Help! What to use for setting CG?

[WillL84]

So I've got my Legacy V2 done and it's pretty tail heavy even with the battery an the way in the nose. What do you guys use for weight? TIA

 

[CappyAmeric]

So I've got my Legacy V2 done and it's pretty tail heavy even with the battery an the way in the nose. What do you guys use for weight? TIA

I rarely add weight, but if battery position does not fix it, you can use lead fishing weights.

 

[Merv]

...you can use lead fishing weights.

Or used weights from a tire shop, they are free. Anything of weight will work.

Also could try a larger battery.

On some planes I’ve made the nose longer.

 

[CappyAmeric]

Or used weights from a tire shop, they are free. Anything of weight will work.

Also could try a larger battery.

On some planes I’ve made the nose longer.

I made a longer nose on the Arrow, Bushwhacker, Versa Wing, and Twin Bee just achieve an acceptable CG. I added weight to the nose of my Flerken, but when I build my next Flerken I am going to lengthen the nose.

Coming from full-sized aviation, it rubs me wrong to add unproductive weight to the nose just to balance. In full-sized aviation, we consider that inefficient.

 

[Monte.C]

I made a longer nose on the Arrow, Bushwhacker, Versa Wing, and Twin Bee just achieve an acceptable CG. I added weight to the nose of my Flerken, but when I build my next Flerken I am going to lengthen the nose.

Coming from full-sized aviation, it rubs me wrong to add unproductive weight to the nose just to balance. In full-sized aviation, we consider that inefficient.

+1

 

[ColoFlyer]

I made a longer nose on the Arrow, Bushwhacker, Versa Wing, and Twin Bee just achieve an acceptable CG.

+2
i also add a longer nose to help with balance. I added length to my Bushwacker, Simple Stick, Duster, Goblin, and Explorer. Depends on the plane, but usually an extra inch or 2 fixes the CG problem and allows the battery to move forward.
I just cut off the nose then cut out a new one with the added length I want, then use a couple of small skewers pushed in and glued into each side for strength.

 

[Merv]

...it rubs me wrong to add unproductive weight to the nose just to balance....

Agreed, I should be more specific, I never add unproductive nose weight.
On my Versa, a pusher, I move the motor forward to achieve the CG. This allows me to have the battery in the plane, not way forward where it will be damaged in a crash.

 

[Flightspeed]

Adding nose weight sux. In one of my gassers I have about a pound lol. Too much work to lengthen nose tho.

 

[Monte.C]

+2
i also add a longer nose to help with balance. I added length to my Bushwacker, Simple Stick, Duster, Goblin, and Explorer. Depends on the plane, but usually an extra inch or 2 fixes the CG problem and allows the battery to move forward.
I just cut off the nose then cut out a new one with the added length I want, then use a couple of small skewers pushed in and glued into each side for strength.

How good a design is it, really, when we have to make so many basic design modifications just to get it to fly?
Or are we just using batteries far different than what was originally used? The last thing I would want to do is add unnecessary weight.

 

[ColoFlyer]

How good a design is it, really, when we have to make so many basic design modifications just to get it to fly?
Or are we just using batteries far different than what was originally used? The last thing I would want to do is add unnecessary weight.

I think you are probably correct that there is a alot of very different batteries that change the CG. Also some of us to alot of modifications to the planes so that it is not even close to the original design, like Landing Gear, Motors, ESCs, Paint, Decals, changing the Servo Positions and such. These modifications along with how much glue we use and where can also mess with the balance.

 

[rcbigtirepilot]

I made a longer nose on the Arrow, Bushwhacker, Versa Wing, and Twin Bee just achieve an acceptable CG. I added weight to the nose of my Flerken, but when I build my next Flerken I am going to lengthen the nose.

