Even though I despise the locked down FW approach wondering if Flipsky actually had a non nefarious, technical reason as to why they would only enable FOC vs BLDC.
I quickly tried Hybrid mode and BLDC mode but had some issues. First, I get this strange condition where USB while using VESC tool. The USB port seems to freeze up once the motor draws any current. I have to disconnect and reconnect USB to regain communication. Problem is intermittent and happened on stock FW as well as the Hacked FW. I have two 75100 controllers and it’s happened to both.
I’m pretty competent with these sort of thing as well, Im positive it’s not created by a wiring error. Been an industrial electrician/electronics tech for +25 yrs plus Ive been active with electric RC since before brushless motors and Lipo were even introduced. Motors,motor drivers/escs and batteries are stuff I live for. Lol. VESC is admittedly different than anything Ive done before but only with the app side. The rest of it is straight forward.
Yeah, we all know this. The word " hacked" is just being used for lack of a better description for it. Jaykup did figure out a way to get it working though so technically it is a hack.
Mostly true. I had to figure out what configuration settings they used and you can see my comments in the hw_75_100.h file. Things like resistor values for the input voltage divider, shunt config and resistance, beta values for the NTC sensor by measuring resistance at different temperatures, pin mapping for communication ports, etc.
If I got any of that wrong it won’t perform correctly, and I also don’t know if they made any changes to the core firmware that changed how certain features worked.
But yes, they did steal and are profiting off the hard work of an open source project without doing the bare minimum of releasing their changes to the source code.
Was thinking,. I did redo the wiring to eliminate all possible high resistance connections between the battery and motor in-between the FW change. I originally had a few extra XT 60s to create a series connection between my two 7s batteries. I eliminated those and soldered together the stock 4mm barrel connectors between the motor and ESC. No sign of heating with any of these connectors but…
That could account for the performance increase between stock and the hacked. Everything else was equal in FW settingg.
It’s possible the USB cord you are using is too small of a wire gauge, or they are using a poor buck converter. I can test to see if I run into the same issue.
I couldn’t get BLDC sensored or BLDC hybrid mode to spin the motor properly but that may be a configuration issue rather than a controller limitation. BLDC sensorless worked well. All FOC modes worked including HFI/VSS.
I couldn’t reproduce the USB issue. I had a stable USB connection using FOC and BLDC under load.
Does the lower speed range, below vanilla max speed where FW shouldn’t be active, still feel the same to ride? Even on a board with 80A phase current and big chunky motors I’ve always disliked high speed gearings, the feeling (this is the vague bit) has always been a bit more spongey, almost laggy. If this could be an option to have the low gear feel 90% of the time and the possibility for a higher top speed I’d be delighted
Also sorry I know you mostly tested on a bike so maybe the whole feel doesn’t translate well anyway or you might not have as much experience to use as a reference
Yup, you have it right. There is no difference up 90% duty cycle (~90% of top speed). The setting “Field Weakening Duty Start” is set to 90% by default, so only the top 5% has FW active up to the 95% max. Gearing low with the option to “boost” using field weakening is absolutely what I was thinking of with that feature suggestion. If you gear too high it will feel sluggish, and it doesn’t take much. A single motor board geared to 27mph feels significantly faster on acceleration than one geared to 34mph.
Funny enough, about a week before I mentioned that, someone else put that in as a feature request to the VESC GitHub so who knows, it may happen.
Just got back from a 10 mile ride. I came across a steep hill that I can’t get over 90% duty cycle on and thought it would be fun to test your question. I climbed it with 35A FW, then 0A FW. Same 15 seconds up the hill with the same amps/watts… so yeah, same performance under FW speed even with it active.
It’s fun with all the extra speed, but man the 50wh/mi is killing me lol
Should work great as long as it’s mostly flat. I’m curious what your continuous amps will be with that big heat sink on there. After several miles I keep thermal throttling down to 35A, but I’m guessing you will get closer to 40-50A.
I can confirm that a 10k NTC thermistor with a beta of 3950K read the correct motor temperature when that was setup in the app.
Are the other controllers VESC? What is the multimeter ohm reading? Maybe the connector wiring is different? Do you have the same issue on the stock FW and hacked FW?
Other controller was FSESC 7550. Multimeter reads 11kOhm for the thermistor at room temp. Thermistor and 10 kOhm test resistor read at about -10C. Disconnected (open circuit) reads at -67C. Beta value 3900.
This is with 5.3 binary. Can check stock firmware in next couple of days.
Some ESCs have different hall sensor connector orders. Flipsky had errors in some of their schematics. I updated the main post with the correct schematic.
Edited out the vesc image as it’s too old to be relevant
