so if i want to connect maytech 4.12 with focbox what should i do? just the CANBUS?
Do anything except CANBUS
Use split PWM (“PPM”) or dual PWM (“PPM”)
You can actually use CANBUS but you’d need to match firmware versions and there are a lot more gotchas
ok thank you
Realize that one side is going to overheat and throttle down much sooner than the other side though. But this is fine
but do i have to make the both settings same?
No, in fact the settings will be different. The 4.12 probably doesn’t want more than 25A - 30A “battery max” while the FOCBOX can do more
The motor numbers should match your motors.
Just set each one up like it’s on its own on a single drive skate.
Limiting the FOCBOX battery max to the same as the 4.12 battery max can make it feel more symmetrical and not pull to one side on hard acceleration
But really torquesteer isn’t that bad, you get used to it in a jiffy just like any other quirk of your board
i think of dual setup but one motor on front the other on back so i think it shouldnt be such a problem
Put the FOCBOX on the rear motor, on the heelside of the board
4.12 on front toeside
tru, thanks for help
Anyone here have nothing but problems with the pryside antispark? Today it almost took my battery and my car (lmfao) so it’s getting put out of commission but everyone else who has them hasnt had any of the problems I’ve been having.
If you’re doing dual diagonal, I would not even match these. Just run each one to its full ability
Mike is right, and I say that as someone who has a board each with eLofty original 58 KV DDs and a dual 6374 belt drive.
ELofty/cheaper DD drives:
My eLofty drives have been great for me, and up until recently, it’s been the board I grabbed first when going for a fun ride. But my cheap DD drives have been the exception rather than the rule. I’m on borrowed time. Also, I’m a bit bored with the fixed top speed on TB 110S.
Easy to build with. Plug and play. Work well with a number of ESCs, but best with vesc-based unit. Cheap.
Harder than you think to find a new pair without manufacturing flaws. 1:1 limits your performance/flexibility. Adapters aren’t as prevalent/easy to find as wheel pulleys. If a motor goes bad, finding/sourcing a matching motor may be difficult with so many variations out there.
The dual belts took longer to get right, but the rewards more than make up for the extra work. Offers far more flexibility. I can dial up stronger acceleration or top speed with pulley swaps. Plus, I have extra components for everything on the shelf if I need them. This board is now my favourite.
Performance, flexibility and ease of repair. Belts are a long-time proven performer and there’s a ton of options out there. You learn a bunch of things in the process of putting it together. Properly juiced dual 6374 power (or dual 6355 in your case-not a huge difference) is great.
Takes more time to tweak and get right. You need to source and acquire a bunch of separate pieces that come together as a whole. More expensive.
Surely its more efficient for the battery though? Drawing less amps from the cells is usually better right?
Having 12s instead of 10s indeed draws less amps from the battery for the same constant speed with no other changes, but since the vesc does a voltage change, the current in the motor is still the same. Since losses in the battery wires are negligible compared to losses in the motor, the increased efficiency caused by the reduced heating in the battery wires is negligible, because the same amount of losses will be happening in the motor. But if you don’t change the current settings, 12S enables more motor current at speeds when you are hitting the battery limit, because the same number of battery amps is more powerful at higher voltage. That increased motor current reduces the efficiency (but improves the acceleration) when you are hitting the same battery current limit on 12s compared to 10s. 12s also allows you to ride at a higher top speed, which in practive means you’ll be drawing more battery current on average with 12s to achieve those higher constant speeds than you could otherwise do with 10s, which also reduces the efficiency since wind drag forces increase proportionally to the square of the velocity.
The VESC doesn’t actually change the battery voltage. It only pulses it on and off digitally.
The magic lies in the pulse timing for the 3 phases.
If you’re drawing the same number of watts, then a 20% larger battery will mean 20% less load on a given cell. That’s not “efficiency”, that’s overengineering, or overbuilding, or simply leaving yourself headroom.
For a given vehicle, with the same motors, controllers, gearing, blah blah blah, 12s vs 10s gives you 20% more voltage and thus 20% higher top speed. Aerodynamic drag is a function of speed cubed, so a 20% increase in speed increases your top-speed power consumption by 73%. That’s not more efficient.
If you have a bigger (higher voltage) battery, you will have more energy to play with. But if you don’t adjust your setup to take the increased voltage into account, you will end up with worse efficiency overall, just like your numbers show. Your run at 12s used more energy per mile, than your 10s run did. It was less efficient.
Oh well I think this thread covers it in detail actually
The vesc indeed does change the voltage- the current in the battery wires is pulsed but the current in the motor (during a single commutation in bldc mode) is nearly constant…
for example suppose in your log you see 30a battery current and 60a motor current (50% duty cycle)… it means 60a is drawn from the battery half the time (30a), and 60a is going through the motor the whole time (at half the battery voltage):
^it’s a hard concept to understand but the on-off pulses from the battery are so quick that the inductive property of the motor, combined with the fact that the motor is shorted to itself during the battery off times, keeps the current flowing through the motor the entire time during the battery off times (there isn’t enough time between pulses for the motor current to change significantly), and if the duty cycle is 50% then the voltage of that motor current is indeed half the battery voltage.
the vesc really is lowering the voltage, and that motor current at lowerered voltage isn’t pulsed… it’s constant. it’s the battery current which is pulsed.
in reality during the on times, the motor current may be increasing from 59.9a to 60.1a, and during the off times, the motor current is decreasing from 60.1a to 59.9a. the inductance on the motor side (which is the property that keeps the current going without applied voltage, so to speak) is a result of the presence of the iron in the stator, and the coiled shape of the windings. the battery side has very little inductance because there’s no iron and the battery wires are relatively straight, so the current on the battery side can ramp up and down much more quickly than in the motor.
another way to think about the inductance is that there is actually energy stored in the magnetic field of the stator, and the collapse of the magnetic field when you remove the outside votage, “powers” the inductance, which keeps the current flowing for a short, extra amount of time.
So, you agree with me then basically.
You just typed a lot more