FOC Mode with Sensored motor

ESK8 Electronics
, , ,
1

Hi esk8 community, Now that Ive got all of my parts coming in the mail, including a:

  • 80a continuous discharge BMS
  • The Sensored DIY 6374 Motor
  • The DIY VESC
  • 5x 2s 60c 5Ah Batteries

I now have started to start planning and learn about the Vesc settings. After reading through as many of the FOC and BLDC threads that I could find, such as these:

I have some questions that I would love answered.

  • Number one on this list is if I can use sensored motors on a BLDC setup. Ive read bits and pieces about this but have yet to find a clear answer.

  • Secondly, I was recommended by a fellow community member to follow this guide by vedder in setting up FOC

If i follow this setup guide to the T, testing the motors and all of that, will I have to adjust any other specs? The reason I ask this is that I have seen multiple people mention parameters such as breaking or regenerative breaking. I do already realize that I need to put in the specs of my specific battery config and current.

  • Lastly, do any of you experienced builders have any recommendations with how I should go about the setup?

Thanks, I really appreciate the help.

2

First of all I don’t know if the DIY V4.12 is good for FOC, someone else maybe chime in.

Of course, it’s called hybrid BLDC mode (the startup performance is better with FOC but with hybrid you have better low RPM performance than normal BLDC)

The BLDC Tool is outdated, download the latest VESC-Tool here The VESC-Tool has wizards and it’s easy to set up.

You can find infos and tutorials here

You can find all explanations for the settings in the link above, some possible start settings for your case could be:

Motor Current Max 60A (you could rise it up to 80A) Motor Current Max Brake 40A Battery Current Max 60A (don’t go higher) Battery Current Max Regen: 20A (if your Lipos are 5c charge rate then it’s 25A, 20A is safe)

Battery Cutoff Start: 35V Battery Cutoff End: 32V

These are the main settings you have to change in VESC-Tool (it’s in the motor wizard), then start app wizard

But power and connect your vesc first, start VESC-Tool, update the firmware and then run the wizards.

I like that you go this route but please only connect it when you fully understand how this specific BMS works and how to connect it properly.

Good Luck!

4 Likes
3

Also to save you from some trouble, a lot of people have broken their diy vescs by running it in foc. To be safe, sensored bldc mode should be more reliable.

4

Ya, from what ive heard from various people so far, youre right, the FOC, unless you know what youre doing, might not be worth the risk.

1 Like
5

In your opinion, is trying to get a FOC system set up not worth the risk? Have you personally used FOC on any of your boards? And lastly, I have to use the BMS because I did not opt for a balance charger but instead when for a bulk, 4a charger. Also, the BMS is the only part of my board that I have the e-switch connected to.

Thanks for your help, your reply was very informative.

6

Yea, blew my diyesk8 vesc the second I press detect. I am not gonna try foc unless I am using an foc box :package::sweat_smile:

1 Like
7

I have a diy vesc in foc sensored and it’s completely fine. I’m following namasakis build but with a single 6374.

8

How many miles have you put on it so far? And I’m also following his build. Are you using 5 2s 5Ah batteries?

9

Couple hundred miles, I recently went sensored but with no sensor it was still good. And yeah, the only difference is that I made a series adapter for the batteries.

10

Honestly if you follow the steps you’ll be fine. I don’t see why people hate diy’s vesc, haven’t had a problem with it.

11

Considering it sounds like we will have a extremely similar setup, any chance you could screenshot the values that you use for the FOC mode? Also, i considered doing the series adapter but in the end, i think im just going to solder the wires together instead of using an adapter. If you dont mind me asking, what are the specs of your build?

12

90mm clones, 10s1p lipo 60c, hobbyking mount, 80 a bms, 190kv 6374 tb motor

13

Yeah I would solder them together, it’s just at the time I didn’t have a bms so I never changed it. Im not home right now but If you scroll to namasakis settings it’s exactly the same. -20a for batt min will be fine for our batteries

14

Interesting, I have the same setup 10S Lipo, DIY VESC and a single 6374. It’s been running fine during the few tests I did. Running BLDC mode, sensored. I was hesitant to try FOC as I feel like it’s kind of the lottery, either it works fine or it just fries. What’s your weight ? And what’s your average speed/top speed ?

15

Ya, my setup will be 10s1p lipo, diy vesc, and a single sensored 6374 motor. From what I have been reading, if you use the new vesc-tool with the upgraded FW then moving to Foc is alot safer and less likely to kill the vesc. I would love some input from an actually experienced builder about the new tool though

16

Did you use the the old bdlc tool or the newer vesc tool to set up the foc

17

around 190 pounds. With foc its a little slower but my highest is 26 and i think i still have room for more, with an average of about 18-20mph.

1 Like
18

old, I found it easier at the time. I went foc because I was curious and everything worked out fine.

19

In your opinion, how much speed do you lose with the foc instead of bldc?

20

you’ll notice a difference, but I doubt you’ll be going that fast all the time. If you want to sacrifice speed for a quiet start up, go for it.