How’s the 2-wheeler running so far?
1 Like
The 2-wheeler is running great. But I do have a question. I’m running it in FOC mode. I thought FOC would be quieter than BLDC, but I don’t think I hear the difference. Does this make sense to you?
2 Likes
Yes and this primarily depends on switching frequency and the motor being used. Large hubs generate more sub harmonics and are nosier. Increasing the switching frequenting shifts these audible frequencies to a higher pitch and going high enough eventually makes it inaudible.
Try bumping up the FOC switching freq to 25kHz and then maybe 30khz if that is still too noisy.
What motor are you using for the 2-wheeler?
Waiting on a matching mount from TB.
Trying to keep things nice looking.
1 Like
I think you can see from my pics above that that criteria had not occurred to me. 
1 Like
This make a world of difference, would love if the default was 30 kHz, or maybe most people can’t hear the pitch that the default 20 kHz make, for me it was the same until I cranked it to 30 kHz, wish we could safely go higher because a faint high frequency noise is still audible for me
3 Likes
There’s pros and cons to changing the switching freq. 20kHz is sort of the default. Going up or down may or may not cause issues depending on your motor and setup. It’s easy enough to just bump up the frequency in the VESC tool and try it out.
6 Likes
What kind of issues?
1 Like
Increasing the switching freq shortens the valid time the controller has to take a current sample. this is even more prevalent in low-side current measurement (inherently less opportunity to sample). Take a shortened current sample window and combine that with a low-inductance motor and you’ll start to lose accuracy in the current measurements (can lead to bad motor behavior). Higher inductance motors aren’t as bad since the higher inductance slows the rate of change in current and is easier to keep up with.
Going lower freq will cause higher audible noise but generally be easier on the controller to handle. The downside is the increased ripple current drawn from the large caps in the DC link. This will cause increased heating in the caps. If the caps can’t keep up with the ripple current demand, then they can fail. Lower inductance motors draw more ripple current.
8 Likes
I’m in LA and I’d definitely take one or two.
I decided to do a Group Buy Batch 2. Will also send a few units internationnaly (may take a long time) if anyone is interested.
3 Likes
Hello,
i am absolutly new in this things, i ordered an VESC 4.12 but now i saw this project (looks so nice btw), and i ordered 5 pcs.
Next week i am planning to build it but i dont know what to do after flashing the bootloader, how do i flash the firmware after that? (i am programmer of STM32 in my job and i feel so dumb atm).
Hope somebody can explain for an beginner.
Very much thanks from germany for bringing up this project so open for all.
3 Likes
No worries about the questions. You simply flash the .bin or .hex file of the firmware just like the bootloader. So first flash the bootloader, then flash the firmware, and then you’re done!
3 Likes
Thank you! I will give some review after building up these focers.
2 Likes
I was curious about that. Are the .bin and .hex actually identical files but one in binary and the other in hex format?
2 Likes
I’m pretty sure that’s the case. They are the output files when compiling the code. I’ve recently helped a friend program a CFOC2 and he used the bin files for flashing.
1 Like
Im looking at options for enclosures, really like the aluminium cases i also use for a200s and CFOCER1.
They are cheap (7€ for a single 12€ for a dual) and the heatsink is included. Mechanical protection is great too.
You can get them in all sizes.
122x85x55mm (its too high, i use this for the a200s):
122x96x38mm (a bit too large but the height is perfect)
It almost fits a dual setup:
This would be good for a dual:
5 Likes
That looks like very close to the 1590BB format I was planning on using.
“Stompbox” might be a more common name for people to find from other sellers.
1590B3 looks ok for a single.
Maybe a 1590U for a dual?
On ebay, I’ve found the 1590BB dimensions at 120x94x34mm or the 125B/1590N1 at 122x66x39.5mm
some of the stompbox options are also offered with “waterproofing” gaskets, though unless you’re grommeting power/phase leads, the benefits are debatable
3 Likes
If you really want waterproof, grommets won’t quite do the trick. You really need cable glands like this…
3 Likes
Can’t you mount one on the lid and the other at the bottom of the box? Like they would face each other when closed.
4 Likes