PML Extended 54mm Kwik Switch Motor Options?

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talkin Monkey

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Jan 18, 2009
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Thinkin' about K motors for an L2 flight...

Really a cost planning and options question for those in the know. What motor cases Actually fit in a PML 54mm Extended Kwik Switch MMT?

It's about 17 3/8" long measured from the bottom of the forward threaded flange to the aft end of tube where a PML retainer will be. AND! I must mention, it's already built and installed, so the MMT just is what it is at this point.

(Yah, I know, If I really wanna go out and play with the Big Kids, I shouldn't limit my MMT's);)

On a tentative motor hunt, it *looks* like an RMS 54/1706 case might fit according to RockSim on a reload length (K550W) basis...but, then factor in Pro54/AMW/Loki type casing geometries/grain number and I start getting a little more dizzy than I usually am.

Any hard facts that I missed somewhere as to what cases one can stomp into said MMT and still get the retainer screwed in?

Thnx in advance for any input...

View attachment The Black Spark of Insanity.rkt
Last edited:


Well-Known Member
Jan 18, 2009
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These are the maximum size hardware for each manufacturer that will fit - according to your measurements

1) AMW and Gorilla 54-1400
2) CTI 54-4 Grain case
3) Loki 54-1600: unfortunately there are no loads certified for this case yet, so the 54-1200 case is your option with certified loads
4) AT 54-1706

Those kwik-switch mounts are the most useless and restrictive mounts made - and the forward screw is fairly fragile. Use standard 54mm tubing with Aeropack or homemade adapters for flying smaller diameter casings.