20s Little FOCers on stooge SRB v5#1 comparing to Castle based SRB v5#3

Actually my naive understanding I’d expect zero vector frequency to increase heat in the ESC, but should I expect it to increase heat in the motors?

Welp, i got almost the same track times on v5#1 (vesc) as v5#3 (castle). Then somehow I beat them both on the SRB super spine #1 with a single hobbwing 70125 motor and hobbwing ESC. that’ll make @MoeStooge grin. :smiley:

This past week the weekend session didn’t work however I got a session in last Wednesday.

I didn’t end up using all the motor amps (150/side) peak was 130A. and battery peak 54.5A (on one side. for some reason robo was back recording single side. )

It still felt a bit slow to deliver power out of a corner. but since i wasn’t maxing motor amps, this could perhaps be something throttle expo tweaking could fix.

of more concern, it felt a bit like the throttle ran on a bit sometimes when you let off. So I’m going to try swapping out the OSRR/uart remote for a GT2B so it’ll be more the same as my v5#3 castle setup.

Track sessions are a bunch of 2 - 5 min run, before pausing.

temps were not bad. and cooler than the street run temps.
Motor temps got up to 73c (161f)
Esc temps up to 46fc (115f)

v5#1 (vesc) 33.06s

V5#3 (castle) 33.03

SRB SS#01 (single motor, hobbywing max) 31.74

SS#1 has 45A rear tires, vs 50A i was running on the other two boards.

TL;DR;

throttle feels funny. switching out OSRR / uart for. GT2B/pwm for next session.

6 Likes

an update. it’s not gone… still there on the bench just perhaps not as obvious. still need to back out the zero vector/switching victory change to see if that changes the behavior back. still a fw5.03 problem which i’m still on for reasons stated above.

1 Like

Throttle still feels funny.

However, @MarioChacon rode v5#1 with the full size g2tb and said he didn’t notice.
I Didn’t notice as much I think it’s because the track layout held more speed with less acceleration this time.

I observe two things.

  1. doesn’t feel as initially punchy.
  2. if I do punch throttle hard it feels like it runs on more than i expect.

for #1 I used to assume it was max motor amps. but I haven’t hit that in the last two sessions (150A/side) again because the tracks have carried more speed, not hair pin to straight punch. and also I have to warm up to riding so hard I’m really punching and braking every line.

for #2 I’m thinkinga bout what @Titoxd1000 said. “throttle in the castle setup is duty cycle mode”. throttle in the vesc is current control mode. so current delivery is different between the two. and while I’m trying to get used to them both. I’m definitely preferring the feel of the castle.

in curernt control mode, vesc watches the current and adjusts the dutycycle to hit the target current.
in duty cycle mode, castle just sets the duty cycle according to throttle position.

I suspect in duty cycle mode throttle the current draw tapers off as the rpm reaches the target rpm of voltage * duty_cycle * kv so relative to that current contorl mode would feel like current continuing to push on.

ok too many words… blah. check yes if you like Moesha

3 Likes

was hoping to get a goofy footed binding on before tonights sesh. but not gonna make it.

1 Like

Wed night,
Mario shreded me on v5#1(vesc, no binding) vs my v5#3 (castle) but i didn’t get racechrono of it.
he also straight shreded me on the super spine single.
i didn’t really warm up. :smiley: excuses… lol.

me V5#1 me V5#3 mario on super spine
33.61 32.66 29.72

didn’t push new amp heights. more flow less slow corners into straights less aggressive riding.

8 Likes

dern. missed the night sesh because of being oncall for work.

2 Likes

And this is exactly why people street face when they ride the first time lol

1 Like

i slightly disagree here. people street face because they come from 3-5kw boards to a 12kw board.

the difference in these two throttle approaches is a lot more subtle. took me a while to even consider it as the difference i was feeling. and I’m not 100% sure … it’s just a guess.

2 Likes

I can see your point of view but having ridden a stooge on punch 7? I find it way harder to control than vesc (obviously I’m not used to it)

1 Like

“power level 70” roughly translates to max duty_cycle 70%

and, I can see your point as well. the control is definitely different. and my first observation “1. doesn’t feel as initially punchy.”

