Battery size

[Max]

What size lipos are people running in beetles, I'm imagining about 1000mah but am not really sure?

[Andy]

Was thinking of buying a lipo with 11 volt and 1300 mah, not sure how good it would be but sounds about right

[duff]

I've just gone for a 4s 1300mah nanotech 25-50c. If you think that's overkill you should see the size of the spinner motor I just ordered.

[harry hills]

Someone else going for large motors then

[Ellis]

Ah yes, Harry here intends to form a blackhole with his brushless, or at least the figures suggest as much...

(am still trying to get a drill into a beetle design)

[Max]

I'm planning on using a brushless like this to power my fbs:
http://www.hobbyking.com/hobbyking/s...Brushless.html
Is that about what others are using?

[leorcc]

3 things about that motor.
1: it is a 380 size motor stuck in a 540 housing. This makes it running fast but it hasn't got much torque.
2: The bearing on the frontend of this motor sucks.
3: If you want to use this as a FBS power plant plan a good way to protect that 3mm axle or it will snap.

[duff]

Mine is similar size, weight and current draw, but its an outrunner with a much lower rpm/v and had a 5mm shaft.

[Max]

Ok, I've been looking at other motors as well but just wanted to check I was in the right range. I won't be connecting the shaft directly to the spinning element as it goes through a gear reduction of about 8:1. I'm planning to hav a ring running around the outside rather than a conventional fbs so that it is invertible, it just quite hard to get the power for the ring!!
I'm also planning a brushless drive but designing a single stage planetary gearbox to go on te end is also proving difficult due to the high rpm of smaller motors.

[Andy]

Trying to find a brushless with a good balance between strength and axle thickness, and torque, speed and weight. Havent found anything too good yet.

[duff]

I've found all motors below 200g tend to only have a 5mm shaft. I wanted an 8mm shaft but all the motors I could find were very heavy and a bit pricey. I'm planning on mounting the disc directly onto the shaft, but I see a lot of replacement shafts being needed.

[harry hills]

And probably a fair amount of replacement motors!
I'm running a belt reduction on mine to lessen shocks and to give the weapon a usable rpm

[duff]

Well, yeah, that too. I want to try and avoid using pulleys/chains though, so I thought I'd try it this way first. And if my motor explodes on the first impact, I'll know its time to buy some pulleys. As for usable rpm, my kv is already quite small, so if I do end up with a pulley it'll probably be 1:1.

Anyway, we've drifted a bit off topic here... Is anyone planning on using anything bigger than a 1300mah?

[PJ-27]

People use 1300mah for drive in FWs so should be more than enough in a BW even with weapon.

I'm using a 1.3 45-90C 3S Li-Po. Good for just shy of 60a continuous current.

[razerdave]

If the weight allows I'll have 2 of that capacity, one for drive and one for weapon (that S900 will draw quite a bit when it fires)