To shorten them properly you need a lathe

I'm talking about shortening 18mm motors to "Shorty" length. I'm not implying you can turn an 18mm motor down to a 13mm motor with a hacksaw!

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Scott D. Hansen
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WOOSH NAR Section #558

Just don't tell the RSO you have an A8-5S in your Sprite!

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Paul
If we weren't all crazy, we would go insane - Jimmy Buffett
NAR #87246 www.wooshrocketry.org

Yes--and the Estes 13 mm adapter mount (the 1970s-vintage one) had a failure mode that wrecked my Sprite clone. It was tumbling back nicely when a gust of wind slowed its tumble momentarily. When the rocket's nose next pointed down, the 13 mm motor mount with its spent mini motor slid back down (forward) into its boost position, and the now-aerodynamically stable Sprite fell nose-first to its destruction. If anyone uses this method to fly the Sprite on mini motors, the centering rings of the adapter mount need to fit inside the rocket *just* tightly enough to prevent it from sliding back inside; a bead of glue or a few wrapped strips of masking tape on each centering ring would be sufficient.

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Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see:
http://www.lulu.com/content/paperba...an-form/8075185
http://www.lulu.com/product/cd/what...of-2%29/6122050
http://www.lulu.com/product/cd/what...of-2%29/6126511
All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com.
NAR #54895 SR

Well duh, I know silly. I meant if you want nice square ends to meet up with the engine block, lopping them off in the lathe works best. I did use the word "shorten" but I guess you missed that part.

But now that you mention the 18mm to 13mm idea, hmm...

Farriers used to do that to Shires and other cart horses in 19th-Century England; instead of heating and hammering a "stock" horseshoe to fit a hoof, they would rasp (file down) the *outside* of a hoof to fit a horseshoe! How would them two-leggers have liked it if shoe vendors had done that to *them*? Also:This could even be done in quantity. A 2 X 4 board could have a row of 18 mm holes of the proper depth drilled into it, and 1/2A6-2 motors would be inserted into the holes, nozzle-ends first. Then run the board past a bandsaw or (maybe) a table saw, and--as talk host Jim Bohannon would say--"VIOLA!" Instant Series III 1/2A6-2S "Shorty" motors!

__________________
Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see:
http://www.lulu.com/content/paperba...an-form/8075185
http://www.lulu.com/product/cd/what...of-2%29/6122050
http://www.lulu.com/product/cd/what...of-2%29/6126511
All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com.
NAR #54895 SR