Serious FOCer (84V VESC 6 based controller)

Electric Motors and Controllers
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qwerkus   1 kW

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Re: Serious FOCer (84V VESC 6 based controller)

Post by qwerkus » Aug 07 2019 1:20am

shaman wrote:
Aug 06 2019 5:13pm
rBVaGFZ4vnyAC5PNAAJ5ck6f2X8987.jpg

One thing that may help with the MOSFET mounting issue is using these split style extruded enclosures. It would allow better access for assembling the unit. They only thing is that these typically don't have a lot of fins or seem to display good heat sinking features. Not sure if thats a valid concern or not. Maybe potting the controller with thermally conductive compound may help compensate. Probably expensive though.
Yeah; szomk (how to do pronounce the name?!?) is rather expensive. Also, this split type is tricky to seal.

1N4001   100 W

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Re: Serious FOCer (84V VESC 6 based controller)

Post by 1N4001 » Aug 07 2019 1:47am

shaman wrote:
Aug 06 2019 11:38am
Max is 84V(20s). That will be verified in testing. I'm assuming batteries will sag down a bit during high current loads. Calculating power at 75V loosely accounts for this.
I would seriously suggest increasing that to at least 95V, if not 100V. Even with your input caps, inductance in the battery wiring will induce voltage spikes far in excess of 84V when quickly reducing load.

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Re: Serious FOCer (84V VESC 6 based controller)

Post by shaman » Aug 07 2019 5:14am

@1N4001

I'm talking about the voltage for calculating power transferred to the motor. That's not going to be calculated with the voltage of any spikes or transients.

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Re: Serious FOCer (84V VESC 6 based controller)

Post by shaman » Aug 07 2019 5:18am

qwerkus wrote:
Aug 07 2019 1:20am
szomk (how to do pronounce the name?!?) is rather expensive
Actually they're one of the cheaper manufacturers of enclosures I've found that has reasonable MOQs for my situation. Did you check anything other than AliExpress? I bet getting a qoute from them directly on a an order of 100pcs or more yields something like $3 per unit or better.

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Re: Serious FOCer (84V VESC 6 based controller)

Post by peters » Aug 07 2019 7:36am

Will you publish your schematics? I'm wondering how you connect your gate driver and power supplies.

shaman   1 kW

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Re: Serious FOCer (84V VESC 6 based controller)

Post by shaman » Aug 07 2019 8:00am

peters wrote:
Aug 07 2019 7:36am
Will you publish your schematics? I'm wondering how you connect your gate driver and power supplies.
Yes. Though I'm not sure schematics alone will tell you how exactly I'm connecting things. What particular curiosities do you have surrounding the gate driver and power supply?
enclosure concept.JPG
enclosure concept.JPG (52.79 KiB) Viewed 2821 times
Still brainstorming the enclosure here. I've thought about this approach in the past but put it aside due to costs. It uses the heat sink plate and then has a plastic (ABS or Nylon) enclosure that slides/fits over it. It can have a lid if needed and also the connector panel. The problem is finding how to produce the plastic part at low quantity with decent costs. Injection molding requires a high MOQ just like custom extrusions. I've looked at one 3D printing service and the cost was something like $8 per unit fro ABS plastic at an order of 100. That's too high in my opinion but maybe other companies are cheaper.

Any ideas for this?

EDIT: I reoriented the model and couple of other things to make it more 3D printer friendly. Now quotes are between $3USD and $4USD for 100pcs which is more acceptable.
Last edited by shaman on Aug 07 2019 8:49am, edited 1 time in total.

nieles   10 kW

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Re: Serious FOCer (84V VESC 6 based controller)

Post by nieles » Aug 07 2019 8:21am

i think he would like to know you you are going to connect the two pcb? the brain and power pcb.
atleast that is what i would like to know. (from the schematics)

how will you guarantee the solderjoint is made on both the top and bottom pcb? are all solder joints reachable from both top and bottom side of the stack? (so you can individually solder the top pcb from top side and vice versa)

also are you worried about solder wicking between the two pcb's? i have pondered the idea of making multi layer board from a stack of multiple pcb for the last few years, but never actually tried it.
mostly because i am afraid warping forces and other unforeseen things will ruin the controllers in the long run. or solder wicking between the two pcb's.

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Re: Serious FOCer (84V VESC 6 based controller)

Post by shaman » Aug 07 2019 8:36am

@nieles I guess I'll be the guinea pig. I'll keep yall updated if I find any problems making a PCB sandwich.

