Battery size

[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)

[Max]

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)

I'd wire the 2 batteries in parallel- that way you have more Amps available for the s900 rather than trying to draw too much current from one battery.