Batteries slipping down the blades?

[ryane67]

Hey I just built my first set of night blades.

Set up is on a trex 450 - so 325mm blades, running ~2850HS the batteries are 1s 160mah 30c, held in place by some 3m tape below, then 1" clear heat shrink around them (extending another 1/2 inch down the blade past the end of the battery)

I've noticed after a few flights that the batteries have started to slip down toward the end of the blades, I don't want one coming out mid-flight.. I've already had it happen once, on my first test flight, that was a fun landing!

They are about 1.25 inches from the bolt hole, do they need to be even closer than currently?Is there some secret ninja way to keep them stationary? maybe I'm using too large of a battery?

[kavic5150]

For that size blade I usually recommend 120mah. 160 should be fine. I mount my batteries as close as possible while staying on the flat surface before it curves into the blade root.

I had that same issue with the exterior 3m mounting tape. For some reason the indoor 3m foam tape works a bit better. You can also use some CA on either type of 3m tape.

Was the heat shrink tight after hitting it with a heat gun?

[ryane67]

Originally Posted by kavic5150

For that size blade I'd recommend 120mah. You could go 240 but it might mess with the way your heli handles.

I had that same issue with the highest holding strength 3m tape. For some reason the 3m foam tape with the 10 pounds per square inch rating works a bit better. You can also use some CA on either type of 3m tape.

What size shrink wrap did you use over the battery? Was it snug after hitting it with a heat gun?

Thanks for the response!

I used 1" heat shrink around the battery, resistor, and wires, it's definitely snug.. the battery has a pocket of sorts, the heat shrink is tighter further down the blade where I left some room.

I think I see why you're recommending the foam too. I just cut off the heat shrink and noticed the outdoor 3m double-sided stuff is more of a highly viscous goo, not a solid tape.

As for the handling of the heli, is it better to mount the battery on the leading edge, trailing edge, or somewhere in the middle?

edit: I'll order up a couple 120mah's should be half a gram or so lighter, can't hurt..

[kavic5150]

Mount the lipos closest to the chordwise CoG so I think just forward of center on most blades.

[thanasi]

Having the same problem my self twice. Second time I found the battery, using 150's.
I think trying the foam tape is a good idea Ty
Will form better to the curve of the battery and blade.
I even thought about using black electrical tape instead of white shrink tube.
Not sure if anyone has done that b4.

[Jason O'Connell]

I epoxy or shoo-goo a dam at the back of the battery so it CAN NOT slip down.

[TheBum]

On my 430mm night blades, I made sure the shrink tubing crossed the part of the blades where it tapers toward the root. That held the tubing in place and shrinking it to the contour of the battery kept the battery from slipping in the tubing.

[thanasi]

Yup that's what I ended up doing Bum !
Also over the battery a tad more sofar had been good.


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[aburkhardt]

I used the extreme 3M foam tape and have had good luck. Just make sure you clean it with alcohol to remove grease.


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