I have my Focus Sport all done except the pull-pull cables and the graphics from Bad Brad. I checked the CG today and this plane is really tail heavy. I would say it's from the Saito 125 being lighter than the YS 110, and the 1/8" wood shims I had to use for the elevator servos. Not much room to add any weight up front and by my bathroom scales I'm alread around 8 1/2 to 9 lbs.

Hi Troy

I thought that's what I said.

The farther away from the hinge line the degrees don't change but the point at which the pointer hits the scale will be different.The farther away the larger the space between the scale divisions must be. IMHO the farther out we can measure the more accurate those measurements will be.

If I told you to use Jerry's device and set everything to 10 degrees and you didn't space the scale out the exact same amount as I did your readings will be different than mine.
This is why Jerry added the spacing device on his unit which I love.

Now if we were to read dirrectly from the control surface then this wouldn't matter as degrees would be the same.

Way back when I built my own airplanes I'd put a tube in the elev halves and each aileron to stick those gadget pointers in and they worked slick.

Dang! Anybody have a conversion program we can use to open up this CorelDraw file on Ron's website?

Troy,

I want to thank you for this build thread - it has been invaluable to me, a newcomer, as I get started in Pattern.

My question is about YS 110 break-in/setup for this model. I was planning on using Cool Power 30% Heli Hi perf., and a 15x10 prop. As far as plumbing - Tetra tank ?would 20 Oz be too much?, fuel outlet with filter on R cowl, and Fuel dot mounted on the bottom in cowl air hole. Thoughts?

Larry

Larry I have been working on it....I just have not done the write ups yet....I have been mounting the engine,a nd doing the plumbing work.

20oz tank is a little large but you will get lots of flight time....I'm going to use a 16oz tank...this is still pretty large.


I'll have some stuff coming...just need to take the time to finish the write ups. I have about 4 days of work on the model that I have photos just have not posted them yet.

Troy

Here are some pics of my Focus Sport at about 95% complete. I still need to add the rudder cables, set the CG, and add the remaining graphics from Bad Brad Graphics. Hopefully I can put the mainden flight on it in a week or so.

Troy in your opinon as a begineer in pattern flying (myself) how far in pattern contests do you think you could go with this model ? Thanks for spending all of this time on building the model and the very informative write ups.

The plane in the right hands is capable of FAI. However as you get into the upper classes, there is an advantage to the larger ships. That being said, it is not required. Jason Shulman won an FAI contest last month with a .50 Era model that his company sells. The workload would be a lot higher, so that is the biggest advantage with the 2M stuff. In the right hands though, this is an FAI capable design with the correct setup.

Arch

I flew Dale Arnold's production version two weeks ago through the P-07 sequence and some of the F-07 and I was surprised. It was very easy to fly and locked in surprisingly well. Great little airplane, I would highly reccomend one to anybody.

Thank you for the reply rcpattern I have flown for about 18 years and I am getting burnt out on 3d and some IMAC so I want to try this.

The contol throws on the Focus Sport are in degree. Can someone convert these for me?

Elevator = 10 degree
Ailerons = 15 degree
Rudder = 40 degree

I was using .017" per 1 degree but it seems so little on the throws.

Angle sine
2.5- 0.0436
5.0- 0.0872
7.5- 0.1305
10.0- 0.1736
12.5- 0.2164
15.0- 0.2588
17.5- 0.3007
20.0- 0.3420
22.5- 0.3827
25.0- 0.4226
27.5- 0.4617
30.0- 0.5000
32.5- 0.5373
35.0- 0.5736
37.5- 0.6088
40.0- 0.6428
42.5- 0.6756
45.0- 0.7071

dreadnaut,

Thanks for the info. My Aeroworks YAK 54 had the throws in degree and inches so I also got a starting point from there. My Focus Sport is finished and the AUW on my bathroom scales looks to be about 9 1/2 - 9 3/4 lbs. 8 oz of that weight is lead in the nose to get the CG spot on. I was looking to get the mainden flight in tomorrow but I still need to set the throws and get some fuel through the engine before it sees any air time. The wing span on my plane measured 63" and the fuse is 70". A lot less than advertised so the wing area of 780 sq in. is not going to be correct so the wing loading is headed up. I hope it doesn't fly as heavy as it turned out.

780 is probably correct. All manufacturers, at least of pattern planes, include the fuselage cross section as part of the effective wing area. You need to consider using some lighter servos in the rear to reduce the nose weight. I think JR 3421SA's would be the ticket. If you get an ounce out of the tail that is like saving 3 in the nose for a total of 4.

When I see the words "Wing Span" and "Fuse Length" I take that to mean what it says. I haven't figured it up but I'll bet the wing area wont be 780 sq in. You are correct about using the JR 3421SA's but it would only save a coulple oz and I'm over weight by 1 1/2 lbs.

Specifications

Wing span - 66 in.

Wing area - 780 sq in.

Fuse length - 72 in

Weight - 7¾ - 8½ lbs

I would be stunned if the lifting area of the fuse isn't taken into account for the wing area of the plane. It actually is wing area, as it is doing work. Also, bathroom scales are very inacurate at the lower end of the scale. What battery pack are you using? Joe is right above, taking just a little out of the tail will help with the balance and allow you get a lot of that weight out of the plane. I'd believe a few ounces over with choice of equipment is possible, but everything I've ever seen from Piedmont is the highest quality and I think every Focus 2 I've seen has come out right at the weight they suggested. I think you will be very happy with the way the plane flies. I would switch to an APC prop though. It will give you significantly better performance, and also would add useable weight to the nose.