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Re: Serious FOCer (84V VESC 6 based controller)

Post by peters » Aug 07 2019 10:38am

That's also interesting, but I just looked at the datasheet of DRV8353RS and interested in how you apply it. It requires max. 75V on the VM input, but your battery max is 84V, has an internal DC/DC converter that you probably use to supply the uC, but there is no inductor on your 3D view. Things like that.

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Re: Serious FOCer (84V VESC 6 based controller)

Post by shaman » Aug 07 2019 10:58am

I'm using the DRV's built in buck converter to create 15V from Vbatt. That 15V is then powering VM. The inductor isn't in the model because KiCAD doesn't have a native 3D model for the footprint.

Right now I'm trying to tackle design challenges...not perfecting a 3D render. The renders so far are just for general concept. I'll add missing models toward the end of the development. It's just a cosmetic issue.

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Re: Serious FOCer (84V VESC 6 based controller)

Post by qwerkus » Aug 14 2019 12:06pm

Any update on the ETA of an alpha version of the little focer or whatever will be its name ? I'm considering getting a few lishui controllers to experiment with stm32 platform, but I'd really rather invest that money in a few populated boards of your making :)

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Re: Serious FOCer (84V VESC 6 based controller)

Post by shaman » Aug 14 2019 1:29pm

@qwerkus I'm hoping to have beta units ready in September. The initial prototype(s) will be for my own testing. I'll be doing analysis in the lab just like with the Cheap FOCer. Then after this analysis and any adjustments to the design are made, I'll start looking for beta testers.

I'll need serious beta testers this time. There will be some high expectations from me for the beta testers. However in return for the trouble I'm probably going to provide the beta units at no cost to the tester.

qwerkus   1 kW

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Re: Serious FOCer (84V VESC 6 based controller)

Post by qwerkus » Aug 14 2019 2:07pm

shaman wrote:
Aug 14 2019 1:29pm
@qwerkus I'm hoping to have beta units ready in September. The initial prototype(s) will be for my own testing. I'll be doing analysis in the lab just like with the Cheap FOCer. Then after this analysis and any adjustments to the design are made, I'll start looking for beta testers.

I'll need serious beta testers this time. There will be some high expectations from me for the beta testers. However in return for the trouble I'm probably going to provide the beta units at no cost to the tester.
Ok sounds doable. I don't have the equipment for hardware analysis, but I'm interested into working on the firmware asap. So if there are still design flaws, it doesn't really matter.

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Re: Serious FOCer (84V VESC 6 based controller)

Post by shaman » Aug 14 2019 3:02pm

Cool. Really what I'm looking for is field testing in application. The firmware won't need that much modification over the original VESC firmware to be compatible with my hardware. It's just minor tweaks to be compatible with the particular DRV I'm using. Anything else you want to do to the firmware on your own is fair game.

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Re: Serious FOCer (84V VESC 6 based controller)

Post by qwerkus » Aug 15 2019 10:15am

shaman wrote:
Aug 14 2019 3:02pm
Cool. Really what I'm looking for is field testing in application. The firmware won't need that much modification over the original VESC firmware to be compatible with my hardware. It's just minor tweaks to be compatible with the particular DRV I'm using. Anything else you want to do to the firmware on your own is fair game.
I'm not talking about compatibility with your hardware, but with standard ebike systems. What good would be a controller if we can't plug it to existing sensors / displays ? This might be irrelevant in NA where you can just plug in a throttle, but here in Europe, it's crucial, since throttle only bikes are illegal (you have to register it as a motorcycle). Currently investigating VESC code, and I see no easy way to implement a torque sensor and basic libraries for standard displays. And then there is sooooo much we just don't need for ebikes. I'm not sure I'm going to use the VESC as base; maybe the OS KT firmware is much closer to what we need. IN any case: much work, hence: the sooner I start the better the results!

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Re: Serious FOCer (84V VESC 6 based controller)

Post by shaman » Aug 15 2019 12:21pm

Ah yes I see what you mean now. Yeah the VESC stuff doesn't nativity support some of the common ebike stuff like PAS/PEDELEC, displays, ect like you were saying. I asked Benjamin if he planned to support this stuff but he doesn't seem interested.

The hardware is the there though. Display is probably just UART and code needs to be developed. there are also unused I/O pins on the STM32 that can be put to use.

