Entrada

Segurança

Oficina

Tecnologia

Projetos

Eventos

Endereços

TopBarRightCorner.GIF (1174 bytes)

Namor I em ascenção

Portal

Notes in English

My biggest problem is in finding parts. I've never seen an FTC (fluorescent tube cover) and PVC pipes only come in a few sizes. But I guess that makes it more fun always trying to come up with alternative solutions.

CURRENT CHALLENGE
After many frustrating attempts to build a crushing sleeve-type staging device, I had this thought of using the Clark Cable technique backwards (inwards?). Anyway. The idea is to have the cable ties grab the 2nd stage (the top bottle, the sustainer) from within, locked in place by a piston that gets pushed up by the pressure difference between the two bottles.

I´ve called this thing "Candiru" which is the name of a terrible tiny fish from the Amazon region. The indians are scared to death of this fish, much, much more than the "Piranhas". It senses the smell of urine and feces and it swims right towards their origin, making its way into the respective canal. Its scales are hard and sharp, making it easy to get in but impossible to come out. They are deadly!

My attempts at building this device is enormously hampered by my own incompetence in working with machines, tools, etc. To make matters worse, I haven't been able to find suitably-sized pipes to fit my original plan. Rats! I suppose one could use a lathe or something to get to the proper diameters.

If you guys could brainstorm about this idea I think it would be an interesting addition to our supply of rocket-related gadgetry. This is what I've accomplished so far:

candiru3.jpg (17465 bytes)This is a picture of a prototype. You can see the piston (in white) locking the bottle in place. At the bottom end you can see the PVC cap with a length of threaded lamp rod, which would be used to fix the assembly on top of the 1st stage (the bottom bottle, the booster), à la Robinson Coupling.

On top of the cap I've placed a section of 32mm PVC pipe to function as a ledge onto which the bottle rests. You must have a couple of these hoops in different lengths to accomodate the various tapering shapes of bottles.

The "piston" was made with the body of a ball-point pen.

candiru1.jpg (8981 bytes)These are the main parts:
(left to right) 3 different hoops of 32mm PVC pipe to use as ledges; ball-point pen modified to serve as piston; the "grabber" assembly - 4 cable ties squeezed and glued between the 25mm and 15 mm pipes; the PVC cap with the threaded lamp rod installed.

I like the way Paul Grosse draws his rocket plans. They inspired me to draw these:

Candiru-Projeto.GIF (6085 bytes)

At left, the piston is down, allowing the cable ties to come close to each other and freeing the bottle. At right, the piston is held up by a greater pressure from the booster, preventing the ties from moving and locking the sustainer in place.

The most important thing here is this: I HAVEN'T TESTED IT YET. So that you know.

 

 

Topo da página