Merrell

can anyone help me with the cg on the lanier cap. I bought this plane from a friend that had problems with the cg. It has a Brison 50cc on it, and it comes in at 22 pounds way to much. He hap to add about 2 pounds or so to the nose of the plane. can some one tell me what might be the problem?

BobPhx

We have a small bit of experience with this plane. You didn't mention what the factory specs are for CG vs. where your's CGs, and I don't know off the top of my head. However, make sure the perceived CG problem isn't really a thrust angle problem. The Lanier Cap that Hoss had would balloon like crazy when he pulled the power back, usually an indication of too much down thrust. Just a thought, perhaps the weight was added in an attempt to correct this. More details here:
http://www.goflyrc.com/projects/LanierCap/Laniercap.htm

Good luck!
Bob

Vacaman

Hi, what servos are you using? i am finishing the construction of the kit version, and i am wondering if a single hitec 5945 would be able to the job with both elevators halfs. It has a DA 50, and the estimated final weight is between 13 and 14 lb.(I use a lot of dremel and carbon fiber)

Albatross

My Feedback: (7)

I built this airplane, certainly is heavy even the kit. I am attaching some photos, one shows the CG range directly form the plans, the CG range is 9/16 wide. The blue prints call for zero (down/up) trust on the engine. Left trust is up to you. Before building this pane, I learned that this is a very heavy tail airplane. This is I invested in different materials from the original kit, among them I used contest balsa (see attached photo). By using this method I had the luxury to increase the surface of the ruder and elevator surfaces. Of course I used CF wing tube and CF LG. I did not have to add any weight on the nose.
By the way, I have noticed this ballooning effect, moderate an sometimes unpredictable; however nothing out of the ordinary, some down elevator during landig (if that ever hapens) has been enaugh to land the airplane whitout no problem.
22 lps is way too heavy, mine is 17 lbs (probably near 18 lbs my scale is very inaccurate)

I hope that helps.

Steve

My Feedback: (54)

For best landing you want the CG on the leading edge of the wing tube. Ballance it upsidedown.

Steve

Albatross

My Feedback: (7)

I might try that, as a mater of fact that's the way I used to balance my 60's and 120's airplanes, bit smaller and easy to handle in the shop when balancing. Nevertheless I think that a CG set to the leading edge would turn the plane nose heavy (as per the blue prints). I built this airplane specifically for 3D, I did not mind adding weight to the tail to move the CG AFT. If the price to pay for this modificatio is ballooning during landing, I don't mind to pay it as far as I can practice 3D. If I want to practice pattern flying, then I can remove the weight that add to the tail, I think it depends on what you want from the airplane. If I am not mistaking the "pros" use this method when the routine that tey are going to perform is a "free style routine" which calls for stalled maneuvers, before taking off they add weight to the tail. For pattern flying they remove the weight.

CK1

My Feedback: (60)

I built one a few years ago and put the Brison 3.2 in it , came out at 17.5 lbs and it balanced on the recomended C.G (although i don't remember what that was).
The plane few flawlessly at 17.5 lbs . However at 22 lbs i suspect it would not perform at its peak , esp. 3D
The Brison 3.2 was a perfect match. unlimited verticle .
I will say that at the rec. C.G this plane is very sensitive until you aclimate to it
And yes I would balance this plane upside down.
I built as per the plans and added no add'l weight to balance , I just placed my batteries carefuly

Merrell

Thanks for all the help guys. And the book calls for the cg to be 1" in front of the spar tub, although I'm not sure if that is from the center of the tub or the leading edge. I do know that with the cg at that point the plane was bad tail heavy,or so he told me...I can deal with the plane at 19 pounds, but 22 is to much!!!!! As for the servos I'v got 70oz on the wing halfs and 105oz on the rudder and elavator.. 2 on the elavator, and 2 on the rudder. All located in the tail of the plane...

Albatross

My Feedback: (7)

Merell
One of the pictures that I posted shows the actual blue print section with the recommended CG. The CG range( this range does not go beyond the wing tube) directly measured from the blue prints is 9/16 wide. I used a pull pull system for the ruder, this saved weight on the tail. I'll try to post other picture later showing the rest of the wing tube.

Merrell

Albatross,
Thanks for the info, and picture. As soon as I get this thing going I'll let you know how it went!!

Albatross

My Feedback: (7)

For you and anyone else interested on this airplane, I edited the picture anyway, including some quotations.

Steve

My Feedback: (54)

Lanier ammended the CG to go as far as one inch in front of the tube. Buba will give you all the info you need if you call him at Lanier.

Steve