Alright, with the proper cable - I’ve found that BLDC mode with ADC works just fine set to “sensorless”. I realized that when putting it to “sensored” it’ll only shake the motor and make a high pitched squeal when giving it more power.
Also, the braking isn’t exactly what I wanted. It’s much stronger than what it gave me in FOC mode, but nothing like what DC mode gave me. I’m thinking it may just be a curve because the motor is at low RPM (I don’t want the motor to be able to move when braking) but the motor seems the same no matter how I mess with it.
I tried DC mode again, and I found that two of the 3 wires connected to the motor get hot - so it indeed does transfer all the power through only two wires - and they get hot fast.
I also found that DC mode braking feels just like BLDC mode braking, and that DC’s “braking” is it actually trying to move the motor but… failing. It’s the perfect brake, as if its pushing the motor both directions so hard that the motor cannot move.
Setting ESC to 80 amps on DC mode makes the motor stand strong against any movement! It’s a forearm workout just to get it to move at all.
Now I just need to see if I can get that kind of braking on the other modes…
Also, suspect that BLDC mode doesn’t work with the sensors perhaps due to the cables needing to be connected in a certain order.
I remember when I first got the ESC, I was stumped by why the motor wouldn’t spin at all even though it would spin in initial setup. Solution was a different ordering of the motor wires.
yeah, don’t bother too much with experimenting with DC. You’ve got a brushless motor, not intended to work in DC, that’d be a shame to fry it at such an early stage in the project…
You can run sensorless, many people do, simpler, less things to go wrong. But that’s at the expense of potential cogging on startup.
Make sure you run the params detection for your motor. That will improve the way your motor is controlled, and that affects the braking. Detecting the sensors is part of it too, if you want to run sensored.
Braking will be stronger if you increase the motor Amps (in the negative range. -100A should be strong!)
and a bit like ABS does on cars, locking the wheel when braking is not always the quickest and most efficient way to come to a stop…
I’ve got it set to -100A. But when the motor isn’t moving, I can still relatively easily get it to move with my hand. But when in DC mode, that sucker won’t budge! I just want to get that kind of stopping power in FOC or BLDC modes, but messing with the curves hasn’t done anything.
Of course, I want the full stopping power when its not moving so that there’s no rolling.
From what I read / understood in regards to low rpm braking: the VESC will simply short the phase wires below a certain rpm range, meaning you only have passive braking from that point on. Kinda sucks, but explains why all VESC powered boards can’t really stop without reverse current control.
I would love to have active zero rpm braking via sensors/sensorless, kinda what Vedder showed in a video a few months back.
I’m learning a lot from testing the motor and such. I wish VESC tool had more in-depth controls, but I assume anything like that would require code. However, I think ADC with current/brake control will do enough of what I want.
I’ll first work a bit on my original project and then I’ll purchase the board materials for this project. Board materials ain’t cheap!
The best deal I’ve found so far on most things I’d need is this:
Which is honestly an amazing deal, as I’ve not found anywhere else that gave the pulley, belt, wheels, and truck for that price. My only issue with it is I wanted the 6" wheels, not the 8". However, no matter how I try to make the numbers work and where I look online, it’ll be at least $200 to try and get 6" wheels. The wheels with the hubs alone are $100 everywhere I look.
If someone knows where there’s a better deal, let me know. I’m building the skateboard from scratch - so other than the motor/esc/battery, I need everything else. I’m going for a compact skateboard - if anyone knows where to buy some good wood or such for the board itself, that would be helpful too.
I’m thinking of a square skateboard (?), though still thinking about it. Just trying to make something compact yet still have good control. At this point, thinking it may be cheaper to buy a skateboard that looks good enough and modify it as needed. Going for a stealthy board that I can ride on anything.
This skateboard is a side-project, so I really don’t wanna throw more money into it than needed.
Also, I currently got 4 weight sensors. I only really need one, but it may be possible to create an even more intuitive way of moving the board without a remote by have two sensors - perhaps a similar design to gas and brake.
Can’t test any of this until I get an actual board built, but with 4 sensors, there are definitely many ways to go about it!
I was just gonna limit the board’s speed while I test it, adding a remote seems like a pain. The cheapest remote are those huge things for RC cars and they’re $20. A decent remote was at least $35.
I could probably make my own remote with the materials I have around, but just doesn’t feel worth the time.
I’d say I’ll be careful, but that would be a lie xD. But I definitely won’t take any risk I think is too big.
Either way, I’m still looking for good deals on… pretty much everything. Trying to make a 6" all terrain compact board. Any links and ideas help!
For an off-roading skateboard, how small a deck would you guys feel safe riding on? I’m thinking 2ft long, 1ft wide. I wear size 11 and a half shoes, 1ft wide would feel nice, though maybe too wide.
I’m going for the smallest profile skateboard can I make while still being having good control and not falling over.