You can order 4 if you don’t need the fifth
I’d probably go in for #5. Do you know the cost?
I don’t think you can with JLCPCB. Quanltities are 5 or 2.
You used to be able to order 3 or 4 through a trick with the website (not a hack, they would honor the order and build it) but they have now changed it and you can now directly order
- a multiple of 5
or - 2, 3, or 4
You cannot order six or seven.
… or at least that was the case last time I ordered a couple weeks ago.
And how do you achieve this trick?
Oh, I just checked and it looks like they changed it again, just in the last couple weeks.
I didn’t go all the way through the ordering process, but select 5 in the wizard, then go all the way until you added it to the cart and need to pay, and edit the PCBA quantity in the cart to 4 or 3. Does that still work?
I’m with you on that…
The idea would be to buy more than 5 pieces to get the cost down. Just the pcb at jlcpcb is around 29$ at 5 and goes down to ~19$ at 50. This is still without tax (~10%) and fets caps (~1$ each)
$29 each with most components populated? I’d go for a couple of those if it helps, but it looks like we’re on opposite sides of the world. I’m in California.
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Hey there - I am currently designing my own ESC and let myself be inspired heavily from FOC King, VESC 6 MKV as well CheapFoccer.
I noticed that my main motivation is to create a durable device, which at the same time should be cheap. My main target is ebikes - mainly saving old ebikes with broken sensors, controllers or displays.
As far as I see it, the FOC_KING misses switchable phase filters as well as switchable current filters. Also looking through the current published kicad design files, I am not very impressed by some manufacturing parameters, e.g. there is many places with smaller-than-possible clearance as well as smaller-than-possible traces (6 mil - JLC is able to do that, but 8-10 mil is a reasonable minimum when there is space). I also see no real advantage of a custom-made gate drive, when DRV8320RS is cheaply available and should provide better performance (as well as adjustable gate current for easy fine tuning).
Anyway, while designing my own I noticed that maybe I do actually want to use FOC_KING as base and just add some small adjustments.
A few questions:
One to the crowd: Is there any FOC_KING that failed during operation? What was the failure?
The gate resistors in the design are pretty big - are they neccessary like this, did anybody scope the fets rise and fall times?
In my design, I would have decided for a single TO-247 (like the IRF100P219AKMA1) and maybe add dual footprint with TO220 for a small version - for ebike usage, 30A current with 70A max for a minute is actually enough for the bigger ones, the smaller ones are fine with 35A peak phase current as they overheat quickly otherwise.
Unrelated question: Did anyone play with using phase resistance to roughly estimate motor temperature to avoid overheating? Phase resistance calculation should be easily possible during operation, but it might be inaccurate or having drift effects - there is no good calibration point as it is not guaranteed to have a cold-start…
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>> I am currently designing my own ESC
Do you plan on making your design open-source as well?
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i publish almost every piece of hardware or software i write m NerdyProjects is my GitHub name (i cannot post links yet)
There is no esc yet 
I will also create patches for vesc to handle 1 phase PAS as well as german regulations and maybe some display protocols. Afaik there is no easy readymade ebike vesc fork yet.
Still, hw is my main concern. I could go with makerbase 75200 alu, but somehow I don’t trust their quality enough to justify the price and size., esp. when it needs another waterproofing case as well.
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The advatage is higher voltage . Also i am sure he checked the rise and fall times of the fets
The prices are with the bmi270 presoldered?
No bmi270 available on jlcpcb right now, i could solder them by hand if someone wants it.
I just ordered a bunch of boards at jlcpcb
Are you interested in parting with any of them?
Currently all units I’ve ordered have been reserved. If all goes well I will do a new batch in the summer. How many are you looking for?
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I’d probably take 2.
Just the boards or fully assembled?