What's your Largest motor in LP tubing?

dmgrime said:

Flown the BT60 based star orbiter stock (wood glue only) on an economax G74-9W....only issue was transonic shredded the balsa fins. Tubes were fine. Rebuilt with basswood fins to fly again this spring on same motor.

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Sims projecting transonic speeds on a full G or low H is what has kept me from putting one in my Star Orbiter since the balsa fins, though TTW, are still only 1/8 inch thick balsa. No worries about the tube.

So far the most mine has seen is an F26-9.

Hmmm.....maybe I need to make one with basswood fins as you have. I have a couple more on hand and they're in stock at the local H-L. But then, what about the nose cone ?

Nose was fine... Flight was good, actually except for the fins shredding and all This is how it was recovered ... so I've carved out the balsa fins, filled the slots with rocketpoxy and cut new slots at 60 degree offset for 1/8 basswood fins. Looking forward to trying again

Walldiver7 said:

The tube's strength won't decrease,... but with a longer tube, other forces acting on the tube/airframe will be more prominent, which could lead to failure. The test I preformed was to determine it's compressional strength only.

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Ah, bad wording on my part. I was referring to the failure strength going down in buckling (Pcritical) instead of the pure material strength (tensile/compressive)