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Cheap FOCer 2 (Open-source, Low-cost, VESC 6 based ESC) (v0.9 Release. Beta testing ongoing)

:warning: DRV8301 chips of lot number 88ASYCTG4 suspected of high failure rate
Several users and participants of the CFOC2 v0.9 has experienced failure from DRV8301 devices of lot number 88ASYCTG4 from JLCPCB’s SMT assembly service. This was originally thought to be inadequate soldering but has since proven to be something more complicated. This particular lot has shown to have a high failure rate though not necessarily always failing. Symptoms exhibited are audible ringing from the inductor close to the DRV (L1), deregulation of the 5V output from the DRV’s buck converter, and subsequent catastrophic failure of anything connected to the 5V rail (CAN transceiver, ESD diode, 3.3V LDO, ect)

@doomy has discovered a test to recognize bad units before powering on. On an unpowered CFOC2, perform a diode test with a multi-meter that has this feature from supply positive to supply ground and then reverse. Results should be close to the chart below
NEG - POS + 2.615
NEG + POS - 0.555

NEG - POS + >3V
NEG + POS - 0.576

I am attempting to track down this particular lot number all the way to the manufacturer to see if this was a known bad lot that somehow ended up in JLCPCB’s stock. If you have been affected by this occurrence, I encourage you to contact JLCPCB’s customer support and seek a refund for the failed DRV units.

v0.9 released on GitHub. Beta testing ongoing with success so far.

I’m happy to finally announce the v0.9 release of the Cheap FOCer 2! Special thanks to @bj97301, @NuRxG, and @Davewesh for formatting the repo into something truly outstanding, much better organized, and readable by humans.

Remember that this is still being beta tested (although successful so far). Myself and the other contributors to this project will be making tweaks as we go and as we receive feedback from the community. I hope this community enjoys having this open source hardware available to build, use, sell, modify, and improve.


  • 35A continuous and 70A peak with good heat sinking. These are real values. Not marketing numbers
  • Up to 50.4V(12s) safe operating voltage. For 20s version take a look at these FOCers.
  • Compatible with the VESC Tool for configuration
  • Open source enclosure design to come
  • “Living” LCSC BOM to come. BOM document to be continuously updated with compatible and stocked components from LCSC

Advantages over VESC 6

  • Significantly lower build and BOM cost
  • TO-220 FETs allow for big heat sink attachment for better thermal performance
  • 2-layer PCB that enables low-cost manufacturing from JLCPCB
  • Designed with JLCPCB’s SMT assembly service in mind
  • Added optional ON/OFF connector to turn off control circuitry when controller is not in use
  • CAN connector changed to 2-pin to avoid improper connections that can cause damage
  • ESD protected I/O
  • Hardware open sourced
  • Designed with direct meme integration

Advantages over Cheap FOCer 1

  • VESC 6 based instead of VESC 4.12
  • Significantly improved layout to reduce current loops and facilitate low-noise operation of both the power stage and control circuitry for more stable operation
  • Has IMU for balancing applications
  • Lower profile
  • Handles lower inductance motors much better
  • All components on the top side except MOSFETs
  • Addition of JST connectors to replace pin headers for Servo, CAN, COMM, ect.
  • Addition of header for unused GPIO pins
  • Micro USB

Disadvantages (that I know of)

  • Larger than original VESC 6. Cheap FOCer 2 is about 60mm x 120mm x 14mm without enclosure/heat sink
  • Uses custom firmware that’s not currently supported in the VESC project. Will make firmware available on GitHub until Cheap FOCer 2 is added to and supported by the official VESC project.

All this wouldn’t be possible without Benjamin Vedder’s hard work to build on. Please consider supporting him for his efforts through the link below.

** Funding for essential materials has been achieved but I’m not stopping anyone from helping out. Anything you toss my way helps with unexpected costs and/or helps get this project to completion**


Oh shit first!

This is so cool. Will definitely take a crack at this. Thank you @shaman!

EDIT small donation sent.


Much obliged good sir :slight_smile:

1 Like

Will this “cheap FOCer 2” be another diy esc where the user has to order the pcb and parts and solder everything themselves?

Or a production unit someone can just buy off shelf?

How much is the estimated cost?


This is supposed to be another DIY option. Once the files are released you can use the SMT process from JLCPCB to get the boards made probably 80% of the way. The other 20% is any missing SMT stuff and the through hole components.

With this design, and some additional discussion with @shaman I may order several of these and finish/test them myself and function as a distributor and support for those that want a ‘turnkey’ option. I haven’t decided if that will be something that I do or not. If I do, it will be with Shamans blessing and any pricing id give now would be in poor taste without greater discussion.

Furthermore any ideas or offerings that I have regarding this will not surface on this thread until such a discussion with Shaman has been concluded.

To reiterate - this is a DIY kit, no off the shelf offering from Shaman. Estimated cost wasn’t announced here and therefore its likely in flux until after the beta is finished hence it was not mentioned.


@Davewesh is correct. I don’t intend to sell these outright. I intend to enable individuals to make this for themselves or develop some arrangement to create completed units for others. Pricing is hard to gauge this far out but I’m looking at about $250USD worth of materials for a batch of 15. This is the reason I need funding. These 15 units would be for quality testing in various applications. I really wan’t the Cheap FOCer 2 to have good data supporting it’s release to the world.


Keep up with the good work!
Donations sent :relieved:


Wonderful! Much appreciated :+1:

1 Like

How much funding do you need? How about doing like a kickstarer or something?


I think this will take a large portion of the funding away ):


I don’t need in an ESC right now, but I’m happy to support genuine development like this as I do for Vedders development. :kissing_heart: Keep up the work, happy testing!
Donation sent.


I’m very interested to see the work involved to put one together. It would be nice to be able to make several in a day.

1 Like

Donated, let’s make these real.


I don’t need enough to justify a Kickstarter or anything like that. Just a bit to help cover the $250 of materials to make a test batch.


Thanks @Brenternet and @Narnash! So close to ordering the materials now


Even closer now :slightly_smiling_face::money_with_wings:


I appreciate that @M77!

1 Like

Thanks everyone else too. I see you there on the PayPal :slight_smile:


Goal reached! This community is amazing. It took only about 24 hours to make it happen. Will be ordering materials later today or tomorrow!

Happy Thanksgiving to everyone! I am certainly thankful to all that gave for this project!


Glad to hear it, looking forward to what you build.