Coming from full-sized aviation, it rubs me wrong to add unproductive weight to the nose just to balance. In full-sized aviation, we consider that inefficient.

because it is inefficient, even in RC

 

[WillL84]

Well I'm using the recommended battery for the Legacy V2 and with it all the way to the tip of the nose it's still tail heavy. I'm going to pick up some stick-on wheel weights and use those

 

[Monte.C]

Well I'm using the recommended battery for the Legacy V2 and with it all the way to the tip of the nose it's still tail heavy. I'm going to pick up some stick-on wheel weights and use those

See, something's messed up here. As far as you can see you're doing the same as what they did and what they say to do, but theirs balanced as far as we're told.

Maybe we're being lied to. Maybe they're the hardcore Leftists hell bent on destroying democracy...

 

[WillL84]

See, something's messed up here. As far as you can see you're doing the same as what they did and what they say to do, but theirs balanced as far as we're told.

Maybe we're being lied to. Maybe they're the hardcore Leftists hell bent on destroying democracy...

I've got no idea lol. Maybe I used too much hot glue for the tail unit? Also the V2 has the two extra vertical stabilizers on the rear horizontal stabilizer but that shouldn't add much I wouldn't think.

 

[Monte.C]

I've got no idea lol. Maybe I used too much hot glue for the tail unit? Also the V2 has the two extra vertical stabilizers on the rear horizontal stabilizer but that shouldn't add much I wouldn't think.

Yeah it's weird. I was gonna joke that maybe you used a bucket-load of glue, but I don't want to hurt any feelings. Maybe just a little more foam and a little more glue is all it takes. (?) I try to give my designs miles of battery space because I have no idea where it'll want to be. I haven't had much hands on experience with FT designs, but I get the impression there's not a lot of play in battery placement in some of them.

But I think it's the socialists trying to mess us up.

 

[WillL84]

Yeah it's weird. I was gonna joke that maybe you used a bucket-load of glue, but I don't want to hurt any feelings. Maybe just a little more foam and a little more glue is all it takes. (?) I try to give my designs miles of battery space because I have no idea where it'll want to be. I haven't had much hands on experience with FT designs, but I get the impression there's not a lot of play in battery placement in some of them.

But I think it's the socialists trying to mess us up.

The Legacy has a good amount of room in the nose for the battery if you're using a twin-motor setup. If you're using a single then the motor and ESC mount to a tray that goes in the nose.

 

[SEEBO]

I realize this is an old thread but was there ever a consensus on the best way to balance a twin engine Legacy? I have two 4s 2200 batteries all the way forward in the nose and get a good balance but I cant actually mount them in there due to lack of space. The two batteries together weigh a little over 19oz so I'm thinking I can make a Zeee 4s 6000mah battery work well as its an appropriate dimension and 22oz so I'll be able to mount it just slightly rearward to allow some crumple zone in the nose to protect the battery in a worst case scenario. Any thoughts on that theory? I feel as though a twin engine Legacy has plenty of power/lift to get that brick of a battery airborne.

 

[WillL84]

I

I realize this is an old thread but was there ever a consensus on the best way to balance a twin engine Legacy? I have two 4s 2200 batteries all the way forward in the nose and get a good balance but I cant actually mount them in there due to lack of space. The two batteries together weigh a little over 19oz so I'm thinking I can make a Zeee 4s 6000mah battery work well as its an appropriate dimension and 22oz so I'll be able to mount it just slightly rearward to allow some crumple zone in the nose to protect the battery in a worst case scenario. Any thoughts on that theory? I feel as though a twin engine Legacy has plenty of power/lift to get that brick of a battery airborne.

I ended up having to put a ton of lead fishing weights in the nose of both of mine. I tried to use a lot less hot glue on the tail of the second one but it didn't help

 

[Piotrsko]

Couple of well sized and located holes back by the tail feathers helps, too. However, in the case of my Olympic glider, the build instructions make you add their mandatory 16 oz of nose weight. Even have a how to set of instructions.

 

[SEEBO]

Took a chance and it paid off! Perfect CG, Perfect fit and hopefully a very long run time. Hated the idea of shoving one of my sturgeon rig weights in the nose.