I have a CG Ultimate ARF. The specs say to set up for so many degrees of control throw. That's cool, but my guage is in inches or mm.

Anyone have any measurements they can give me for a maiden flight. I realize I will end up tuning to my taste but this is my first big plane and having been flying helis for 8 months I am a little intimidated by the scale of this thing.

Thanks Y'all,
RCA

Hey RCA,
I have the same problem - I haven't set my throws yet, but I went to Office Max and bought a cheap plastic protractor (a scale that goes from 0-90 degrees. I think it cost about a buck.

I hope this helps.
Jim

I used a protractor and drew extended lines (on some paper) showing the throws from the book. I made the surface look like my drawing. After a few flights I set them higher. My elevator was about 1 inch. The rudder was elevator to elevator. The ailerons were all I could get with some expo. This set up gave good response without always looking to snap under a load.

Without expo, I'd set the ailerons at about 60% of available throw.

Cool!

So for maiden flight I will try:
Elev 3/4"
Ail 1/2"
Rud 1 1/2"

Does this sound about right?

My Ultimate will have a saito 1.80 in it so I am kind of being carefull with it. I haven't flown such a big bird with this much of a stump puller for an engine. When I broke in the engine it was moving the bench. It should pull the plane around no problem.

Word of the day: Trigonometry.

Actually, I'm just setting mine by eye. I have some experience with this bird though. I think the throws you listed are a little aileron heavy and a little rudder light. I like about 3 inches of rudder and enough aileron for one roll per second.

Mine is totally ready to fly, but the weather won't cooperate. I'm jones'n here.

Good luck on your maiden flight.

Thanks for the info.

I am iced in here, too.

I have been putzing with it off and on all day.

All I have left is balancing, top wing mounting/aileron connections and canopy mounting.

I need to find a pilot, also. I doubt I will be able to get out to get the rest of the stuff I need though. My driveway is at a steep angle and no one has driven down the alley. Don't get me wrong I can drive in the ice. It's the other idiots that I worry about.

At minimum I will run a couple of tanks through it to get some flight time estimates.

The neighbors are gonna luv me.

I hear you on the weather thing. I'm in Wisconsin and still under a foot of snow. I fly the Zagi a lot.

For your throws, I do fly a lot of aileron. Other good pilots in my club have taken the sticks and commemted on the "CRISP" aileron response. You may want to back off a bit, or add some expo to start off with. I also agree on the light rudder throw. This plane has one of the best rudders in the hobby, use it. Start off with 2 1/2 inches and work up to all but touching the elevators.

How is balancing the Saito going? Unless you moved servos to the tail, you'd better go buy some lead. My Webra (31 ounces with a muffler) took 3 ounces in the tail to get it to balance by the book. That was with the Rx and battery under the canopy. And I still feel the CG could have gone back quite a bit more. If I did another, I'd put the servos in the back.

Good luck, keep us up to date.

I actually overcompensated for my Saito 120 installation. I put the servos, battery, and reciever just forward of the former that is directly behind the wing. I had to add a small hatch aft of the wing to acces the equipment in this location. It ended up balancing right at the aft limit of the range. I then moved the battery and reciever to about the center of the bottom wing. It now balances 1/4 inch aft of nominal. That should be a good starting point. I always end up moving the c.g. aft to get a more "honest" flight characteristic.

I think the book's CG is quite conservative.

I'm tempted to do another Ultimate. I might look into the Dave Patrick. The Goldberg with the Webra was a bit over powered. It was fun, but a little larger plane would have been more suited to that kind of power.

Dry it will balance on the forward suggested CG. If I move my RX battery pack (5 cell 1400) behind the wing it balances to the aft suggested CG.

I will do maiden on the forward CG so I can get the feel of it without the fear of stalling it out.

Do y'all balance dry, wet or at half tank?

All of my radio gear is in the stock location. I mounted my engine as far back as I could and trimmed all the excess material I could from the cowling. I am running a Slimline Pitts style muffler that exits under the cowl and the engine is oriented with the head to the right side.

I upgraded the tank to a 20 oz version in the stock location with reinforced supports. This is due to the fact that on breakin a 10 oz tank was lasting about 3 minutes with the 16x10 zinger prop I was running.

Thanks all for the input. It really is helping me out!

Hey RCA,
What does she weigh with the 180?

Good luck on your maiden flight - let all know how it goes!

Jim

I don't know. My scale only goes to 5 pounds.

Thanks, I hope to have her out this weekend.

I balance dry. I want to be sure of the CG in a worst case landing. For example, a bone dry deadstick, I want to know I'm not too tail heavy to flair safely.

With the forward CG you will have to fly with power into the flair. If you come in just at idle, it may not flair at all. Especially if you land before you burn out most of that 20 ounces.

Fly down to a foot or so at or near idle. Pull back to flair. If the nose does not come up, then add a click or two more power. Control your descent with throttle and speed with the elevators. A biplane has a lot of drag to overcome, and with the forward CG may want to land hot.

If you deadstick, point the plane down several degrees, and come in with as much speed as you can maintain. Land deadsticks as hot as possible until you have done a few. Biplanes lose airspeed fast!

Thanks for the info!

I almost did a real bad thing.

I balanced the place with a GP CG machine. It showed CG to be on with the battery right behind the bottom wing. I flipped it over and used the finger method on 2 3/8 dry and it was WAY nose heavy. I had to move the battery pack to behind the cockpit. I made a battery tray out of some lite ply and some balsa scrap. I then CA'd some CF veil around it to give it strength to handle abuse.

