VESC | Smooth acceleration from a stand still

Since I’m new to configuring VESC and didn’t see anything specific about this, i thought i’d start a thread for it for myself and anyone else.

I want to start from a stand still without kicking, but it seems like my motors are just jittering as i slowly pull the trigger. When i kick and squeeze, its fine. But i want to not have to kick. How do i do this? I’m not running sensored motors, so is it possible without them?

I’ve got twin R-SPEC 6355s on here and I’m using FW 2.7 FOC.

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That’s interesting. I’ve never used a vesc, but I thought one of it’s selling points was good startup torque using a special algorithm. Maybe the algorithm doesn’t apply to foc.

@longhairedboy I’m not the resident VESC expert, but I’ve been using one for a few months and with single motor I have always been able to take off from a standstill with only the tiniest bit of “jitter” when using the motor in “BDLC” mode. I’m assuming you’ve run the config for each motor already, correct?

Just last night I started using FOC mode and it’s the smoothest startup I’ve ever experienced. If you haven’t tried FOC already, start there!

You can bump up the “startup boost” value a tiny bit and that might get you moving from a standstill more easily.

Also, are you giving the throttle enough juice to get moving? I’ve found that w VESC the throttle curve is very progressive. Can you get moving if you “gun it” a little more?

Huh, I can start from a standstill no problem with the VESC and a single enertion 6355.

I’ll post a video this weekend (if I get to it)

ok Sorry for the false alarm!

I was just too terrified to squeeze the trigger enough. I admit it. This build scares me. lol

Luckily i got a full face motorcycle helmet recently for free.

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@longhairedboy I’ve found the “Soft RPM Limit” in VESC (in the PPM tab) to be a huge help when I’m testing. By default it’s set without an effective limit, so bringing it down (I use 25K-30K) means full throttle won’t be a scary speed. Then you can crank it higher once you’ve got everything resolved.

soooooo sweeeeeeeetttttt

@treenutter i’ll check that out. Thanks for the tips!

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@treenutter which steps did you follow to set up FOC ?
It’s only after your post yesterday that I realized FOC also works for sensorless motors !

i havn’t yet. i tried simply enabling it but that was a terrible idea. thy just went in all different directions and stuttered. I’m not sure yet what values go where for FOC on these, i’m still digging around.

if anyone has known good FOC settings for Enertion’s 6355 190kv, post them here. I would like to export a known good XML file with FOC enabled and anything else setting wise that can sweetly tune these motors to buttery goodness.

I think either OKP or WhitePony from ES have used FOC with dual R-Specs, so I might check their build threads too.

also i’d like to hear about or even see for myself what’s possible with these in combination with VESC.
product/electric-skateboard-motor-6355-230kv-2650w/

@torqueboards basically has racing motors on his site on sale.

@longhairedboy Slowly working on that, patiently waiting for onloops wood-cf deck and doing some layout mods to the vesc to directly use the motor sensor without changing the connector. All this bldc controller research i’ve been doing convince me that i need a eboard.

[Here] 1 is a post by okp on ES with the steps to setup the FOC parameters.
Tried it on the R-Spec @12S : failed. Back to BLDC mode.
I don’t feel like mucking about in all these settings without knowing what I’m doing so either I start reading up on FOC or I wait till some friendly soul finally figures out how to do it and posts a decent step by step tutorial.
I don’t even know if it’s worth it. Less noise ? Don’t care.
More efficient like in better range ? Do care.

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I just ran the tests then applied the settings that the program discovered. Once that was done my board was amazingly quiet and will now barely stutter at all when starting from a standstill. Breaking is quiet too.

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@psychotiller in which order did you run the tests ?
When I try to measure R & L I get an error “R is zero, measure it first”.

@trbt555 Sure. I’ll list the steps I took when I’m back at my “bench.”

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I had pretty much the same experience. But I think I need some tweaking to get the brakes just right.

I did the steps in order of appearance. Top to apply button

How long are the battery cables between capPCB pads and your battery? They should not be longer than 20cm for FOC, I had the same error (and some more) when the cables where to long. BLDC is less sensitive though.

@elkick would the effect of long battery cables be reduced if using more capacitors in parallel?

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