sigrun

Work in progress. Scratch builds X2. From my stocks of SIG comp, Guillow, & English birch ply, all pre-weighed. Guess the model?

Prefer 2" aluminum brass bushed bellcranks by Perfect in this application. From previous experimentation, the design flys even bettter with operational flaps,. I won't be including them in these builds as built light, they turn sufficiently tightly without.

vertical grimmace

My Feedback: (1)

Well the title of the pic on photobucket called it an Akromaster, so that would be mine!

The numbers on my little 1/2 A combat model is 305 sq. in. and a flying weight of right at 8 oz. On 42', .012 lines, they go around 80 mph. So that is pretty quick, and I have been told the lap times are similar to modern FAI models, with the hot modern .15's. FAI is actually the most popular class now. A lot of this has to do with the availability of ARF aircraft from the Chechs and Russians. In Fact, most of the planes you see at the speed limit meets are used FAI models, and the companies that sell these are offering Speed limit designs now. I have never been a fan of short tail moment aircraft. Those tail flipper, euro models do not point well. Too short coupled. From talking to many pilots at the last combat meet I attended, many felt the same way, but it is still what they choose to fly. But, the Russians are putting out some longer fuselage, tail sections on the new speed limit planes. Probably from requests. So, to have a longer tail on my 1/2 , I incorporate sweep. But, the tails on the model in my pics was too long, and they were tail heavy. I have since cuth them down a bit, but still need to test fly them.

paw080

Hi Vert, I really quit flying Combat when AMA changed the 1/2A Combat lines to 42'. This was to accommodate the "new" 1/2A Foras etc.

that lapped too quickly at their higher flying speed. The paradox is that they do not lap any faster on 42' lines than "TDs" did on 35' lines.

My TD ships were capable of flying 75 mph which was okay for my adolescent sons, but were lapping too fast for me. I slowed my models

down to 72 mph, which I was capable of controlling. My TD models were 195sq" enlarged 1/2A monbooms, they had foam LE with built

up balsa and spruce construction. They weighed 4.9 - 5.1 ozs ready to fly sans fuel. One of my sons was flying Barry Baxter 200sq" Phoenix

wings(4.5ozs). I built one way out of the box 1/2A Combat model that had a double tapered wing with boom and stabilator(sp?); it was also TD powered,

It had a shocking 270 sq"s of wing area and weighed 5.2ozs RTF sans fuel. It could lap at 68mph and turned 6' diameter loops at that speed.

I have never seen another Combat design that could turn that tight losing losing such little top speed. The design was of course fragile and lasted

only three Combat rounds(my son was flying). He scored three kills in arrow, but the last opponent was killed so fast he didn't realize the match

was over and bellcranked my son's model just as the match ending horn sounded. That model had a 12% thick wing; which allowed such a high

speed for what is considered a "Floater" design. I remember thinking at the time that with the new engine's power capability, I could build a 370-390sq"

design and still fly the model on 35' lines. The speed would match the TD lap times, but the models would turn much tighter than the TD contemporaries.

I'm significantly older now, deefer and blinder. I just hope to still be able to ride my "Old Man's Sport Bike" for a bit longer.

Tony

vertical grimmace

My Feedback: (1)

Yeah, 370-390 would be too big for a modern 1/2 A, (keep in mind the famous Voodoo was 360) even though that may sound good. You still have to be fast enough to keep up with the competition, but balance that with turning. Thinning the wing helps with speed for sure, but the ability to turn is important for sure. My old .36 powered fast designs have around an 18% airfoil, but my 1/2 A is around 12%. This was done to keep the speed up. I can tell you this, you may think 8 oz. is high for all up weight, but I have not seen any model that can turn with this new 1/2 A, and at the last contest I had 4 inquiries for kit availability. A competition model is like balancing all of these factors on the head of a pin. One of the things that makes this aspect of the hobby so much fun. It is missed by so many in the other disciplines. And for the record, this is the type of model I fly mostly, just to maintain some perspective!

BrightGarden

Can someone point me to a recent guide on RCU about constructing the leadouts, connecting lines. I have accumulated a few sets of lines and a few c/l planes but want to make sure I am abiding. Great info on this thread.

vertical grimmace

My Feedback: (1)

Under the general CL section of the AMA rule book, they have examples of what proper terminations should be used. Also, if that does not help, I would shoot Brodak an email, and I am sure they will have a schematic of either a wrap, or a crimp.

vertical grimmace

My Feedback: (1)

Here is a link to the General CL guidelines by the AMA. https://www.modelaircraft.org/files/...6CLGeneral.pdf The is no doubt that you want to make sure you use proper terminations, otherwise you can be sure it could result in a crash.

vertical grimmace

My Feedback: (1)

Here is a Sig Akromaster I have been working on. I lengthened the tail, and changed the fin/canopy. Think of it as a "Fancherized" version. Like the typical mods done to the Twister. I fiberglassed all wood components with laminating resin thinned. The covering is lightweight Dacron, think Sig Koverall here. Has a couple of coats of dope. Engine will be an OS .15 fp. I increased the wing area with the flaps, which I made functional as well. This was a mod I found recommended on the Stuka stunt forums. The guys mentioned that the plane flies good under 20 oz. I am at 16 oz. right now without the color dope yet, so I think I am good. Should be a fun little plane. Color dope on order. Should fly in about a week. 52' .015 lines.

t587y28

I have OS 15LA Engines NIB and OS 15LA NIP Parts that are Marked Made In China?
I would like to find out any info about COO, current manufacture of the OS 15LA Engines ?




Thank you very much,


Gene




I recently purchased several OS 15LA Engines from Tower Hobbies and all are Made In Japan.
I also purchased 2 EA OS 15LA Engines from Graves RC Hobbies, Orlando, Florida, both are Made In CHINA ?


I was concerned that the 15LA Engine was going to be discontinued, like the rest of the LA Engine Line.
This was my origial reason for stocking up on this engine.
I have OS 15LA Engine Parts that are Marked Made In China, and some of the same parts Marked Made In Japan.
I have OS 15LA Engines NIB Made In China?


I am going to check to see if they all interchange.
I am going to disassemble one of each made in Japan, China Engine to inspect each part, and to check for cleanliness.