Serious FOCer (84V VESC 6 based controller)

[cheapcookie]

shaman do you have a brand ? This is a commercial venture correct ?

 

[shaman]

Yes I'll be looking to sell this commercially. I do have a domain and business email setup now but I wouldn't say I have a "brand" built.

 

[john61ct]

Can this design be adapted to 48-54V range packs, for very low speed but **very** high torque output?

What would be the biggest phase amps output range in that scenario?

Biggest battery amps draw?

Context: https://endless-sphere.com/forums/viewtopic.php?f=14&t=102203&p=1495384#p1495384

 

[shaman]

@john61ct my first post answers your voltage question.

Features:

• 15V to 84V operation

Max motor phase amps will hopefully be around 150Arms peak and 75Arms continuous for the Serious FOCer. Max battery amps would be similar in the same regard. Amps will determine the torque output of the motor. You're motor would hopefully have a torque constant, a value from its datasheet, that allows you to calculate the amount of torque produced based on how many amps are flowing through it. I don't know what you consider "high" torque. Torque requirements for your particular situation will become a classic statics and dynamics problem. You have weight, incline/decline grade, gear ratio, speed, air resistance, wheel diameter, ect to account for. There are ebike calculators out there that could help with this.

 

[john61ct]

OK thanks.

That whole Features list is blanked out in Tapatalk, but launch in browser, renders fine

That is double the Phaserunner ampacity, so hopefully enough

 

[shaman]

That is double the Phaserunner ampacity, so hopefully enough

Yeah thanks to using TO-247s. The estimations I'm giving are what I'm hoping for. Empirical testing will reveal what they actually are when I make prototypes.

 

[cheapcookie]

Do you plan on having stock around 2020? Haven't looked much at the github, is there beta test ready stuff?

 

[shaman]

Hopefully I have these to market at the end of fourth quarter this year. Maybe just in time to snag the holiday season!

So far I've only use my GitHub repository for my open source hardware stuff like the cheap focer. most likely my GitHub will only have the firmware and schematics for my commercial products.

There aren't any beta units available yet. I'm still moving through this design review with @Marcos. I have to finish up that design from that render you found and then see what Marcos has to say about it. Hopefully this will be the one. After the design review is completed, I'll create a prototype for my own analysis. I'll take it to the lab and do some basic tests. after I get some good data and have made any necessary changes to the design, I'll look at creating some beta units. Beta testing will be no joke this time around. Serious contenders only.

 

[Amiran]

Shaman,

Would like your thoughts on testing your foc unit with hub motor QS 205 3.5T in 20 inch moto wheel with 120A max battery current peaks and 60-80a continuous.

If cheapo old tech 24F controller survived this, your s should do with 12Fets? No?

I am located in UK and happy to take a part.

Thanks

 

[shaman]

This could be in the territory of this TO-247 controller but you will need some really good cooling. What voltage are you running?

 

[Amiran]

Hi Shaman,
Running now 11s but looking to build 13s soon.

I am sorry to ask I do not know vescs very well yet, will the controller turn the power down if it overheats?

What part will get damaged for overheat due to over current?

Would it be to mosfets?

What I'm trying to say here would it be possible to have quick soldering fix, upsize the cooling and get back on the road?

Thanks

 

[shaman]

Yes my controller will do thermal throttling and even thermal shutdown based on the measured temperature of the mosfet case. These thermal thresholds can be set by the user but I would recommend using the default values.

Yes the components most likely to take damage from over current or over temperature would be the mosfets. Yes I intentionally designed with through-hole package mosfets to make repair easier among other benefits such as easier heat sinking

 

[Amiran]

Sounds right and practical too.
Easy repairs are good thing when you are experimenting.
Let me know if we can arrange something.
Thanks.

 

[shaman]

UPDATE

Design review was concluded. Thank you very much @marcos for your design review services! I've learned a great amount from that experience.

I've ordered the boards and BOM components to make an initial prototype. The holiday in China slowed down the orders a bit but all should arrive next week.

I'll be assembling the prototype and analyzing it in the lab like I did with my Cheap FOCer. Once issues/changes have been identified, I'll make the revisions to the design and place orders for materials for the beta units.

 

[shaman]

I'll have the prototyping materials delivered by the end of today. I'm borrowing a reflow oven from a friend for the weekend. Gunna set up the development environment for the VESC firmware/software tomorrow.

 

[InterestedinEVs]

Excited to see how it turns out!

 

[shaman]

Alright. Got it soldered up. Had to fix a couple of stupid mistakes (wrong pinout for crystal, no power to the IMU, ect). I haven’t powered it up yet. I think I’ll leave that for this week when I can get to the lab with a current limiting power supply. Better play it safe.

Until then I’m working on the code. It’s been a copy/paste operation so far with what Mr. Vedder has already written.

Also the connector panel is a flimsy piece of crap. Gunna get rid of that nonsense and put horizontal JST connectors in a over/under configuration on the edge of the control board. This will raise the overall height by about 4mm but I think it’s worth it.

 

[InterestedinEVs]

I was reading along and looking at pictures and thought, "Dang, that end board looks sketchy." Great thought, but I agree, probably better to move away from it unless you could make some sort of bracket to screw it to the other board.

 

[shaman]

Ok. This should do better for connectors in the beta units.

 

[john61ct]

A single block however many pins needed, custom pigtail pinout spec'd for common connectors, maybe the "adapter" sold as an option in various lengths.

 

[shaman]

@john61ct I like the adapter idea for the ebike crowd. Might be tricky to figure out how to work that in...
Maybe simply JST to "insert common ebike connector here" adapter pigtails?

 

[john61ct]

They aren't robust enough physically IMO.

The ones that are similar to what used to be used for robust "ribbon cables" on PC boards internally,

probably designed for 6-8A rather than JST's what, 3A?

Something where the crimping doesn't look for a $50 tool

 

[fechter]

Ok. This should do better for connectors in the beta units.

That looks pretty good to me. Much better than the separate end board.

 

[InterestedinEVs]

Yep, I like it.

 

[shaman]

Thanks everyone! I'm still open to ideas on how to have easily interchangeable connectors. That was part of the logic in having the separate connector panel as I could design different panels for different connector types/configurations and not have to alter the design of the control board.