At last October’s Ringmaster Fly-a-thon day at Wrentham, the hit of the show was not a Ringmaster. Instead, Bob Gost brought one of the craziest airplanes (and I use that term very loosely) I’ve ever seen. His “Roll Out the Barrel” is unique to say the least. It’s got a fairly standard profile fuselage, but the “wing” is something else. Made from empty tin cans (and nothing else), the plane doesn’t look like it should fly. Bob said the plane was inspired by another “flying can” that his friend, Bob Yeomans, built back in the ‘50’s. They were both members of a West Haven, Connecticut club that referred to themselves as the “flying idiots”. Bob Gost said that Bob Yeomans was the best all-around flier/modeler he ever met and wanted to honor his old friend with his version of the flying can. Bob Yeomans used 2 rectangular fuel cans for his wings. Bob Gost did him one better by adding round juice cans outboard of the rectangular cans and powered it with an LA .46.
At the field, Bob asked for volunteers to take the maiden flight with “Roll Out the Barrel”. Remember, the plane doesn’t look like it could fly, so there was some apprehension, but finally Dick Carville volunteered and to everyone’s surprise, the plane flew. At an estimated 20 – 30 degree angle of attack in level flight, it’s not going to win any stunt contests, but that it flew at all is amazing. Warren Dillman posted a video of the flight and it can be found at: https://www.dropbox.com/s/uo97hakktxeq1l5/VID_20171007_115514046.mp4?dl=0
Bob graciously sent me the plans for “Roll Out the Barrel” in .pdf format. If anyone is interested in obtaining the plans, please let me know and I’ll email them to you.
Ara Dedekian brought a large, stunning blue biplane to the Brunswick Area Modelers fun fly in Topsham, Maine last August. The plane was built by Dave Slagle, who is an icon in model airplane history. This version of his “Bippy” is powered with an OS .70 four stroke engine that incorporates throttle control via an R/C 2.4 Ghz system. Ara flew the plane on 100 lb Spectra lines and he says that he’s done loops, wingovers and inverted flight with it. I asked about how hard the plane pulls, and he responded that the line tension is quite reasonable. The combination of the throttle control and the very light (stick and tissue) construction techniques used by Dave results in a stable and easy to fly plane. Ara indicated that Dave is building another control line “Bippy” that he plans to power with a massive 1.2 cu in four stroke engine. I think that the throttle control will be a very welcome feature!
Don Coe brought his new red Nobler. He was having some trim issues with the plane so we made some adjustments and got it flying pretty well. Of course, when we felt it was flying satisfactorily, fate stepped in and the line clips caught each other and the plane crashed. This was a great example of why staggering the lead outs is a good idea! Fortunately, the damage wasn’t too bad and Don has completed repairs.
The Brunswick Area Modelers are primarily an R/C club, but a few of the members fly control line too. It was very gracious of the club to host the fun fly and they also provided a great grilled lunch for all.
Last weekend, we drove down to Wrentham to get in the first flights of the season. Dick Carville and Rick Campbell were already at the field and Warren Dillman and Leon Bowman stopped by later. The weather, while predicted to be warm and calm only a few days before, turned out to be cold and windy. It didn’t slow us down and we all put up a bunch of flights. It felt good to dust off some of the cobwebs that the 5 month winter layoff produces. Dick flew the maiden flight of his new Humongous and Rick Campbell flew his newly electrified Saturn.
I thought I’d share with you the results of a small experiment I ran during the building season. I built a new Saturn and during the build, I decided to try and quantify the effect on fuselage stiffness that the diagonal bracing inside the fuselage (from the wing back to the stabilizer) had. The fuselage sides, formers and molded lower skin had already been glued together and the stabilizer glued to the fuselage. A 2 oz weight was applied to the tip of the stabilizer and the angular deflection caused by that load was measured.
The angular deflection was measured after each diagonal brace was added. The diagonal braces were made from two 1/16” thick by 3/8”wide pieces of balsa, glued together into a “T” structure. Measurements were taken with the load placed on the inboard tip of the stabilizer and also with the load applied to the outboard tip.
Brace Deflection (I) Deflection (O)
0 1.15 1.3
1 1.05 1.2
2 1.05 1.0
3 0.7 0.55
4 0.6 0.55
5 0.55 0.35
6 0.4 0.4
As can be seen in the above Table, the deflection of the non-braced fuselage was 1.15 degrees when the inboard tip was weighted and 1.3 degrees when the outboard tip was weighted. At this point, the fuselage felt quite flimsy. As each diagonal brace was added, the defection of the stabilizer reduced (within measurement error). With all braces installed the deflection was reduced to 0.4 degrees. At this point, the fuselage felt much stiffer. The added weight of the braces was 0.15 oz, and seems a great amount of stiffening for a very modest weight gain. I measured the deflection once more after the upper molded skin was glued to the fuselage (completing the box structure) and the fuselage was covered with carbon veil. The deflection was further reduced to 0.15 degrees. I don’t know if this really tells us anything other than diagonal bracing is a good idea, but it was a fun experiment to perform.