Arch

Zippi

I am not aware of a wing area calculation which does not include the "fuselage area".
My understanding is that that (fuse area) is included by definition.

Also, wing span is ALWAYS tip to tip ready to fly. Full scale and model.
Fuselage length is from the tip of the spinner to the aft most part of the rudder. It certainly isn't from drive washer to rudder hinge line.
A good example would be the measurements taken on the current 2 meter pattern planes/FAI rules.

BTW the actual difference in weight between a Hitec 5645 and a JR 3421 is 1.07oz. Going from the C/L of the rear servo location to the CG = 36.5". therefore the total calculated 'weight/balance' is 1.07x2 (two servos) = 2.14oz X 36.5" = 78.11ozin.

Using the CG to front of firewall measurement -11.5"- and dividing the total oz.in. difference 78.11 by 11.5 we find that to balance the increase of 2.14 oz. in the tail we will need 6.79 oz. of weight in the nose.
Adding it up we have the difference in servo weight (2.14oz.) plus the nose weight to counteract it (6.79 oz.) which when added together yields a total weight increase of 2.14 + 6.79 = 8.93 ounces.

Therefore you've got a total A/C weight increase of 8.93 ounces due to your rear servo choice alone (also the stand-offs for the servos are unnecessary with 3421's).

That alone is 1/3 of the total "overweight" you've mentioned. [&o]

Now we can do the same thing for your choice of aileron servos times their moment etc. etc. and come up with even more weight.

These calculations are admittedly crude but they do emphasize the point that it isn't "just the weight" it is where the weight is located.

I'll bet all the concern will vanish when you get her trimmed out-----

I think I've already said in one of my post that my plane is over weight do to the shims, servos, and the Saito 125 weighing less than the YS 110. As far as the wing span and length, my plane measures like I said, 63" from wing tip to wing tip and the fuse is 70" from the end of the rudder to the tip of the spinner. Weighing the plane with my bathroom scales is all I have and yes it is a crude way to get the weight but thats what I have and used. Thats why I didn't give an exact weight. I think rcpattern said something about Piedmont models being of the highest quality. Maybe I just got a bad one but my fuse was twisted, I had to sand the wings down to fit the fuse, the rudder was to long, the wheel axles were way to short, when I got the plane there was no packing inside the box and everything had been slamming into one another and there are dings and impressions on the fuse where the landing gear had been hitting it. I emailed Piedmont models twice and got no response so I gave up. Lesson learned. Like I said, maybe I just got a bad one but it will be the last one. I did run about 4 tanks of fuel through the Saito 125 today and everything is good to go. I have my hopes up and looking for an enjoyable maiden flight next weekend.

It is a little late now, but you could have used a [link=https://www.unitedhobbies.com/UNITEDHOBBIES/store/uh_viewItem.asp?idProduct=4308]Bellcrank[/link] and reduced your servo tail weight, since you chose a lighter engine.

Later,
Omaha

Omaha_RC_Flyer,

You are correct. I guess there are a lot of "If I would have" but like you said, it's a little to late now. It would have been nice if the manual would have meantioned the need for low profile servos because of the narrow fuse and the thin wing. We are getting hammered with rain and it's going to be all week but if the weather is clear this weekend I'll be able to get the mainden flight in.

This is my first pattern airplane. Can anyone provide some guidance on setting up the pull-pull rudder, (linkeage, considerations etc.)?

Larry

lbleduc,

I used the [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXEVW5]Great Planes Deluxe 4-40 Pull-Pull System [/link]. After I got the rudder servo installed I ran one cable down the fuse by using fishing line and a lead weight on the end. I hooked up the cable on the servo end first since it's easier to work on the rudder area rather than inside the fuse on the servo. I put tape on the rudder to hold it straight while I hooked the cable to the clevis on the rudder. Get the tension snug but not to tight as it will make the servo buzz. Install the other side in the same way and once both sides are connected turn your radio on and center the rudder and adjust both sides if needed so they are snug and the servo is not in a bind.

disregard

It was really windy today but I was able to get one flight in on my Focus Sport. The control throws per the manual were a little to much on the Ailerons and made it really touchy. The Rudder was to much as well and made ground handling a job to keep the plane straight down the runway. The Elevator seemed ok. The plane seemed to track very well inspite ot the gusty wind conditions. The Saito 125 looks like its going to be fine on the business end once I get it broke in and leaned out all the way. Today was a very rich run but it did very well. After I landed I noticed that three of the four 1/4" by 7/16" blocks that the cowl is secured to had come out of the firwall. Very little glue here and I guess I missed getting some epoxy in this area. I noticed three balsa sticks about 3" long with some foam on each side laying in the fuse that had come loose from the tail section inside the fuse. I'm not sure if this will be a problem or not but after only one flight the plane seems to be coming apart. It was so windy I'm not really sure how the plane performed but I did have to add a lot of up elevator to get it to fly level so maybe soom of the weight I added to get the CG spot on can slowly be removed.

Glad you were able to get in a flight------even if it was too gusty to give a reading on the A/C's performance level.

The airborne disassembly notes are disheartening to those of us with F/S's still untested.
Trust me I shall now try to beef up the cowl mounts and take a critical look at some other things as well.

I certainly wish Troy could finish his build notes and a flight or two of experience as well.