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General control line discussion => Open Forum => Topic started by: Matt Brown on June 23, 2020, 02:45:28 PM
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ST 60 with tongue muffler, SV11 arf. Is 6 oz tank big enough to comfortably fly the complete pattern? I want to try a plastic tank but biggest I have is 6oz. I can order in a 8oz but it will take a week or so to get in and I was hoping to fly it this weekend.
Matt
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Depends on the size of venturi and weight of the plane.. Anything over a .260 or so and you'll need a bigger tank. Even that will be close.
I flew with Pat Johnston in Boise, Idaho for a lot of years. Elevation was about 3300 feet and temps over a 100F in the summer. Using a .320 venturi on an ST .60 with a 13 inch prop, took most of 8oz to get through a pattern. Same setup at sea level only too about 7oz.
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I better play it safe and wait on an 8oz.
Thanks, Matt
Or make the 6 oz easily replaced!
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If it is easy to swap tanks then you need not waste a weekend. Pop in the tank you have and use flight time that tank gives you to trim the airplane and get a feel for how the airplane flies. It also give you opportunity to see if you have a good engine prop combo among other things. At the very least it will give you an Idea how to proceed when the new tank arrives. Of course you will have to adjust the trim for the weight of the additional fuel in the 8 oz. But you will have an Idea where the trim is going to wind up.
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Matt,
Peter is right, get out there and fly the airplane and work on trim while you wait for the tank. While not exactly the same, I fly electrics with a single lap between maneuvers and can get a pattern in within 4 minutes. While I don't have to deal with fuel load and balance issues with electrics I think you will find the practice helpful. Besides, I am sure that you will want to feel the airplane out and not necessarily doing a pattern on the first flight. Good luck and happy practicing.
John
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Stock venturi or a restrictor with the spray bar through the venturi?? Make s a difference. I have a T&L ST.60 in a 60 ounce model that lets me run a 13-5 Xoar and spin it up a bit and I'm in the 5 ounce range in the midwest summer. If you are heavier and need a 6 inch prop, it gets dicier.
Type at you later,
Dan McEntee
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It is a new ST 60 that Randy reworked. He put in one of his venturis and NVA. It is the one with the spraybar in the original case cross hole.
I was thinking of trying a Brodak 13-5. A Xoar would be worth a try also.
My other SV11 arf is 63oz with K77 and full pipe. I’d think this one may be a little lighter.
Matt
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It is a new ST 60 that Randy reworked. He put in one of his venturis and NVA. It is the one with the spraybar in the original case cross hole.
I was thinking of trying a Brodak 13-5. A Xoar would be worth a try also.
My other SV11 arf is 63oz with K77 and full pipe. I’d think this one may be a little lighter.
Matt
They came from the factory with a true venturi like Randy sets them up with. At that weight, you might be fine with a 6 ounce. You can even drop to 5% nitro if need be. I had some posts over the years about experimenting with props for the ST.60 in a 72 ounce Cardinal and what worked and what didn't . I managed to fins a few of the elusive Rev-Up 13-6's, Zinger, and Brodak 13-6 props, and the Brodak is what got me the closest to what I was looking for. Then I read Allen Brickhaus' mention of the Vess prop in his column in Flying Models and got a few. It was the best of the lot at that point in time! The ST.60 just makes a special growl when it's happy with the prop it has on it and the Vess woke it up! I'm not a big fan of the scimitar shape but if it works, I'l go with it! When I got this model I am flying the same ST.60 in now, the Xoar brand came on the scene and I put them right there with the Vess. They make a plastic prop that does OK also but it is under pitched a bit, more like a 5 than the 6. I even tried a three blade Master Airscrew 12-6 (which is also more like a 5 pitch) and it has some promise if you like that three blade look. The MA props can be repitched also if you need to. Have fun with your Tiger! It's like old Tony says, "They're GRRRRREAT!!"
Type at you later,
Dan McEntee
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The P.D.P. , with the concave head fins ( and the last of the prvious 4 window ones - shine a flashlight up the zorst port & look ) use less juice ,
so there you might get away with it .
IF it is one of these .
In the Patternmaster Tapes , theyre SAYING Jose was running a 13 - 4 , to control the wind up , in a LJ .( N-30 section ) . So appears feasable .
Unless it was Pre Nats misslead the opposition propaganda .
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All mine are gas hogs, Be safe with eight.