will this work? making tubes

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rocketsonly

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Hey all, I already posted something similiar to this in this other thread about Saturn V.

They were trying to build a scale model of a Saturn V, but ran into some problems not having the exact body tubes needed.

Let me know if you all think this will work:
1. Get a bunch of centering rings cut (preferably from my TARC team :D) so that the OD is a tiny bit less than the actual ID of the tube you are trying to make. Also make sure the ID of the ring is the perfect size for a given wooden dowel to slide through.
2.Glue all the rings on to the dowel, maybe 3" apart.
3.Get some heavy duty paper, probably poster paper (not poster board). You can find it at Hobby Lobby.
4.glue around each ring and wrap the poster paper around the entire structure.
5.Buy some Mylar, and wrap it around the paper.
6.Buy some carbon fiber (EXPENSIVE!) or fiberglass sleeves from aerosleeves.com
7.Epoxy the sleeves on
8.Slide out structure when everything has cured.

Will this work? Is this already a widely known concept?
 

Ryan S.

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the way it is often done is, take a premade tube or mandral and wrap that then slide the CF off (need some kind of release) but your method may work if you keep everything nice and straight and make sure you dont stick to the rings
 

rocketsonly

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I mean this method would be used when making oddly sized tubes for scale rockets.
 

sandman

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That will work but...WORK is the key word there!

Here is an easier way.

1.) Get tubing that is larger than you need. (like for a 5.04" tube get a 5.2" tube).

2.) Carefully measure the wall thickness of the oversized tube. Now assuming the centering rings you can make are very accurate subtract the wall thicknes of the tube from the final tube size and make the centering ring THAT size.

3.) The dowel thing should work fine. Use that.

4.) Cut a nice straight cut the length of the tube.

5.) Fit the oversized tube onto the dowel centering ring "mandrel" and mark the overlap and cut that slice out of the tube so that it fits tightly onto the centering rings.

6.) Now glue the edges together and the tube should be the exact right size.

A lot less work than making your own tubes.

As for glassing or carbon fiber, that depends on what this thing will fly on. It does seem like a waste of money for a scale model.

With a scale model you want a slow majestic liftoff. Don't use an I600 motor!

That will look as scale-like as a Lionel train going around a 6" radius curve.

For the best scale type liftoff on a Saturn V you are going to want a cluster of 5 long burn motors, and a really long launch rail!

sandman
 

rstaff3

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I'm not an expert, but I think even an undetectable amount of error in uniformity will make the inner section impossible to remove. But I guess you could still use the classic technique of soaking the final assembly in water and let the poster board melt.
 

wwattles

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The method used in The Launch Pad Plan-Paks is to find the circumference and the length, then cut a rectangle of your material to that size. Also cut a second strip of your material that is about a half-inch wide and the same length as your desired tube. Glue half of the strip to the edge you are going to use as your seam - this gives you the overlap strip for holding the whole thing together. Then slowly roll the piece until it easily holds to the desired shape, then glue the overlap tab to the other side of the tube.

Kind of a pain, but it works for making any size tube you can possibly imagine.

WW
 
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