Prop Choice

I am new to this hobby. I bought a used Ultra Sport low wing complete with Futaba radio and Super Tigre .46 engine. I took everyones advice from this forum and have learned to fly on my brother in laws trainer. I just soloed last Saturday. 5 Take offs and landings. I know I am not ready to fly my Ultra Sport Solo but I am looking ahead. Currently my Brother in Law flys my plane while I learn on his trainer . It has been a good situation.

Now to my question. Currently my plane has a 10X6 prop. I was thinking of trying an 11 X 5. Any opinions on whether this is a good idea, bad idea or really doesn't make much difference.

Thanks for any and all advice.

Ray Crane

Reply to
Kat3595
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an 11/5 would give you a little less top speed but more vertical pulling power. I have flown a TT46 with a 12/4 prop and it worked fine. I like APC props, but for safety, as a novice, I would suggest a wood prop. They tend to wack your fingers pretty good, but will often break if you really get into the prop with your hand. The "plastic" props won't. Recheck prop tightness often.

opinions will vary, JK

Reply to
jnkessler

It would probably be easier to re-attach a finger cut off by an APC prop because it makes a clean cut. The wooden prop would probably tear the finger off stretching tendons and making it harder for the doctor to re-attach. Best bet would be to go with a prop made of nerf foam.

Back to the serious question, adding diameter will improving pulling power, while reducing pitch will reduce top speed. The extra diameter will act like a wind brake at idle allowing you slow down a little more during landing. Use a tachometer and measure your rpms with different props, you might be able to get a 11x6 to work

Reply to
Normen Strobel

If you want a quicker take off and better vertical performance, then yes you will love the 11X5. However you will sacrifice some top end speed.

Kat3595 wrote:

Reply to
S. Boucher

Ray, the 11x5 or an 11x6 would probably be the prop of choice for the ST 46. Please don't become overconfident! The Ultra Sport is a pretty hot airplane for a newbie. It's fast and agile, and will be quite different from the trainer you're flying now. Some things to look out for:

It's a low winger. You'll have to train your eyes because it'll look like it's flying upside down at first.

It's a go-where-you-point-it plane that won't automatically level itself like a trainer does.

As stated before, the Ultra Sport is pretty fast and responsive. It uses the same wing and some other parts as the Kaos, an old pattern design. Things happen quickly with planes like these, and you won't have time to think about what you need to do next in certain situations. Work on that trainer and practice all the maneuvers it's capable of doing till controlling till it becomes automatic. Then, you can enjoy the Ultra Sport's quick, crisp performance without it scaring you.

Finally, the Ultra Sport could be built with either trike or tail dragger gear. Since most trainers are trikes, you may have another thing to learn if your US is a tail dragger. Tail draggers take a bit more finesse on the ground than their trike counterparts.

Keep working on that trainer and get the basics down pat. Then, your Ultra Sport will be a blast to fly!

-- Morris Lee snipped-for-privacy@verizon.net

Reply to
Morris Lee

Ray,

11x5, 11x6 sounds right, as the previous respondent indicated. You will be delighted with the US, once you get to it. But I also agree not to rush into it too soon. If you just soloed, my $0.02 worth is to get several more hours of stick time on the trainer, until the flying the trainer becomes absolutely second nature. Compared to the trainer, the US is fast and responsive and will not be very forgiving with wrong commands or hesitations, so take your time.

The US40 happened to be my 4th airplane, after a couple of trainers and another uninspiring aiplane, wich I had been flying for a few years. I remember my first US flight, after I trimmed it and relaxed a little, was like a religious experience. I had rediscovered flight all over again. The plane was truly a pleasure, very responsive, any trick in the book just by asking. I enjoyed the US40 so much I went on to built a US60 with as ST90. To this day, this continues to be my all-time favorite airplane, even though I built others since then.

Good luck Bob

Reply to
Bob Merlino

The Ultrasport can also be a very forgiving plane when not screaming through the air. Its heritage can be traced back to the Chaos , KAOS and Ugly stick lines. It uses the same basic airfoil and has all the easy stall characteristics of its parents.

Reply to
Paul McIntosh

Thanks for all of the input and rest assured I am not going to rush into the low wing. But a second question is what problems (if any) do I need to watch out for if I try different props? My thinking is that maybe for the cost of a new prop I can get the feel of flying a different airplane. I see on the Tower site that a 10-8 is a recommended prop for this engine. If my thinking is correct it would make this plane an absolute screamer. But an 11-6 or 5 is also recommended. Do I need to worry about any engine damage trying different props etc? Thanks again for all of the input.

Ray

Reply to
Kat3595

My US 40 has a Thunder Tiger .45 with a Macs tuned pipe.

During initial flights many prop brands and sizes were tried, and I found the APC 10X8 to be the best overall for my style of flying. The TT .45 (BTW it's the original one and not made anymore) is happiest when turning a lot of RPMs, hence the smaller prop choice. I had tried several 11" and even a 12X4. Very little prop to ground clearance with 3" wheels and the stock wire gear with that 12" prop.

With the APC 10X8, and a light model (it was a kit - came in just under

5lbs) there is no lack of performance. Unlimited vertical, and, if everything is just right, knife edge loops are possible.

My point is, don't get settled on a prop choice before you try several with your engine and flying style.

I'm sure you'll enjoy the Ultra Sport as it's a great design and flyer.

Mike

Reply to
Mike

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