I’m now thinking this is perhaps because the current control mode on vesc is basically indirect. you give it throttle input. it translates this to a target current, then the PID control loop adjusts the duty_cycle to achieve that current, then monitors current and adjusts dutycycle some more.

with duty_cycle throttle on castle, presumably it’s much more direct.

2 Likes

yup turns out they are 173kv. sense made.

thanks @Skyart @Tony_Stark, Reacher for labeling these. @Evwan for mentioning it.

@Tony_Stark I assume the 173kv motor means the motor can handle 12% more amps than the 153kv. I’m still running 150A/side. above your recommendation (120A) but short bursts track use been ok so far.

and I haven’t gotten back to hard pull tests, been figuring out the remote issues mentioned above so i haven’t hit more than 130A/side anyhow.

2 Likes

from another thread. off topic convos about throttle difference between castle and vsec.

This definitely is power turned down. and brakes are often turned way down and with a negative throttle curve to avoid twitchy braking at high speeds. you don’t often brake quickly on street setups. overbraking on street boards is a thing tho when somethign sudden happens. this tuning on the stooge boards was to avoid that with all the sudden acceel and braking in hard track riding.

the braking setup like that is just by convention of how moe set things, and riders not changing what they got used to. it’s pretty dramatic difference from our ususal setups so i can understand this feeling.
which is why i continue to work on my own familiarity bias whilst feeling these things out.

ramp times are down to nothing. (noted above)

also not yet playing through throttle expo. which is the next thing people mention.
as at full punch it doesn’t make a difference. but i suspect it will even out some of the PID lag at low and mid throttle. based on feedback from others. so i suspect it can cover up some of the laggy response feel.

3 Likes

last Sunday 2023-09-24

ran chi track. ( see Chicago | T-Race - Global Electric Race Challenge )

EDIT: first time out with new gearing 18T/78T down from 21T/78T

motor temps getting 60c - 75c on 5min runs. definitely climbing the whole time. This might explain why the street run got to higher temps I just rode longer without a break. (Edit: or it’s the better gearing keeping it cooler this time) plus i still hear @Tony_Stark in my head saying i’m gonna cook em. xD

best laps v5 vs v5:

still didn’t put the goofy footed binding on.
it felt even more of a handicap on this track. and it shows in the best laps comparisons.

v5#1 (vesc) v5#3 (castle)
30.74 27.53

30.74 would currently rank 15th.

hey i beat @dskate :P, there you go. vesc beat out castle. just joking, not a fair comparison, @dskate’s time was from a fun run at night sesh

i peaked 9.8kw on v5#1

vesc throttle vs castle throttle both on g2tb remote.

regarding #1

“less punch” no new update. but I still suspect PID tuning, and that it’s the same thing that make people say BLDC feels more punchy on vesc.

regarding #2 “run on”

This time, having the discussion with @ShutterShock above in mind I felt like i could feel the difference and simply adapt better because i was expecting it.

and it definitely feels like this is the difference i was experiencing. Now that I’ve done a little getting used to both, I don’t think that part is too big a deal either way. but if you’re going through it you’re gonna like what you’re used to. That said, I suspect it’s possible PID tuning plays a role here as well.

future plans for throttle

  • get used to it some more,
  • play with PID tuning or expo settings.

still todo

  • get that binding on.
  • get back to testing harder pulls. again hearing @Tony_Stark in my head saying i’m gonna cook the motors.
11 Likes

I’m sure this has been stated but I can’t find it in the thread.

Are you running FOC or BLDC?

I believe @Tony_Stark runs BLDC. It might give you the “punch” acceleration feeling you are used to?

I compared them for a bit and found that I disliked BLDC. FOC was smoother, and BLDC gave me surprise “power boosts” on occasion. Not very fun for general cruising in my experience at least.

6 Likes

Duty cycle is like a on/off switch. While current control is like a dimmer switch, you only get full power at full throttle, is that what you are doing? My personal Gt2b mod has a shorter throw to make it feel more punchy off the line.

Did you ever change the gearing?

4 Likes

OH crap Yah I updated the gearing, forgot that update. this sunday was the first trial of it.

18/78T now with 49mph top speed.

6 Likes

running FOC. updated first post to state that. thanks.

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.

2 Likes

This is shockingly close to my bn gearing haha

1 Like

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

1 Like