Smooth eDrive - VESC compatible ESC development

[Addy]

Hello! It's time to share the project I've been working on for several months now. I will post updates here of development progress and test results.

Description

Smooth eDrive is a VESC compatible 12-FET ESC for ebikes. It's designed to be powerful without breaking the bank.

I've been using a VESC V4.12 ESC for my ebike for a year now. It's been a great controller and I'm a big fan of the FOC mode, but it's definitely undersized for an ebike.

I wanted to have a more powerful VESC for my ebike, but when I started this project there weren't many VESC variants available. I designed my own VESC-compatible ESC so that I could have the power and features that I want. If other people are interested in this controller, I will have enough parts to build more units.





PCB Renderings:



Features

• Full FOC support, with current sensors on each phase
• Works with batteries up to 80V. Power stage is rated for 100V
• Highly customizable
• Uses open source VESC firmware
• Uses aluminum extrusion case for good heat dissipation
• MOSFET temperature sensing and protection
• Flexible wiring options:
  • Analog throttle and regen inputs. Also has spare analog input.
  • 12V enable, can be connected to a switch to turn ESC and 12V supply on/off
  • Optional USB connection, for PC configuration and realtime data monitor/logging
  • CAN bus support, multiple VESC controllers can be linked for 2WD setups with traction control
  • Built-in 12V 3A power supply, to run ESC and external 12V accessories.
  • Low power 5V and 3.3V to power hall sensors, throttles, etc
  • Compatible with optional bluetooth module

Future Features

• Field weakening
• Battery temperature monitoring and protection

 

[Addy]

Progress so far:
The PCB layout is complete and some prototype PCBs have been ordered. The aluminum cases have already arrived. Next I will put together a parts order so I can start assembling some prototype controllers once the PCBs have arrived.

 

[Grantmac]

Can you PM me with costs for the initial run?

 

[florkk]

can share how much it will be cost

 

[district9prawn]

Awesome to see more vesc based controllers popping up.

 

[Addy]

I'm almost done putting the BOM together. I would estimate that for the initial run I could sell these controllers for around ~$450 CAD (~335 USD).

 

[Addy]

PCBs arrived today! I think they turned out pretty good.






The PCBs also fit very nicely in the aluminum cases.

My parts order has also arrived, so I'll be able to start assembling a board and doing some testing.

 

[Addy]

Today I installed all the parts needed for the 12V DC/DC converter on a board so I could do some stress testing.


View attachment 1


The DC/DC converter is set up to put out about 13.5V. It's a bit higher than 12V, which helps for running accessories like automotive lights at full brightness. To stress test, I hooked up 2 12V automotive bulbs which drew 2.96A. With this load the output voltage dropped to ~13.25V. After running this for 10 minutes I checked the temperatures with a FLIR camera.





The hottest part was one of the MOSFETs, which reached about 100°C. That's pretty toasty, but all the parts are still within their temperature ratings.

I'm happy with this performance. I wouldn't recommend loading down the 12V supply fully like this for normal use, but it will survive this kind of treatment.

 

[Addy]

After the testing I did in my last post, I started having trouble with the 12V supply. If you try to draw more than ~2.5A, it goes into "hiccup" current limiting mode. I've been doing a lot of troubleshooting to figure out the cause of this. By design, the supply should put out well over 3A before doing any current limiting. I'll continue to debug this issue, but in the meantime the power supply still works well enough to power the ESC.

I just finished getting the first case and heat spreader ready. I've got a template for drilling the holes in the heat spreader and the case. Thanks to the template, the first heat spreader fits pretty much perfectly.


View attachment 1

 

[Amiran]

Hi,
What's the continuation of this story?

 

[Addy]

It's been too long since I posted an update here

I have been busy this summer with trips, family events and other tasks. Some progress has been made with the ESC.

I started my own fork of the VESC firmware, right now the only unique thing is the hardware config files needed for the SmootheDrive. The firmware has been flashed on the ESC and I have been doing some testing. I have a 6374 motor hooked up to the ESC for testing. The motor is coupled to another 6374 motor which is used as a mechanical load. I have some power resistors connected to the load motor so it takes some effort to spin it.

The motor is spinning up properly in sensorless mode. Currently I am checking the switching waveforms and adjusting the deadtime. I had some gate driver chips blow up before. I have new gate drivers to use now, which have built-in interlock logic to prevent shoot-through.

For the next task, my partner and I will be testing the ESC on an ebike. My partner has built his own SmootheDrive, so there are 2 units for testing now. I already have plans to make some changes to the PCB layout and hardware design. After some more testing has been done I will work on revising the PCB.

Here's how the assembled PCB looks:

 

[Amiran]

Thanks for an update.
All the best of luck.

 

[casainho]

I am really happy to see this project. I think VESC is really great, I wish the chinese could make and sell ebike controllers based on VESC hardware... what if they adopt your hardware and then they could sell it for 100 euros??

 

[Grantmac]

I am really happy to see this project. I think VESC is really great, I wish the chinese could make and sell ebike controllers based on VESC hardware... what if they adopt your hardware and then they could sell it for 100 euros??

I'd buy 3.