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ga1ba2
09-23-2009, 08:12 PM
My BMS clone of the month came with a foil lined motor tube. It also has an engine hook. Any special glue needed to attatch the thrust ring? Does the area need to be scratched so the glue sticks?

stefanj
09-23-2009, 11:29 PM
I've always assumed the lining needed scratching. I marked off the handle of my skinny X-Acto and scraped away the area.

I used yellow glue.

Bob Thomas
09-23-2009, 11:39 PM
I used some foaming gorilla glue forward of the thrust ring as a backup - it sticks to everything, use very little.

ga1ba2
09-25-2009, 05:19 PM
Thanks for the info. The tube is 9 inches and the rocket BT is 34 inches and I installed a baffle in the top about 8 inches from the NC. Do I really need all 9 inches of the motor mount or can I just cut it off a little longer the what I need for the engine and thrust ring. I intend on using a E engine or a D with a spacer

Bob Thomas
09-26-2009, 01:11 AM
The only reason I would think the foil tube is extended is to protect the main body tube just a little longer from the hot ejection gases and particles. Naturally, the longer tube also "aims" the ejection charge further up the tube (have you ever experienced a sidewall burn through just in front of the ejection charge? It is awful!)

If CG isnt a problem, the weight of the extra foil tube might only matter in competition.