Question

Hello

Does anybody have information on as to accomplish the alignment of the center of gravity in a rocket with a photographic camera? That is necessary? I build these small V2 and is worried with its stability when it uses a camera.

I thank the attention,

João Laudares

Joao,

First let me welcome you to TRF. This has been a great place for me and others to share and learn more about our beloved hobbie of building and flying rockets.
I notice you are from Brazil, glad to have someone from South America on board!
As far as your question goes, I can't help you directly. I will provide you however with a link to a great software program that im sure if you have not already tried. Will find very valuable. There is a free older version of their RockSim 4.0 you can download for free. Give this a try and it may help you with your stability issues on your great looking V-2. Nice job by the way!

https://www.apogeerockets.com/

Welcome again & good luck!

Cutt~

laudares,

Welcome to TRF!!

Did you say you are putting a camera in the rocket? I made a rocket that carries a disposable camera and it worked ok, but if you don't mind, could you share your ideas of mounting the camera. Nice rockets!! I love the V-2s. What motor are you going to use in them? Here is the link to my rocket:

https://www.rocketryforum.com/showthread.php?s=&threadid=2432

First off, I have to confess that I don't use simulation software like RocSim (I just fly low-power stuff) and I do not know how to tell you to prepare inputs for your design.
I can tell you that for any design, the safest way to design and build is to keep heavy component weights located on the centerline (or longitudinal axis). If a component of any significant size must be positioned off the centerline, you can use a matching mass on the opposite side to make things balance, but the combination still needs to be centered on the longitudinal axis. Small, relatively light-weight components could safely be located off the centerline (unless you locate a whole bunch of them on the same side).
If you are trying to get your camera to face toward the rear of the rocket (and take pictures of the ground as it launches), don't forget that you can keep the camera on the centerline and use a small mirror to look out the side and aft.
Once you get your basic design flying and can determine the initial stability characteristics, you will be able to make a better estimate of how much asymmetric mass your design can tolerate. If the thing flies rock-solid straight up, even in the wind, then you can probably begin trying small variations on your camera installation.

And in the picture I saw, that sure ain't no SMALL V-2!

Very nice model---how do you finish the sanding and shaping of
all that foam? Do you have some way to mount that thing
on a machine and turn it or do you sand by hand?

Hi,

Really, the V2's were not so small. I see them as small in front of the original, just.

The work with the foam was enormous. I used a mechanical lathe, that it was available in the weekends, in the university where I study. Initially I made a drawing in real size of the rocket and starting from him I obtained two patterns (one for nose cone and one for boat tail) to use during the machining, because the lathe that I used is not CNC. To set up the foam blocks, I glued several square's using epoxi, perforating each one initially. After the collage, I glued in the extremities two wood disks, that served as support for the lathe. The whole piece was crossed by a central tube to reduce the vibration during the machining. The same process was made so much for the boat tail as for the nose cone.

I am being a little calmer with relationship to the problem of CG, mainly because I can use a weight the same to the camera in the opposite position. Other components are also out arranged of the axis, but its mass is small.

I also love V2's. They are a magnificent vehicle, in particular if we consider the time in that they were done, with the quality of the materials of the time and without the electronics that we have today.

I took 20 days to build these rockets, once they were indent of a net of local television, so that they appeared in a soap opera scene. I had never made anything of similar size, just smaller rockets. It was a challenge.