UPDATED SUMMARY
This controller works for it’s original purpose to compete with cheap ebike controllers. It was beta tested by a few esk8ers and ebikers. The Cheap FOCer works ideally with higher inductance motors, such as ebike/escooter hub motors, but still has functionality with outrunners.
The Cheap FOCer 2 is released and recommended as the superior alternative to the Cheap FOCer 1.
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
Runs cooler than other VESCs
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.
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.
Building off of Benjamin’s shoulders isn’t free either. It takes time, money, and lot’s of analysis in the lab to do it right. Anything you can toss my way helps me a ton in ordering materials for R&D.
GitHub repository for the gerbers, schematics, and BOM
I’m creating this new thread to continue off of the old one from esk8 builders. If you are new to this project, read the summary below for the gist of what’s going on. You can also click the link in the original post that will take you to the original thread.
Summary:
I did my own take on the VESC 4.12 hardware by designing a 2-layer PCB for lower cost and using TO-220 MOSFETs for better thermal management. I made an initial prototype by hand, did some analyisis on it in the lab, found some problems, fixed the problems (mostly), had beta versions made, and the beta testers are currently providing feedback. So far so good with the beta testing and I’ll be posting some of those results here.
The initial problems were mainly due to bad layout of the main power and ground traces. I learned that bad layout of high-current traces causes a lot of parasitic inductance. Parasitic inductance causes voltage spikes that can kill your entire controller. I fixed this by running the high-current traces directly over/under each other to minimize loop area thus minimizing parasitic inductance. I also added RC snubbers to the switch nodes to further dampen oscillations and spikes. All of this has allowed it to operate under 12s with no major issues so far.
It would be nice to include few of the development posts. Like a just of what problems you had and how you solved it. So that it’s like the original thread but more efficient.
That’s a very good question. My guess is that they’ll route it out with a normal round bit which will cause the corners to be a little rounded. It’s probably something I should confirm before someone else finds out the hard way. Anyone else have any insight on this?
Laser “cuts” by burning away materials. So the laser would burne the pcb. pcb charres when it burnes and could become conductive in unwanted places.
my guess why they don’t use laser cutters
We were not permitted to cut fiberglass on the lasers at the TechShop because the glass doesn’t cut (although you can etch glass) and the epoxy produces bad fumes.
The through hole for the solder pad under the drv…simply amazing. It would allow some skilled soldering iron changing by those of us without a air station.
Quite interesting.