I'm hoping that these standard ebike features can be integrated into my controller in the future. Maybe even do a pull request for the VESC Tool and firmware that will formally add support for all for all of this. I'll take all the help I can get in that regard!

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Re: Serious FOCer (84V VESC 6 based controller)

Post by nieles » Aug 15 2019 1:21pm

qwerkus wrote:
Aug 15 2019 10:15am
shaman wrote:
Aug 14 2019 3:02pm
Cool. Really what I'm looking for is field testing in application. The firmware won't need that much modification over the original VESC firmware to be compatible with my hardware. It's just minor tweaks to be compatible with the particular DRV I'm using. Anything else you want to do to the firmware on your own is fair game.
I'm not talking about compatibility with your hardware, but with standard ebike systems. What good would be a controller if we can't plug it to existing sensors / displays ? This might be irrelevant in NA where you can just plug in a throttle, but here in Europe, it's crucial, since throttle only bikes are illegal (you have to register it as a motorcycle). Currently investigating VESC code, and I see no easy way to implement a torque sensor and basic libraries for standard displays. And then there is sooooo much we just don't need for ebikes. I'm not sure I'm going to use the VESC as base; maybe the OS KT firmware is much closer to what we need. IN any case: much work, hence: the sooner I start the better the results!
This shouldn't be too hard to add to the vesc. If I remember correctly Benjamin has some examples available how to make a custom application with his code at the base.
You will have to make some code modules to read out the sensor (pas/torque) and pass that information to the core vesc modules.

An other way to do it would be to make a "add-on" board. That reads the pas and torque sensors and translates this to canbus data. Then you configure the vesc as a "slave" canbus device.

Support for kt-display shouldn't be that hard to implement either. You will need make a code module that's running in the slow loop of the controller and spits out the correct data packages on a user.

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Re: Serious FOCer (84V VESC 6 based controller)

Post by shaman » Aug 15 2019 2:58pm

The modular nature of the existing code does allow for easy integration of new code. It wouldn't be hard for someone with embedded experience to do all this. I'm pretty rusty at it but I can still modify existing existing code to do my bidding.

I would attempt for the non-hardware solutions that wouldn't require add-on boards and such. There's already code for exporting display information. It gets transmitted through UART and then to whatever you want (like a BLE module).This is how the VESC App receives and displays data from your controller.

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Re: Serious FOCer (84V VESC 6 based controller)

Post by BenMoore » Aug 15 2019 8:15pm

Excited about all this! I've been very impressed with the capabilities of the VESC but have been waiting on a high voltage version before building my next ebike and the Little FOCer would be just the ticket. Not concerned with enclosure issues personally as I will have my own custom version.
All power to this project!
eBike 1: Crystalyte dual-wind 408/4012 in 20" wheel, 72V LiPo, 20A controller
eBike 2: Avanti Electra (axial flux motor) overvolted - too noisy!
eBike 3: Bafang BPM, Modded ecrazyman controller 50A
eBike 4: 2kW RC motor belt drive with wye/delta switching? - under construction...

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Re: Serious FOCer (84V VESC 6 based controller)

Post by shaman » Aug 15 2019 8:38pm

Thanks @BenMoore! I'm working hard on this!

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Re: Serious FOCer (84V VESC 6 based controller)

Post by drdrs » Aug 15 2019 10:59pm

Thanks for all the work you are putting into this. It looks very promising.

I'm very interested in helping out with the Little FOCer beta testing. I've got a 10 Hz datalogging dashboard on my bike for my ASI 2000 and it should be straightforward to configure it to pull road data from this controller.

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Re: Serious FOCer (84V VESC 6 based controller)

Post by shaman » Aug 16 2019 7:21am

@drdrs

Sounds good! There are also different ways of monitoring and data logging VESC based controllers on your phone through Bluetooth. What is your battery voltage? I have a preference for those running 13s to 20s.

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Re: Serious FOCer (84V VESC 6 based controller)

Post by drdrs » Aug 16 2019 12:31pm

I run a 14s5p LG HG2 battery with a 150 amp BMS.

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Re: Serious FOCer (84V VESC 6 based controller)

Post by cheapcookie » Sep 06 2019 7:36pm

Hey, I am interested in a few of these puppies, what's the state of the project ?

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Re: Serious FOCer (84V VESC 6 based controller)

Post by cheapcookie » Sep 06 2019 7:52pm

cheapcookie wrote:
Sep 06 2019 7:36pm
Hey, I am interested in a few of these puppies, what's the state of the project ?
Image

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