Ace Mongrel

Dimensional data from original parts and a complete rocket circa 1980-1982

There was a lot of variation between each fin on the Mongrel - each fin was slightly different. This was a real mutt of a rocket. These are averages. The root chord and leading edge sweepback were pretty consistent from fin to fin.

Root chord - 8-1/2"
Tip chord - 3-1/4"
Semi-span forward - 4-1/4"
Semi-span aft - 4-7/16"
Leading edge sweep back - 7-3/8"
Trailing edge sweep back - 2.125"

The variation in the fin span wasn't pronounced. One can make the root and tip chords parallel, and still call it a Mongrel. The trailing edge of the fins met the airframe 1/2" above the aft end of the airframe.

Likewise the all balsa nose cones were different. Chris' Mongrel nose cone was a 17-3/4" long ogive (exposed length) while Curt's model was a 16-5/16" secant ogive. Truly a mongrel rocket.

Airframe - 34" long by 3.97" diameter (called, BT-39, back in the day. Close to BT-101) The airframe was slotted by the builder, and the fin tabs extended to the outboard motors - not the central motor. Thus the fin tab height wasn't very much - maybe a bit over 1/8".

Motor mount - 5x29mm with two centering rings at fin tabs. Motor mount tubing was 12" long.

two half-inch launch lugs, 3-1/4" long

36" military surplus silk parachute

Attached Files

Ace Mongrel original 1980.ork (1.9 KB, 16 views)

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-Wolfram v. Kiparski
NAR 28643 - TRA 15520
MTMA Section #606 President