I have my dual focbox’s setup in hybrid mode. I was practicing drifting yesterday for an hour or so, from a stand still to full throttle while pushing the back of the board outside. I did this prolly a hundred times, hitting around 50 to 60 amps everytime, no issues. .
if it shows reliable maybe I would be after the insurance its practically the same price as the only two vendors who seem at all legit, axle and ollin,(diy wish it was more reliable but seems not yet) and those two come with assumed assurance. but they’re slow to get from if even available I think. ollin slow? axle I think is out for so long
still waiting for cheap and reliable to happen but more so reliable. Ive had them break and even with insurance Id rather not break. Or has it become assumed they will break at this point with these things
I’ve been trying to push dual FOCBOX on 6374s. So far I’ve been able to pull 35a max each by mashing the throttle sitting on the board. I’d just get tossed standing. I tried some uphill tests but the bumpy road to the big hill loosened my motor mounts so I just had belt slip trying to accelerate hard. Honestly if I broke one I’d just buy another? I’ve seen some complaints on the forum but it’s a good ESC for the price.
that brings up a longstanding question:
on current control you set the battery amp max, how come it doesn’t necessarily hit that current at full throttle?
With any electronic device, it will only use up the current it needs to work. The best way to make any ESC reach max amperage is to put a resistive load on the driven end.
but the throttle is creating the resistive load to a large degree, yet not all of it, no?. I can hit max throttle and the vesc will put out a much increased current because of that.
This was discussed here why for some when the throttle went full, the current draw from the battery was not at peak. Yes, you should get the total amount of current draw since a throttle press all the way to 100% should be a value of 1 or 100% on the duty cycle. I know the VESC itself has no problem. The issue is how torque is delivered from the motor over time, and that has been shown in the BLDC test curve of the unloaded motor. And then someone brought up a post when they went to hit the report command for the kV value on the VESC it was reported less than the stated value stickered on the motor. I’m not about to turn this post into a technical post since this is a reliability post about the focbox. Most discussion here never seems to stay focus on the topic here.
Place your skateboard upside down, Remove the belt and wheels off the motor and hit full throttle.
The motor will spin at max rpm. Correct?
How much power does the motor need to spin at max RPM? Not much, since there is no load.
This is called the no load power condition. This is equal to your battery voltage x your no load current. The no load current is proportional to the torque required to spin the motor.
Ideally this would be zero but in the real world there are losses. Your bearings, copper and magnets; they all have losses. Therefore you need some torque to keep the motor spinning.
I expect you to answer this:Lets say you only need 5A to spin the motor at no load. Why would your ESC draw 80A? Better yet, where would all that extra power go?
It is weird that you make motors, but don’t really know the basics of how an ESC works…
We’re running them at 12S in dual configs Keeping the settings to about half of their advertised rated current, they last a very long time. Zero issues so far. And they feel great.
The speed a motor is spinning will change its no load current draw so with 12s vs 10 or whatever it changes. but whatever and lets assume in youre scenario we’re not all of a sudden with a 20s battery and this 80amps isn’t partially being lost iron losses. So 80amps gone out of the battery I’d assume it ends up in a hill conquered and a hot bunch of wire in the motor.
but your question and talk of no-load current doesn’t help me understand my question and how with what is known as “current control” I can program the vesc to have 50 battery amps and yet not get 50 to happen with 100% throttle regardless of the terrain I’m on.
I’ll clear up the scenario:
Your board is sitting upside down in your living room with no wheels or belts, just a motor attached to your truck
You have the following:
10S100P battery at 36V (assume there is zero voltage sag)
ESC is in current control mode, and limits are set to 80A for battery and 120A for motor.
100kV motor.
Assume that at this voltage, no load current is 5A.
What happens when you hit full throttle?
What speed does your motor spin at?
Does the ESC command 5A, 80A or 120A to the motor?
Why?
I’ll answer these questions later for 3 different scenarios and hopefully you will understand how ESCs work