Loc 4 inch V2

[Scott Nokes]

Hello all

I have the loc 4 inch V2 and having some trouble with stability. I'm using open rocket, it's telling me that if I use the amount of nose weight according to the instructions which is 4.24 oz, it's unstable or very marginally stable with motor loaded. To get a one caliber stability it says I need 18oz. I saw another post on here we're 16oz was used. Please can I have some advice if I should add so much nose weight. I'm using the pre production for that's on the rocketry reviews website and the rocksim file loc has sent me.

Thank you

 

[sharkbait]

Hello all

I have the loc 4 inch V2 and having some trouble with stability. I'm using open rocket, it's telling me that if I use the amount of nose weight according to the instructions which is 4.24 oz, it's unstable or very marginally stable with motor loaded. To get a one caliber stability it says I need 18oz. I saw another post on here we're 16oz was used. Please can I have some advice if I should add so much nose weight. I'm using the pre production for that's on the rocketry reviews website and the rocksim file loc has sent me.

Thank you

Many moons ago, I did my Level 1 with a 4” Loc V-2, it had 6oz of #8 bird shot in the nose, it is retired now but was a regular flyer for many years

 

[DragonRocketry]

My 4" V2 has 10oz in the nose.

 

[Scott Nokes]

Many moons ago, I did my Level 1 with a 4” Loc V-2, it had 6oz of #8 bird shot in the nose, it is retired now but was a regular flyer for many years

Thank you

 

[Scott Nokes]

My 4" V2 has 10oz in the nose.

Thank you

 

[Scott Nokes]

The file loc sent me for rocksim but I use it in open rocket, they have 24 oz in the nose, is that incorrect then?

 

[Aeva]

The file loc sent me for rocksim but I use it in open rocket, they have 24 oz in the nose, is that incorrect then?

no it just means they added more weight for a higher stability margin. As long as the weight added doesn't bring the thrust to weight ratio below safe lift off velocity, you can add more. Depending on how draggy the rocket it is, it could add more momentum so it goes higher (assuming drag is the dominating force slowing it) or lower (assuming gravity is the dominating force slowing it). A V2 will tend to be more like the latter, so adding more will sacrifice altitude for stability.

 

[Titan II]

Please can I have some advice if I should add so much nose weight.

Up to now, you have mentioned 4.24, 6, 10, 18 and 24 ounces. You will have no idea what to add until you actually build the rocket and see where the CG is in relation to the CP. Adjust from there to achieve the stability margin you want, regardless of amount.

 

[bjphoenix]

I have the loc 4 inch V2 and having some trouble with stability. I'm using open rocket, it's telling me that if I use the amount of nose weight according to the instructions which is 4.24 oz, it's unstable or very marginally stable with motor loaded. To get a one caliber stability it says I need 18oz.

Is 1 caliber necessary for a rocket this short and stubby? My 2.6" V2 constructed from Estes Silver Comet parts has no nose weight and flies great on D12 motors.

I took some measurements of the 2.6" V2, I would think the aerodynamic parts of this would scale. You can compare with your sim and use your judgement. My 2.6" diameter V2 is about 22" long overall, the cylindrical part of the body is 7" long. With motor installed ready for launch it balances about 1" in front of the rear end of the cylindrical part of the body. If these measurements don't seem to scale up to your larger V2 I can make an OR sim based on my dimensions.

 

[MikeT]

I'm still adding weight to mine. I didn't measure but it was a bunch. It will fly next launch day the weather is right.

 

[MarkB.]

Guys,

With motor installed, any V-2 should be slightly nose-heavy at the scale joint between the fin can and the cylindrical body tube. For a scale V-2 from BT-50 to 4" diameter, it's the same spot. If you have a Silver Comet or a Canadian Arrow or a Project Blossom V-2 then you have some extra nose moment arm and can use slightly less weight but the balance point is the fin can/body tube joint.

And you won't know until you build it.

 

[David Schwantz]

My V 2 has 25 lbs of lead in the nose

 

[Aeva]

My V 2 has 25 lbs of lead in the nose

Holy crap… what are you flying it on?…

 

[David Schwantz]

M2050X

 

[David Schwantz]

It is 12" dia and 9' tall. Weighs 68 lbs.

 

[bjphoenix]

Guys,

With motor installed, any V-2 should be slightly nose-heavy at the scale joint between the fin can and the cylindrical body tube. For a scale V-2 from BT-50 to 4" diameter, it's the same spot. If you have a Silver Comet or a Canadian Arrow or a Project Blossom V-2 then you have some extra nose moment arm and can use slightly less weight but the balance point is the fin can/body tube joint.

And you won't know until you build it.

My V2 based on a Silver Comet balances 1" in front of that joint. It has been flown a lot and flies very well on D12-3.

 

[Donnager]

My V 2 has 25 lbs of lead in the nose

Not afraid of nose weight. You use it when you need it. And I use what I need, and don't fret about "why so much" if that comes up.

I have some Big Daddys that fly H's-J's. They may have more nose weight than body weight.