One of the "L" pieces has a hole in it for the launch lug to slide through.
Apply a line of glue and slide the lug into place. Be sure that glue doesn't get into the lug.
Glue a 20/50 centering ring (not the split ring) even with the end of the BT-50 tube. A D engine will be friction fitted or simply tape wrapped for retension. There isn't enough room on the sides for an engine hook.
The top hole in the bulkhead is sized for the 18mm mount.
It'll have to be widened to the inside diameter of a 24mm engine.
Wrap some 220 grit around a 13mm engine casing and widen the hole diameter.
Set the BT-50 tube into the cage with the centering ring up against the bulkhead.
Check to be sure the hole is slightly wider than the middle of the centering ring.
To protect the inside hole sides wall from the ejection charge, rub some glue into the balsa.
Why no room for a hook? If aligned with one of the "points" of the interior pentagon, I would think there's plenty of room. Just needs to be room in there for a wrap of tape around it, and that would definitely not be a problem with mine.
ReplyDeleteThat said, I'm still not sure I want the hook, which would be annoying if I try something like an E9 but not a dealbreaker; just friction fit it in and let the hook stay pushed off on the side. I think.
Hi Neil,
DeleteI didn't add an engine hook for a 24mm engine. No real reason, I just thought it'd be easier to do a tape wrap around a D engine and engine mount tube. There would be enough room for a engine hook at one of the "points".
I don't know if I would use the longer E9 in this one, that engine would hang pretty far out the back end. I think a D will give it a better ride than the C6.
So if I have a 24mm motor mount from something else just sitting around, it should just be a matter of (carefully!) widening the hole and then gluing it in?
ReplyDeleteThanks for the writeup, I'm starting my build soon and this is incredibly helpful
Hi James,
DeleteI used the BT-50 24mm tube that came with the Quinstar kit. I make no guarantees that the 1/16" cage will take the strain of the D engine thrust. I only flew mine with a C6-3 so far. The "cage" is strong though, just be sure to fillet every joint!