Cheap FOCer 3 (Open-source, Low-cost, VESC 6 based ESC) (In Development)

The next round of prototypes are done and about to ship to me. Then I can continue progress.

FYI, another secret project of mine that uses similar architecture and components just passed a road test at 140A motor current with a 16S battery on my ebike. I expect similar performance for the CFOC3

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Just a matter of gate drive tuning now. Was hitting some good milestones on the bench. Tweaking Rgs and Cgs values to get those good rise/fall times. Stability is priority!

MOSFETs exhibit slight ringing on the gates during turnoff. Not used to seeing this specific occurrence. Might have something to do with the older SGT architecture of the MOSFETs. It’s not beyond control but just interesting to me.

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Hey, this thing looks exactly like something we would need right now!
Looks awesome!
I have two questions: Is it going to have support for uart to bluetooth? Pwm input at the same time?
Everything is going to be controlled via vesc tool?

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So it’s like most VESC based controllers. It has the same features as as your typical VESC but without built in bluetooth. You’ll have to add your own BT module

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Hey there, can you already tell me what FET’s and Fet driver you are using for the cheap focer 3? I want to redesign the version two because I need a little more power. Or do you guys have any recommendations for 20s >100A controllers?

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There is a list here

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I have the Little FOCer for this kind of thing.

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Test unit did up to 140A on the bench with 16S battery. It’s now time to toss this unit on something for field testing. If that goes well, then I’ll crank out some more test units for other testers!

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Just did a test ride on my ebike. 16S, 120A motor, and 60A battery. No issues. Will crank up to 140A for round 2

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Using a Kranked Motor ?

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No but that would be cool. My ebike has a MXUS 3K Turbo hub motor

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Going to Ben Walker in Switzerland tomorrow and bring him his Kranked Kit.
He is also working on other bikes and ordered a lightning-rods motor
I think he has also a https://www.revx.cz/

If you are looking for someone testing he can do it.
In Champery they have steep trails.
He can do 5000 ft uphill on full power.

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Yeah I’ll have to see if the CFOC3 fits for his rig!

CFOC3 beta units finally outbound to testers!

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Not sure if anyone has asked but do we have a confirmed size for these? They look pretty big

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Maybe not the right topic but Shaman have you ever worked on very low power BLDC systems, 5W or less? I’m trying to work out which if any approach would work for a project. It seems there’s a decent market for highly integrated ICs with FETs onboard for computer cooling fans so that’s easy enough but they have some power limits, and I can’t easily find gate drivers suitable for such low power. The gate drivers seem to start at higher voltages.

Any experience with small stuff like that? I can’t seem to find any existing projects other than this smart knob so I can copy their homework

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When the idea about cfoc3 was first brought up I understood the board size and hole dimensions would stay the same to keep the unit compatable with with CFOC2 powered devices.
@shaman can you confirm will cfoc 3 stick to the previous gen board size and hole layout, or will it be different?

Also I’m super excited seeing these coming to fruition so fast. Keep up the good work!

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Same PCB size as the CFOC2 but now the caps are over the PCB actually making the footprint smaller

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Boy - I made a major mistake when trying to determine dimensions from the pic. Thanks for the response.

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thats pretty chonky sheesh :eyes:

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