So i have three short circuits and they are perfectly smooth. I got 4 upgrade kits and replaced the tip with the metal tip. All three have this crazy 
oscillation when throwing. It’s so wild it basically kills the spin and cancels any benefit to having a metal tip. It’s perfectly consistent, as in I’ve swapped them back and forth several times and the metal tip always makes the oscillation.
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Plastic tip swapped back on.
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Maybe it’s a known thing… but I wonder if an o-ring in the crown would balance it back out. A little extra rim weight might help with some added spin time??
No explication here, but Dave states in the video (and everyone who has the tip kit will verify as we learned it the hard way 
) the metal tips just throw the Short Circuit out of balance.
Ugh. Well I actually bought the kits to get spares, because the kit comes with all the plastic tips also. So it’s still helpful. But I didn’t do any research prior to purchase lol
Definitely a known and discussed issue. It’s a shame too. That thing would be sweet with the metal tip. The metal bearing tip is very nice on the Elec-Trik though. I also made a metal fixed tip Elec-trik. That is pretty darn nice. And made a plastic bearing tip Short Circuit, also very nice.
Ok i think I’m happy with the plastic tip and adding o-rings in the crown of the short circuit. The first high revving boomerang , the tip actually burnt my palm after a few seconds!!
I usually cut out the bottom inside of the crown and add 1 o-ring, but they work pretty well stock. That allows you to easily balance the top and gives some room to put your string in there, I always get rid of the giant YYF “button” and use something that will fit in the crown.
With the plastic tip, the axial moment of inertia of the Short Circuit is slightly larger than the transverse moment of inertia. When you put the heavier aluminum tip they become identical, so the top is equivalent to a ball, what makes it unstable (any small imperfection will drastically change the principal axis away from the geometric axis).
Interestingly, if you put an even heavier tip (steel), it becomes balanced again!
We discussed this here:
That’s some good reading. Thank you
