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Cheap FOCer! (VESC compatible 4.12 redesign)

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Hey there. I’m rehashing the VESC into a cheaper 2 layer version with external FETs. I’ll call it the Cheap VESC for now. You may notice it resembles the generic ebike controllers that you can find on ebay/aliexpress. This is a version that would probably cater more toward the ebike/e-scooter community but probably could still fit just fine on a skateboard. The primary goal here was to make a version of the VESC that is cheaper to create by reducing the original design to 2 layers (check out JLC PCB for super-duper cheap 2 layer boards) and reduce BOM cost a little. The secondary goal was simply to improve my own PCB layout and design skills by taking on this challenge. I still haven’t finalized the design but I would say I am at least 95% done with only a few minor problems to tidy up. I also have a thread on the endless sphere that I encourage you to check out. Feel free to make suggestions and ask questions. Note that this is my most complex board design for me so far with my previous experience being only with simple audio effect boards and circuits.

Cheap VESC

Advantages

  • Lower build and BOM cost

  • TO-220 FETs allow for big heat sink attachment for better thermal performance

  • SMD components no smaller than 0805 make hand assembly practical

  • Added ON/OFF capability to turn off control circuitry when controller is not in use. A simple mechanical switch will achieve this when connected to the “ON/OFF” 2-pin header.

  • Can fit in typical “350W” ebike enclosures

  • Can fit in Hammond 1590b enclosures

Disadvantages (that I know of)

  • Larger than original VESC. Cheap VESC is 45mm x 92mm

  • Higher profile with TO-220 package FETs

  • Additional assembly steps to beef up high-current traces. 2 layers of 1oz copper can’t handle the current flowing through during operation. Assembler will have to apply wire/solder wick/bus bar to the exposed Power, Ground, and Phase traces that you can see in the “bottom” image.

*Less than ideal layout for reducing loop area and inductance. Nothing crippling IMO but will be addressed in the future HV version.

Features of Future Versions (Calling them the High Voltage (HV) 6 and 12 FET versions)

  • Implementing DRV8353 for higher voltage operation (I estimate at least 20s capable). Will need stable version of VESC 6 firmware/software for the 3 phase current sensing and stuff.

  • On-board circuitry for no-spark connection

  • On-board Bluetooth capability for interface with Open Source Android app for the VESC

*A 12 MOSFET version with the FETs in parallel for even greater power.

*Experimentation with mineral oil filled enclosure for improved thermal dissipation. I am aware of potential wicking issues. I am aware that circulation improves thermal performance. I will be conducting a “before and after” analysis for seeing if it’s all worth it.

Further Notes: I intend to test the design rather thoroughly after I get a version assembled. I intend to power a motor under load with different loads while observing temperature with a thermal camera. I will test other features of the design to ensure quality. Because of all this, it will be some time before I release the design files as Open Source. I don’t want to give the community a broken thing.

See existing thread here https://endless-sphere.com/forums/viewtopic.php?f=7&t=97699

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.

https://vesc-project.com/donations

31 Likes

This is awesome. I would be interested to use something like this for bikes. Especially since I can attach to a massive heatsink.

What’s the estimated cost at the moment?

Just the board and BOM is $30ish USD if you use JLC PCB, LCSC, and get free samples from TI. You can make an account on their website and snag 5 free samples of most ICs. Also, you can get cheap STM32s the same way you just gotta pay for shipping. 3 STM32s were $9ish with domestic shipping from the ST site.

4 Likes

Hey

I was the person who invited you here on endless sphere, welcome

@b264

7 Likes

This is really awesome!

“VESC” is supposedly trademarked, so I would give it a different name and say “Based on VESC 4.12” so folks know it’s software-compatible

Maybe like TallESC or something

9 Likes

Great to have you here!
Finally somebody working on higher voltages instead of just pumping up the amp capability.
20s sounds crazy but would make the current 12s projects way saver.
Maybe I overread it, but what you think which currents your esc will be able to handle.

6 Likes

Wow 30$ is not much, im following this thread

3 Likes

30$ is dirt cheap…
Can we expect a simmilar performance to the flipsky vesc or tb?

1 Like

Watching this as well :ok_hand:

Guys, $30 is the board + BOM cost. Still need to add assembly, test, programming, shipping, margin…

2 Likes

He is making this possible by hand soldering

And it’s open source so you are free to make it for $30 if you wish

Compare it to a vesc 6 bom where the value is $60. Nothing stops you making it for $60 unit cost

3 Likes

Thanks for catching that. I’ll release it under a different name when the time comes.

I expect this to handle at least the same current from the original 4.12. Ideally it handles even more due to the ability to heatsink the FETs. I will be testing it’s current handling limits in a lab with a motor on a dyno.

This idk unfortunately. I’m not an experienced user of the VESC or it’s spin-offs so I personally can’t compare them. I will be having a few people test this design in their rigs to get feedback on performance.

Exacly! Thank you. This is meant to be cheap if you DIY. Prices for large quantity manufacturing is a different story.

I appreciate the warm welcome from everyone so far! I hope to have some initial results soon as I’m populating my first board today. Wish me luck!

15 Likes

Amazing! I would like to know what performance can we aspect from it and if it possible to make like a basic and pro version for a 12s,13s set up.

More current is always good, but what we’ve noticed around here is it’s actually the voltage limits that are constraining next-gen engineering. It’s the 60V DRV8302 that’s the #1 limiting factor

1 Like

I see this performing at least as well as the VESC 4.12 but probably better because of the ability to heatsink the FETs well. The future HV versions will be candidates for your “pro” versions.

6 Likes

Exactly. That’s why I’m looking at the DRV8353 for the HV versions. More voltage, More better.

7 Likes

The external fet is brilliant. I now start making some CNC work and it will allow perfect cooling.

1 Like

So is the BOM cost $30 if you are only building one board? If so, the volume cost should be $10. Or is the volume cost $30?

Well if you need testers? :wink:

1 Like

Yes. 1 board for the DIYer is $30ish. Volume would be cheaper like you said depending on which FETs you use and a few other variables.

Look for a PM.

3 Likes