.