jeffsos3000

my father and i are baffled we have a fancy c.g balancer and my father is trying to balance his great planes dazzler but its doing soething really funny that none of the other planes have ever done..it appears to be totally backwards when we add wait to the tail instead of the tail dropping the tail rises and when we add weight to the nose instead of the nose dropping the nose goes up and the tail goes down. it appears to be entirley backwards and we can not figure it out as to why. it appears to be defying physics and we are stuck cratching out heads at this we have tried balancing the plane both right side up and upside down and teh effect is the same and we are balancing on the recommended c.g point. if anyone could explain to us as to why this is doing what it is please inform us, as we can not figure it out

thank you!

MinnFlyer

My Feedback: (4)

Put the fancy balancer away and try using your fingers

R/C Skyjumper

I agree with Mike - Use your fingers at the CG point and dont forget to balance it nose to tail as may have a one wing heaver than the other
Don

jeffsos3000

hi don thanks for the reply but i am a little confused..when u are balancing for c.g is that not balancing the plane nose to tail? not quite sure what u mean by that. and as for the finger tip method we were doing that last ngiht and we still had the same effect. when we added wait to the tail the front end was dropping and the tail was actually lifting and vice versa should the tail not drop when u add weight to it? it does will all ourother planes except for this one!

jetmech05

Isn't the Dazzler a low wing airplane? Are you balancing it upside down.....If it's a low wing you should be upside down or (at least for me) you'll never get the balance right...kinda like pushing a string up hill...ain't gonna happen

FLAPHappy

My Feedback: (209)

What type or make of balancer is it? If you use the balancer correctly you should not get those results. Maybe you have the plane facing the wrong direction when on the balancer???

jeffsos3000

well the plane is actually more of a mid wing i would say, and we did try balancing both right side up and upside down and nothing seemed to make a difference

Lnewqban

Then, the CG is vertically inside the wing.

The only soluton I see is using a Vanessa rig:

http://www.rcuniverse.com/forum/m_70.../tm.htm#708060

jeffsos3000

its the great planes cg balancer. we have it set up properly as far as we know and its worked top notch with all our other planes we set it at the proper cg recomdations and line the leading edge of the wing up with the little metal arms flush with the edge of wing. we have balanced and alpha trainer, a twist 40, a tango, and a goldberg tiger 2. all have worked well just this dazzler is acting really weird and we cant figure out why. i mean we have it apparently sitting just slightly nose heavy right now becasue it was quite tail heavy so we started adding weight to the fron nose thnking the nose would come down but instead it kept getting more and more tail heavy so we started adding weight to the tail and the nose started to come down. its completly backwards.as far as we know we now have it sitting a bit nose heavy, but w cant figure out why it was balancing ass backwords! and im a little worried that things might not be what they seem and something bad is ognna happen on first flgiht,lol. and like i had said previously evn balancing on finger tips it was still reacting the same way as well as right side up and upside down

Scar

My Feedback: (3)

Well, it's obvious to me, you're putting the weights on upside down.

Great troll!
Dave Olson

RCKen

My Feedback: (9)

What are you using as the balance point for this plane??

According to the manual the plane should be balanced at a point 3" back from the leading edge of the wing. Turn the plane over, measure back three inches from the leading edge from the wing, place a mark there, turn the plane back over, and place it on the CG machine on the marks you made on the wing. Then balance accordingly.

Ken

jeffsos3000

yes we are balancing at 3 inches bang on as per instruction manual

jeffsos3000

and thank you lnewqban for the link to that "vanessa rig" my father and i are going to build on of those to see how it works just gonna bea bit ebfore we can build it, but i still havea feeling the plan is oging to be acting all backwards but we will see i guess, im still scratching my head. i mean we know how to balance planes weve done quite a few. just this one is doing something weve never seen before

RCKen

My Feedback: (9)

Is there any way you can take a picture of how you are trying to balance and post it here. Something just doesn't add up. The laws of physics don't change. If you add weight to the tail the tail can't go up, or vice versa. Something isn't right. A picture would go a long way to figure this out.

I have the Great Planes CG machine as well and it's a good tool for balancing planes with. I use it balance all of my planes and it does a good job.

Ken

Lnewqban

You are welcome.

Just make a little experiment to stop scratching your head:

1) Place a looping string under the wings (just like the Vanessa) and hang the model horizontally.
2) Place an arbitrary weight on the tail or the nose.
3) Watch the model swing away from the end on which you placed the weight.

If it happens that way, it means the model is dropping the end with the added weight, as it should be, and also that a properly built Vanessa rig will solve the mystery.

I believe that the problem you have is related to the natural instability of the situation where the CG is above the pivot point (skin of the wing in contact with the balancer).

As the schematic shows, the situation in which the CG hangs from a pivot (Vanessa), is self-stable.

Regards

jetmech05

I think LNEWQBAN is correct...no matter which way you put the model, upside down or right side up, the weight of the aircraft is above the point of the balance machine.....
I heard you say that you added weight to the nose then you added weight to the tail.....have you moved the battery and receiver around first?.......time to remove all the weights and start over with the Vanassa jig......good luck

JohnBuckner

My Feedback: (1)

Indeed takes all of perhaps thirty seconds to check the balance on a dazzler or any other non giant scale airplane that is difficult to use on conventional relitively friction free balancers because of the midwing designs and no clear cut best stabile position. There is no mystery here.

Use Your Fingers

John

MinnFlyer

My Feedback: (4)

What Don means is to also balance it laterally. Lift it at the nose and tail and see if it always falls to one side - that is, see if the same wing drops every time. If so, add weight to the other wingtip until it falls either way (You'll rarely get it to balance perfectly, but close is close enough)

geh3

My Feedback: (84)

For planes with removeable wings (most jets)Iuse just two cords suspended from my garage cieling through some turnbuckles, the ends protrude through a 1/8" wing gap
created by not fully pushing the wings fully against the fuselage! These are looped through a dowel that is positioned exactly at the desired CG. Then by pulling on the cords, Ican adjust the CG by adding weight or shifting batteries
inside the plane. This is a very quick and easy method and also very reliable

R/C Skyjumper

Thanks Mike for clearing that up - I dont get the right words sometimes but I get the how and why LOL