In some kits, the main air frame body tube is in two sections joined by a coupler.
The tube joint might be at a color separation point like on the Estes Cosmic Explorer. TIP: If the separation joint falls on a color separation, don't glue the tubes together during initial construction. Glue them together after spraying. and you'll have an easy color separation.
But on models like the Monarch, it seems the tubes are in two pieces only for shipping purposes. Estes could fit the tubes into a smaller bag and more kits into a shipping box. This is just a guess on my part.
This leaves the builder with the job of filling the tube end joints.
Some minimum diameter Centuri kits came with two part body tubes. This illustration is from the Centuri Scram Jet. In those kits the shorter tube was to the rear, the coupler served as the engine block. This saved first time builders from problems setting an engine block 2 1/2" from the end of the shorter tube.
The Patriot comes with a 3-piece body tube: 2 white, 1 yellow. When I built mine I tossed the three tubes and two couplers into my stash and substituted a single piece of BT-60.
ReplyDeleteHi Rich,
DeleteThe Patriot was in three sections! I could understand two sections, the upper section was colored yellow, a pale yellow.
It is easier to use a longer tube instead of filling the seams. On mine, I made the yellow tube a payload section.
If I remember correctly, there were some Centuri kits where bulkhead discs with some holes were glued the ends of the coupler to form an ejection baffle.
ReplyDeleteHi Naoto,
DeleteYou are right. The Centuri Centurion body tube sections were joined by a baffle/coupler.
I didn't even think of holding off on gluing the tubes together until painting. I'm working on my third Cosmic Explorer right now - after losing my previous E motor build - and already glued the tubes together. I wish I'd thought of that!
ReplyDeleteIt's OK, though. I've got more. Those holiday sales were ridiculous!
Hi Rocket N00b,
DeleteThe old Centurion instructions (the model the Cosmic Explorer is based on) say you can delay gluing the two tube sections together after painting the lower half white and the upper section black. An automatic mask!
The Centurion instructions can be found on Jim Zs.