Help, I misplaced my instructions and don't know where the CG is. Could someone please tell me?

To Quote silverserfer...

"For those about to, or currently setting set up an Ultimate, an addendum to the C/G notes in the instructions should be added not to exceed 6-7/8" aft of the leading edge of the top wing measured from the "point". Anything aft of that point will be exceeding the maximum aft C/G limit for the plane, and can leave you with a plane dangerously quick and loose on the controls.

An excellent location for superb performance will be in the 6-1/2" to 6-3/4" range.

Pat"

6-3/4" would be the best all around location. Aft of that by any amount and things start to change on you. Aft of 7-3/8" and full loss of control will always be imminent. Behind 7" at all the plane will not be predictable.

I tried to cover all the bases with the numbers. As always, any plane can be set up any way an owner wants it, but the 6-3/4" mark will provide smooth landings at the slowest possible speed and provide excellent 3D flight. The same C/G can be used for IMAC flying by simply reducing the control travels.

Pat

Thanks guys. I generally don't fly more for port than anything so I really want to start at a more docile CG to start with. Sounds like I should start at 6 1/2 behind the leading edge of the top wing and adjust from there.

How do you guys like yours? Any bad habbits that I should be aware of before maiden? This is my first ultimate.

I put 20 some odd hours on one last year. I hade very little trouble with it other than some glue issues that have been posted in these pages someplace by others. short Recap Glue extra braces behind the fire wall mine came loose after much abuse. add a 1/4 inch square stock brace on the lower wing supports where the forward former is the ply has let loose on some peoples planes. Some people added better wood tabs where the supports attached to the upper and lower wings. I did not and after a crash every one of the tabs stayed in place even when the lower wing was fractured I can see how you might break one off moving the wings around unattached. lastly on the glue thing check the servo mounts I think every plane out there has had some kind of mount failure I for one lost a elevator mount. But that could be the abuse it gets going from my tinny little basement shop to the car. Tom's Plabes take a huge amount of use and abuse from me and he takes good care of me when I mess up. Thanks again Tom for all your help this years ultimate will be flown harder than It has a right to.

As far as bad habits nothing out of the ordinary It will not fly without a motor so if you have engine troubles stay high and over the runway if you can. she wont build speed in the downline so finding the runnway when the fire is out is a must. If you set the top wing at +1° I think it is. Or for guys like me with little cash for fancy tools 1/16 up or less on the leading edge The stalls will become very managable. I would try a few stalls at higher altitude so you have a good feel before you make your approch. I found that a click or 2 on the throttle off idle and she would settle in to a nice nose high landing.

here is a video of my first or 2nd day out now keep in mind this is my first biplane of any type and my first year with gass powered planes.

http://www.rivervalleyflyers.com/Vid/ some other Videos I have on our club site
[link=http://www.rivervalleyflyers.com/Vid/landings3.wmv]small 4meg vid[/link]

[link=http://www.rivervalleyflyers.com/Vid/ultimatelandings.wmv]Larger 20 meg vid[/link]

I hope this helps I know I loved this plane so much im building another one. last one had a experation date I was unawair of.

The only bad habits the Ultimate will have would be induced by using excessive control travel. The plane is extremely responsive, and quick. If you use what's been pretty much the standard 3D travels used on most mono planes it will be too much. More than 30 degrees or so of rudder is excessive, as is any aileron travels over 28 degrees. 40 degrees of elevator wil take you anywhere you may want to go.

Plan your landing approaches as you would just about any bipe by allowing for a little steeper angle of descent the first time or two. Most bipes don't "float" down a runway like a mono plane, but after your first couple of landings you'll find that this Ultimate will land slower than you might have thought. Just don't try to slow it down to a crawl 5 feet up over the runway.

Good luck and enjoy,
Pat

Doubled, sorry

Thanks for all of your help guys. I set the CG at 6.5" behind LE of the top wing at the wing center. I hope that will be enough because I had to put both receiver batteries in the tail and rudder servo also in the tail. I should be ready for maiden tomorrow, if winds are not to bad. We had 20 mph cross winds today at the field.

This Ultimate is one sweet plane. The more I fly it the more I think its the best for 3D. Control throws on the ailerons or the only thing you really want to be careful about. I setup triple rates to make rolling harriers and circles much easier. On high rates I have setup it simply will roll lightspeed fast. I have very high rates for the elevator but I think it works well for harriers and elevators. Ultimates will settle into harriers and elevators with extreme ease.

My CG is slightly aft and even more so now with the Brison 3.2 up front. I will have to adjust fire IF and WHEN my BME 55 finaly gets here. I think another awesome engine choice besides the 3W twin would be the YW twin. The singles are fun but much more goosing of the throttle in a hover.

I have had no issues but followed instructions on checking and gluing certain areas. Landings have never been an issue. I will say the dead stick landing approach for an Ultimate is to point the nose at the ground and flair at the last minute.

If Wild Hare were to release a 33% or larger I would snap it up in a minute. I really enjoy no flying wires and the rigid interplate struts.

Thanks Airborne, I am using a MVVS 58 powerhouse. I have 2 of these my other is on a WH Edge and will hover at 1/4 throttle and pull up out of sight like a rocket at 3/4. The only problem with this plane is if I need to CG past 6 1/2", I will have to add dead tail weight because I've moved everything to the tail already. Where did you start your CG for maiden and did you move it later?

I will be retiring the Edge and using that 58 for a 33% TOC Yak that I plan to buy at Joe Nall.

I am also going to put a EVO 58 in my 2nd Ultimate I am curious about how you setup your rudder and where you placed your batteries. Im considering making a single servo mount under the plane as Tom pointed out in this thread:
http://www.rcuniverse.com/forum/m_40...tm.htm#4076133

I used a single 5955 for the rudder push-pull and I had to place both batteries at the tail under the hor. stab. I used velcro and foam to hold it in place. I thought about making a tray under the fuse at the rear to pull-pull but the fuse is to wide. I had to put weight at the rear with this motor.


Maiden flight today. This plane does have alot of drag compared to a mono wing plane. You do need to fly this bird in. I tried to check the stall from a safe height and was unsuccessful. Full elevator and she came straight down in a harrier, straight down, no wing rock at all. I have been very concerned during the build on this plane and found a few things that I don't like about this plane but I think once I get used to the characteristics of an Ultimate, I will like it. The only problem that I had with the plane is the cowl came loose during flight because I didn't want to use the ugly rubber washers. There going on tonight.