tipsy
July 15, 2020, 2:59am
41
You already have voltage(s_count), so the only extra field needed is either motor power OR motor amps, I’m not sure which one is more convenient from a UX point of view.
Plus, there needs to be a selection box for 1WD/2WD/4WD, since total torque doubles when you double the motors (if amps unchanged).
2 Likes
mmaner
July 15, 2020, 3:01am
42
Me either, Ill do some research and see which is more available.
Im glad you mentioned that. I wouldve hated to build all this and then realize I needed to double it .
2 Likes
I’d avoid the motor power ratings. They’re always inflated. I’d just use the set voltage (already done) and max amp rating calculated by cell discharge times p groups (already done)
1 Like
tipsy
July 15, 2020, 3:14am
45
But then we’re mixing battery amps and motor amps
example (single drive for simplicity):
setup 1:
20 battery amps, 80 motor amps
setup 2:
80 battery amps, 80 motor amps
both will produce the same peak torque (at low duty cycle), but setup 1 will start dropping torque at 25% duty cycle, while setup 2 will maintain peak torque all the way to 100% duty cycle (95% technically).
That’s why an extra input field for motor power or amps is needed for motor torque numbas
2 Likes
Even the Hoyt Drivetrain Slipped for you ?
1 Like
mmaner
July 15, 2020, 3:18am
47
It’s 15/36 isn’t it? But no, I’ve never had any slippage with it.
1 Like
I assume from their listing of the motor pulley it’s 12T:
Motor Pulley (Set of 2). Material: 1018 Steel with black oxide finish coat Width: 17mm Tooth: 12T Pitch: 5mm Shaft: 8mm Made in Portland, Oregon. Free Shipping on Domestic Orders. For international shipping, please...
Price: USD 29.00
mmaner
July 15, 2020, 3:25am
49
I’ll double check, but I’m pretty sure mine is 15t.
1 Like
Quick run down on what the hell motor parameters mean during detection, and how you can use them to help in your calculations
Resistance: The line to neutral (from ESC terminal to center tap of motor windings) resistance of each phase of the motor. This determines how much heat per ampere is dissipated inside the motor. The equation is approximately:
For FOC:
[image]
For BLDC it’s :
[image]
Where I is motor current, R is phase resistance.
This does not include things like bearing losses, …
Might be useful to add.
Flux linkage basically tells you everything.
1 Like
mmaner
July 15, 2020, 4:34am
51
Looks like I’ve got some studying to do. Thanks
1 Like
3ds calc was doing somethign funky confusing.
ahh yes. the calc isn’t paying any attention to how many amps your battery can send it to figure out max torque. try changing the p group size it doesn’t affect the torque numbers.
I think it’s computing max torque using the power rating of the motor and the max voltage of the system to figure out a max amps. and from there multiply by amps/nm x n motor x gearing
So that’d be max amps at max speed. II would think low end torque could be higher than that value. like torque/duty_cycle …
1 Like
Oooh that’s very much correct. Motor amps is the right choice. Don’t tell anyone but I set my motor amps higher and higher until they get too hot
3 Likes
mmaner
July 24, 2020, 9:00pm
54
Ok, made some changes (updates).
Added VTC6 cell values
Added 2 fields for user definable cells
Added save and load functions
Added a send function, non-operational for now
The send function is 90% built, but as the hosting is at GitHub I have no way of sending the data. I’ll eventually finish that function.
I have been doing some research on the torque values, it’s coming, I think, It’s just going to take some more work.
Let me know if there’s anything else you guys want to see.
https://mmaner.github.io/esk8calc/
4 Likes
Jujo
July 24, 2020, 9:14pm
55
Thanks for doing this Mike! Much much helpful resource
1 Like
mmaner
July 24, 2020, 9:22pm
56
no worries brudda, happy to help.
1 Like