I have to engineer a battery clasp for the tray, get a pilot and button it all up. Should be ready for this weekend!

I can't wait!

DOAH!!!!

Got to the field. Hmm, still soggy. Oh well other people are flying might as well give it a whirl.

Start it up. Gawd I love the sound of a four stroke at idle.

Warm it up. Check everything one last time.

Unhook the tail from the safety rope and start to taxi.

Gun it a little and NOSE OVER

Broke the prop. Didn't have another that would fit in the spinner.

So freekin rookie.

Anyway the mud collected on the wheels and then filled the wheel pants. As soon as that happened it nosed over.

Hind site, none of the people flying had enclosed wheels.

Bummer, bummer, bummer.

Decided to not worry 'bout it and pulled out the heli and flew a couple of circuits and then decided I could not see it well enough. It had been overcast all day. I got the x-spec down in one piece and called it a day.

As soon as I had my truck packed up the rain started again.

I am never going to get this thing off the ground!

Sorry bub, my maiden voyage was flawless. My throws were:
Elev. 3/4
Ailr. 1/2
Rud. 2

With my current c.g. right at the center of the range, I felt I needed more elevator. I now have it set at 1 inch. Eventually, I think my c.g. will be at the aft most position or slightly behind. I like clean snaps and no pull-out on vertical down lines.

The Saito 120 was amazing. I can't imagine what a 180 would be like (visions of failed wings). The 120 is one sweet engine. Very easy to tune and run (10% CoolPower, stock plug, APC 15-7).

I think for 90% of aerobatic flying, the Saito 100 would be a better choice. It's just so much lighter. Handling in every flight mode except straight up would be better. If you hot-dog and 3D a lot, you'll want the 120.

I don't see a wing failure, but tail flutter is a real threat. Just keep the prop pitch low and use some real discretion with the throttle. With my Webra 120 and a 16x6 I flew at full power in level flight. I did not suffer any flutter, but even 1 degree of a down line I was coming back to almost idle.

Hmmm, A Saito 180 and an 18x6 Bambula would be a blast!

ilikeplanes:

Cool! Thanks for the real world settings.

Congrats on a flawless maiden.

My CG is right in the middle range. My big issues was the axial balance. I had to add 1 3/4 oz of lead to compensate for the engine being side mounted.



TailTwister:
I will definately be on the lookout for flutter.


Thanks all for the input.

RCA,
When do you plan to put your Blue Hawk in the air, I'm anxious to hear how it goes.

Good luck,
Jim

One of those weather permitting things.

It was perfect out today. A little chilly but no real wind. Looked great from the window of the office.

Boy do I want to get this thing in the air!

I can normally get away with flying my heli at lunch but the setup and tear down time of the bipe puts me over the time limit.

Plus if I dumb thumb it, it makes for a bad afternoon.

Forecast doesn't look that good either:

http://www.weather.com/weather/local...ocalUndeclared

Don't rush it. I only do a maiden flight if everything is right in my world. Airplane, weather, nerves, etc.

I did the lateral balance tonight. It took 1.5 oz on the left wing (ouch). I guess the combination of big cylinder hanging out and a short wing span results in a lot of tip weight. I could have done an inverted mount and on board glow for the same weight.

My Ultimate came in at 8.75 lb ready to fly. That includes Saito 120, 1.5 oz lateral tip weight, Stan's Fibertech cowl and pants, five servos, standard receiver and battery, beefed up strut mounts, triple wing saddle structure, and NO tail weight.

BTW, mine is built from a raw kit (old style).

I'll post a pic as soon as the weather warms so I can finish painting.

Well she flew .... and she had her first crash. All in the same flight.

I checked everything 5 times started her up and she flew great. I was doing tail slides spins you name it.

Then I here this beeping noise. HMMM. I don't think I have been up the 8 minutes I set the timer for. Yep it was the TX battery warning.

I tried to compose myself but it was too late. I tried to force her down and she did just what I said. In my haste to get down i had forgot to turn off high rates and ended up giving her more down than I had anticipated on final.

She prompty slammed the wheels down then flipped over.

I was going slow enough that it looks like I just broke the prop.

So now I am 0 for 2 on props. I am so glad that is all that I am having the replace mind you.

DOOHH. That is two rookie mistakes! Shame on me!

The big deal to me was there was a record turn out at the field ......... I hate doing stupid stuff in front of other people.

RCA,
Any new report on your Ultimate - have you had it up again since the maiden flight?

I have had a great time with the plane. The engine is what I am not happy with.

I have had 5 out of 7 deadstick landings. I am chasing fuel gremlins now.

When the engine is running, oooohhhhmmyyyygggaaaawwwddd.

All I can say is yeehaa!

I am running a 16x10 APC prop and it is a great fit for the engine. It will pull verticle at 1/2 stick. Anything bigger will walk on the ground. I can idle the 16' prop without rollout.

My last dead stick was not so gracefull. I cracked both interplane struts, cracked the lower wing D tube and broke my custom battery mount.

No biggie to fix just wish I could figure out the engine stall problem.

I moved the tank farther back to help ground handling. I am going to get a header tank the next time I am at the hobby shop and mount it at carb level in the cowl. I hope this will fix my engine stopping problem.

One last thing.....this plane is fast for a bipe. I LIKE IT!!!!!!!

They don't call it Ultimate fot nothing! Did you knife edge loop it yey?