Blazer1

My Feedback: (1)

I am in the process of building an Ultra Stick 40. The two other planes I have built I have purchased a radio which came with servos (JR Sport ST47's) that I used, this will be the first plane I can choose my servos. I am happy with the performance of the JR ST47 servos but if there was another servo that offered increase performance at a similar price I would of course purchase it instead. As it is now, I will be using JR Sport ST47BB that can be purchased for roughly $13.00, is there another servo to consider for less than $20 or so? I have also thought about using the cheaper servos on throttle and rudder and better servos on ailerons and elevator, is this a good idea and what do you recommend?
Thanks!

da Rock

One of the deals for servos that go in the wing are the Hitec HS225s. They're only slightly over the $20 mark, but only a little. And they really have a couple of unique things worth the couple of extra bucks.

They're considered to be mini servos. Matter of fact, they're called The Mighty Mini. So they're just a bit smaller than the average Standard servo. Turns out they're also only 3/4oz each. And a lot of standards are 1.5oz each. That's significant. That often isn't really important, but is significant difference in weight. And what makes them stand out, is that their torque is better than most Standards. Amazing thing nowadays. Something that actually is lighter and more powerful.

I've got a number of models with 'em in the wings that've flown a lot since 2005, when I first stumbled on them. A year or so ago, I had a 60size that was going to be "overweight" and I stuck them in for all the functions. 5 servos saved me almost 4 ounces in that sucker. It flew great, and why not, they're stronger than the recommended standards.

Blazer1

My Feedback: (1)

Thanks for the tip da Rock! Is this the one?[link]http://www.horizonhobby.com/Products/Default.aspx?ProdID=HRC31225S[/link]
Will it mount in the factory location without much modification?

PipeMajor

My Feedback: (1)

If you opt for the 7 servo US40, then consider the Futaba S3004 - a std sized ball bearing analog servo which offers 44.4 oz-in. of torque at 4.8v and 0.23 sec/60ΒΊ speed with an all-up-weight of 1.3 oz. It's available for under $15 per servo.

Blazer1

My Feedback: (1)

After much thought, I did not use the quad flaps. I am still not sure I did the right thing. Being a new pilot I felt it would be too much.

PipeMajor

My Feedback: (1)

If you change your mind you can always purchase a replacement wing and assemble it with the quad flaps. Then you'll have virtually two airplanes. My US40 was assembled with the quad flap arrangement.

Blazer1

My Feedback: (1)

That was my thinking, I could always do it later.

Blazer1

My Feedback: (1)

Okay, how about this servo setup for a light weight Ultra Stick 40;

Ailerons and elevator= [link]http://www.horizonhobby.com/Products/Default.aspx?ProdID=JSP20040[/link]

Throttle and rudder= http://www.horizonhobby.com/Products...rodID=JSP20030

pumbadog

I have the 60 size stick and built the wing with flaps. It's rare I ever use them. It basically turns it into a kite. I have another wing, I'm just dragging my feet on building it ailerons only.

Blazer1

My Feedback: (1)

Come on guys, help me find some servos.

PipeMajor

My Feedback: (1)

I'd stick with standard sized servos for any 40 powered aircraft. Besides, the precut openings are sized for a standard servo. If you use a mini or micro servo, you'll have to do some additional modifications to install the servo.

da Rock

You already found them. Those you've listed will work great. Any that produce the torques those produce will do just fine.

Charlie P.

I fly Futaba and Hi-Tec. I've got six S3004's and an HS645 for the rudder in my Goldberg Hot Stik; which is just a faster & lighter Ultra Stik. ;-) Toss in a bunch of S3151 digital servos if you need an excuse to spend more money. Even with these I have to mix in some exponential and set 50% low rates or I can't make fine stick corrections for smooth landings. No one wants to see a plane land looking like it's doing the Australian Crawl swimming upstream.

Proper linkages can make as much difference as increased servo speed and torque. Set her up tight and stiff on the linkages and it's much better than adding speed and torque on the servos.

There are a couple fliers I know who might pick up on a 0.19 vs. 0.21 second sweep of 60ΒΊ and benefit from it. I'm not there yet.

bigedmustafa

My Feedback: (2)

I recently posted a poll in the RC Radios, Transmitters, Receivers, Servos, Gyros forum asking everybody what their favorite standard servo was, and the results were quite interesting:

http://www.rcuniverse.com/forum/m_7261321/tm.htm

The Hitec HS-425BB was far and away the most popular servo mentioned. It's commonly available for $14.99 and boasts some pretty impressive specifications for a $15 standard sport servo:

Motor Type: 3 Pole
Bearing Type: Dual Ball Bearing
Speed: 0.21 / 0.16 sec @ 60 deg.
English Metric
Torque: 45.93 / 56.93 oz.in (4.8v/6v) 3.3 / 4.1 kg.cm
Size: 1.59" x 0.77" x 1.44" 40.60 x 19.80 x 36.60mm
Weight: 1.60oz 45.50g

da Rock

The HS-425 is a good value. And a great servo.

Hitec has another excellent value at about that price. For $16.95 from Tower, the HS-475BB has

61oz.in @4.8
.23 sec@60deg
1.4 oz weight

Hitec has some good servos! at good prices!

danny31292

Running 6 volts will give you a huge speed and torque improvement for no extra money.

Blazer1

My Feedback: (1)

I see that some of the servos listed have higher torque figures with lower speed ratings than the JR Sport ST47BB I am leaning towards using. I would assume(keep in mind I am new at this) that with a small, light plane such as the US40 I would benefit more from higher speed, less torque servos? I would assume 40oz. or more of torque would be plenty for the small control surfaces of the US40? I was all set on going with the Hitec HS225s that da Rock suggested but I would rather find one that fit the factory location without modification. I will be powering this US40 with a Saito 56 ,which is on the small size, so I am trying to build light!