Excellent thread! I didn't know you could do that to heli blades.
ya. handle/hook. i originally had the MKII powercore on it. it provided a good way to hang the starter on the side of my pitbox. but when i upgraded to a lipo the battery wouldnt fit in the powercore. so i lost it and put on a piece of vblade to hang it by.
I was advised not to pair them together as they were dynamically balanced or it's not a matched set per se.
good advice, unless you know how to balance them. check out switch26's old post
This reminded me of one morning at work, had a jet come in with moderate vibration in the airframe from the #1 eng, the history was they did a fan lube job the night before at a hub. The vibration was small until you spooled it up to high N1 speed. This was on a RR AE3007.
The night shift took a few blades out and they forgot to mark them where they came from.
They installed them in the way they thought it came from...the next morning my shift comes in and we fired up the engine...the next thing we know after the engine got to ground idle speed, there was a ring of fire around the fan blades in a circle of rotation!
Shutdown...take the blades out and balance each blade (each blade has their own weight down to .02 grams) and found 2 blades that wasn't the correct weight in the set...in a few hours a box of 2 new balanced blades came in and we installed them...fired it up again and it ran smooth. Then we had the plane ferried down back to the same hub and they had to replace the fan casing...lol