Battery position for cg

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10-09-2012, 11:25 PM
kphilliprc

Battery position for cg

So just wondering where everyone is putting their batteries to get the recommended cg. The position of the battery tray is too far back even with 4S 5000 packs in there, i cant get it to balance between 210 and 230mm. I had to remove the front wall of the battery tray and push my batteries forward till the back them is in the middle of the tray. I've gotten 63mph on my setup with the batteries in this position so i dont think they are too far forward. I feel like if I left them within the stock tray wall it would surely blow over at higher speeds.

Also, what size 4S packs are you guys using? Are you putting them in the sponsons and relocating the ESC's to the middle of the boat?

This is my setup:
Segad with two Leopard 2860 2730kv motors, Seaking 120's, .078" wire drive with 3/16" stubs (struts have been converted to 3/16") x442's and speedmaster dual pickup rudder cut off just below the bottom water pickup (my friend has a cnc machine so i had him cnc a new bracket to mount the new rudder)
10-09-2012, 11:48 PM
Make-a-Wake

You answered your own question................the boat wasnt intended "stock" to go 63..............you have really beefed it up with those stout leopards and at those speeds the intended location for the batts arent "right" to prevent blowovers.........you are on track with a 32+ % cog.
10-10-2012, 12:01 AM
Livewire121

Just wondering if you could post some pics?
10-10-2012, 12:15 AM
kphilliprc

Quote:

Originally Posted by Make-a-Wake

You answered your own question................the boat wasnt intended "stock" to go 63..............you have really beefed it up with those stout leopards and at those speeds the intended location for the batts arent "right" to prevent blowovers.........you are on track with a 32+ % cog.

Ok, that's what I thought. With the stock setup, it's just not fast enough to worry about a blowover.
10-10-2012, 12:29 AM
kphilliprc

3 Attachment(s)

Quote:

Originally Posted by Livewire121

Just wondering if you could post some pics?

Sure

These pics are with the 3S 5000 packs not the 4S ones but you get the idea.

Attachment 86125 Attachment 86126 Attachment 86127
10-10-2012, 12:53 AM
Make-a-Wake

I notice more and more folks goin with the hardcore waterlines............they look great but not sure they help cooling much.....................do they?? Don't get me wrong, I like bling too, I have just always used the neon yellow Tygon tubing cuz its cheap and readily available.
10-10-2012, 01:08 AM
kphilliprc

Quote:

Originally Posted by Make-a-Wake

I notice more and more folks goin with the hardcore waterlines............they look great but not sure they help cooling much.....................do they?? Don't get me wrong, I like bling too, I have just always used the neon yellow Tygon tubing cuz its cheap and readily available.

The black lines were left over from another boat i had. I chose those lines because the water pickups on the speedmaster rudder are pretty big. I wanted to take full advantage of that and not slow down the water flow as soon as it hit the hoses. The blue lines inside are larger inner diameter as well but the are just fuel tubing from my LHS. The slowest part of my cooling system right now is the water jacket inlet and exit. The seaking 120's have almost an eqaul size inlet as the rudder so the can take the extra water easily. I think it helps.
10-10-2012, 01:28 AM
Livewire121

Lookin sweet! My plan was to remove the tray all together. Who makes the rudder, is it a fightercat?
No need to reply about the rudder, i just read the last post:Peace_Sign:
10-10-2012, 01:44 AM
kphilliprc

Thanks!!

Yeah, I'm in the process of making a new battery tray for it now. Also trying to figure out the highest mah packs i can stuff under the middle of the hull. I think i can squeeze the 4S 35c 4500mah nano techs in there. Anyone have any recommednations?
10-16-2012, 11:52 PM
Skullcracken

Quote:

Originally Posted by kphilliprc

Thanks!!

Yeah, I'm in the process of making a new battery tray for it now. Also trying to figure out the highest mah packs i can stuff under the middle of the hull. I think i can squeeze the 4S 35c 4500mah nano techs in there. Anyone have any recommednations?

You could do 4s 4000's. Its more difficult to fit because of the width rather than the height. The Turnigy lipo's 8 gauge wires come out really wide off the side, adds another 8-10mm's to width. You may want to look at Zippy compacts.
10-17-2012, 12:19 AM
kphilliprc

My new battery tray will not have sides. It wil just have a couple places where I can use some Velcro straps to secure the batteries down and I'll have Velcro on the bottom of the tray as well so the will stay in place. Hopefully this will make my battery selection a little better.