20s Little FOCers on stooge SRB v5#1

[fessyfoo]

@ShutterShock

This is shockingly close to my bn gearing haha

those BN gears are nice in hand. i hope to get them on my lonestar with 3link adpatation sooner than later. … but… i’m on projects.

[Shadowfax]

@fessyfoo

surprise power boosts because of BLDC sounds odd.

@Tony_Stark played with the pid tuning of FOC for some directionally positive results. so that’s where i got this notion and what’s on my backlog to look into.

because technically FOC should have better torque due to no torque ripple of BLDC.
and people make the same complaints about FOC vs BLDC that i’m making about duty_cycle(castle) vs current throttle control.

Yeah the BLDC “power boosts” were odd. Every once in a while it would feel like I had kinda bumped the trigger, but I knew I hadn’t because the effect completely went away switching to FOC.

Andecdotally, people swear up and down that BLDC delivers more power. Since you are really the only person here who has experience pushing both SRB and VESC setups, I think it would be worth trying out BLDC, to see if you can get the punch that you are after.

I think there is a hybrid sensored mode for BLDC (uses sensors only for low ERPM), so that you could still do launches for testing.

[Tony_Stark]

@fessyfoo

if I do punch throttle hard it feels like it runs on more than i expect.

If you are using hoyt puck in right hand, try putting puck into reverse and then hold it backwards in your right hand with buttons facing palm. This will remove the built in throttle ramping providing significantly better response and takes away that feeling that the throttle runs on more than you expect. I can’t ride with the puck in normal orientation because the throttle just feels disconnected from me.

And I run FOC these days. Got it working much better than BLDC.

[fessyfoo]

I’m not using a puck. In this case. Was using OSRR. Now using G2TB to be same as reference board v5#3

[Tony_Stark]

It’ll be PID related then. Has same effect as ramping time

[fessyfoo]

@fessyfoo

still didn’t put the goofy footed binding on.

finally fess… 'bout f’n time.

[fessyfoo]

Saturday 2023-09-30 Intro2Speed SD

THIS BOARD IS REALY FUN

First day with a binding. I felt way more confident on the board.

I think this thing is a contender. Tho I only hit 9.8kw and my times were beat by @ShutterShock, Reggie (v5#16), and Jack (16kw bro on srb trackpack) and myself on v5#3. it feels pretty damn good. it was also at a traction disadvantage tires wise, and I loaned it out to Gialong and didn’t get to set a better time on it which I think i could have.

This course had a long straight that I should have gotten more pull on. but my confidence in me was low today.

v5#1 (vesc) early runs	v5#3 early runs	v5#3 warmed up runs
34.60	34.74	32.73

9.8kw

motor temps up in the 80c range.

Gialong ran a lot more laps in a row than me on the board, and temps got up into throttling zone. hmm. probably means they’ll get hot at an AVS style race too.

throttle

run on

I’m more convinced the “run on” feel is just the difference betwween duty_cycle control and current control and that you need to adapt to one or the other.

I could feel it as a very obvious difference down the straight coming to the end. you wouldn’t feel it if you are throttle on then off all the time. you feel the difference when you slow thrust to maintain a speed. on the current control you have to let the throttle back a lot further. I also felt it through a series of corners after switching from vesc to castle back to vesc.

Switching is hard, you get used to one and the other feels different.

#2 less responsive

the “less punch” i’m going to switch to calling “slightly less responsive”. it was there but didn’t bother me as much today. I think you have to be really in the zone and pushing the limits to notice the difference. and I wasn’t in the zone much today.

[zero_ads]

I think you meant @ShutterShock ?

[fessyfoo]

@zero_ads

I think you meant @ShutterShock ?

I did. fixed. thanks.

[dimos15]

Nice, thnx for doing this!

@fessyfoo

motor temps up in the 80c range

xcell claims the turbines can do 150amps continuous have you tried them?

[fessyfoo]

I have not tried the turbines.

[fessyfoo]

skate status

no sessions for me. life stuff getting in the way.

PID control.

My VESC package, Trick and Trail, is now available (for self-balanced boards)

The primary innovation in the Trick and Trail Package is the throttle and brake control. In Balance and Float Packages we see that the throttle and braking control is governed by a PID loop. PID stands for proportional, differential, and integral and these factors apply to the board angle and cycle time to determine the current output. In general, boards that feel unstable have high differential and integral factors. These factors are time related so that the more time the board spends at a cer…

this is interesting seeing one wheel app kinda deciding to tune PID control all the way out. if i super paraphrase, “to get a better responsiveness” from it.

especially interesting to consider since we’ve been comparing esk8 throttle duty_cycle control vs current under pid control here.

[poastoast]

howtdoyousetyourboard to BLDC?
for

research purposes

cause i miss it

a lot

i can’t figure out how to run detection then have it be bldc

[fessyfoo]

idk. I’ve only ever used foc on vesc.
isn’t it just set motor type to bldc, then detect bldc parameters?

[poastoast]

i gotta see how it’s done

cause i can set to bldc but there’s no way to run parameters… unless imm dumb and blind

and they removed it from the wizard

which isn’t bad but it’s sad

i must find a way

[fessyfoo]

@poastoast

and they removed it from the wizard

well there’s the non wizard detection pages in the app.

[poastoast]

i’ll mess around on friday, hope i din’t blow something up

[b264]

@poastoast

i can’t figure out how to run detection then have it be bldc

You have to do a manual motor detection to use BLDC, don’t use a wizard

[poastoast]

yup, if figured

i want it

[fessyfoo]

@fessyfoo

are you both saying motor heat is a function of erpm?

@Tony_Stark

Yeah iron loss is the primary cause of heating in this motor

@Skyart

Not ERPM necessarily but just RPM

been thinking about it being rpm and not erpm since skyart wrote this.
kept thinking it’s got to be ERPM because that’s related to the number of times the magnetic field changes

@Shadowfax

Although iron losses will be higher on 20 pole motors vs 14 pole, because higher ERPM. With 20 pole motors you have 42% more ERPM vs 14 pole, at any speed.

And this seems to concur.