Time to start something completely different. The BMJR kit of the Zaic Thermic 50.
From the BMJR website
Check out those prices!
The Thermic 50 should make a nice electric. I happen to have almost all the RC and electric gear needed to fly her at the SAM Champs. (I wonder if someone somewhere has the plan for the pod and boom Thermic 50-X pictured above?)
The Comet Kid
I'm so glad Richard Dick was able to maiden his Thunder King glider on June 1, 2019.
Richard Dick and Thunder King; Photo by Bob Galler
Here's Bob Galler's report of the successful test flights.
"Yesterday at an almost completely empty Balloon Fiesta Park (not normal for a Saturday), Richard maidened his scaled-down Thunder King. It flew right off the building board with no adjustments needed for our conditions- 5 to 10 mph from the south. It came off the hi-start just fine for that wind. It looks great and flies great. We hope to see it in Boulder City."
And now the report of Richard, the master builder.
"I maidened the Thunder King this morning with Bob's help. A hand toss showed it should glide pretty well. Then we tried a few hi-start launches and those flights went very well: I even caught a thermal on the last launch. The model weighs 29 oz at a CG of 40% . It's a little heavy and so it will require a strong hi-start in no wind conditions. However, there was a 5 - 10 MPH wind this morning and it launched very nicely. It flies fast being that heavy."
Our friend Larry Jolly has really started something with his push for Old Timer gliders as a SAM event.
Sailwing 100. LE at 30 deg. Spar 1 at 28. Spar 2 at 25. TE at 21. All ribs at 21 to TE in notch. Rib 1 at 3 degrees inward. Now to mark for wing joiner tubes. Only first 4 ribs. But cut and drill mirror opposite wing at same time so all line up. Then take apart and drill and reassemble. Or its never right. But I love doing it. The warm up for the Fillion Champion!
The first is Jack Hiner launching a JETCO Imperial by Don Ellis. Don and Jack were early members of the S.O.A.R. Club in the Chicago Metro area.
Don and Jack are dressed for those brisk midwest conditions. Here's Jack's comment "Reminds me of a SOAR member Don Eliss (spelling) a WW II vet who stretched The Imperial from 100 to 120-inch span. A great flyer with me launching for Don in this photo in the 1970s. A cold Winter day. Don with hat and gloves. Much younger me no hat or gloves."
ASA Club member Tom Tichy acquired this Imperial and modified it for electric power.
Club member Bob Galler notes " Tom Tichy restored and added electric power to this 1959 Jetco RC 100 and flew it today. Flew fine."
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.
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.
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!!
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."
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.