Ignore this
Ignore this
Last edited by Roboteernat; 31st July 2017 at 07:37. Reason: My post contained inaccuracies
The fuse is there to prevent lipo fires, not protect the electronics. The fuse rating is chosen to be somewhere over the maximum current likely to be drawn by all the ESCs simultaneously but less than the maximum current capacity of the Lipo pack.
The blade car fuses are a bit under rated if your bot has an active weapon, midi size fuses are what many builders use.
sorry i tried to remove my post but didnt see it come up, i didnt think anyone would read it before i got to work, looks like you did
ignore my post, i read rules 7.8.1
Okay... now I'm a little confused again... so would it be more logical to get a 100 amp fuse or a 90 amp fuse by that logic? Considering that the battery in question gives out 94.5 amps.
It depends on whether that 94.5A is the continuous or the peak rating. Most packs state both and the peak is usually between 1.5 and two times the continuous rate (if the peak rating is not much more than the continuous rate, its a very good sign of a low quality pack). If that 94.5A is the peak rating, I would go for a lower rated fuse, about half way between the continuous and maximum rates.
Well the math I went off of was the calculation from the FRA rules and regs.
The battery is a 35C series, and it does 2700 mAh, which is specified on the front of the battery.
Which means, by going off of the multiplication of that, 35 x 2700 = 94500. Which means by logic, that brings it to 94.5 amps.
It's Burst rating is 45C according to the hobbyking website. So if I make it 45 x 2700 = 121500. So that in logic makes it 121.5 amps.
Sp somewhere in between those two? I've looked at Halfords and their 110 amp fuse is a strip fuse, which doesn't seem to be the right kind of fuse... which is here.
Their 100 amp fuse however looks a little something like this.
And Maplin doesn't seem to hold any that's suitable for that kind of amperage from what I've seen.
All this math is making my head spin... why did I flunk my systems and control class...
The fuse is mostly to stop the electronics pulling too much from the lipo, lipo gets hot and then catches fire. So the rules say you must have a fuse for the maximum the lipo can supply, but in reality you won't get near that with a pair of drill motors. They pull about 30 amps a pair tops. So in that case you could put a 30 amp fuse in and roberts ya mothers brother. If you have weapon motors as well, add the current to 30 ish for the drive and buy for that. It's as complicated as you make it.
David, that's made things a lot more easier. I can easily find fuses as such in Halfords. And if not in Halfords, then I'll just look to ebay. Quick question... yes, I know, another one, but I always just want to make sure. One battery leading into a ESC controlling the two drive motors, will I need two fuses or just the one for that?
So that'd make my shopping list...
Shorter M6 bolts, as the ones I have won't fit the drive motor mounts.
2/3 fuse holders, one for the drive, one for weaponry.
2 30 amp fuses plus spares
24v strip LED lights
And a pair of wheels.
Once that's all done, I can get on to getting on with the weapon system.
Back at it again with the LEDs... Would connecting say... a couple of these just after the 30 amp fuse work or will the bulb just blow straight away? And will I need some sort of mounting board to go along with them?
My understanding of the rules is that you need one fuse and it sits between the battery and ESC(s). So following the wire along you have battery - fuse - Power LED - ESC(s).
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