building the BESC - 100V, 400A motor controller [NOT RECOMMENDED]

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Hey!

Max voltage is going to be 24S or ~100V. Currents up to 350A should be no issue with water cooling but you'll need some high performance thermal interface materials to connect fets to water block. It's not the easiest task but is certainly doable. You probably won't run into pcb overheating issues with battery current up to 300A with standard copper layer thickness. For higher currents you can always use thicker internal layers (3-4 oz). Using a rectangular copper busbar also opens another point of thermal connection to heatsink. It will cool the pcb which will increase the limits but also cool the capacitors.

Vesc firmware is limited for my hardware config. The limiting factor is the maximum current shunts are able to measure which is I think 412A. You can further increase this by choosing shunts with lower resistance (like 150u) and modifying the firmware slightly.

I don't know what kind of axle it was. It was from a qs205 clone from aliexpress I think.

Hope this helps!
 
Hey,

reverse direction is working using ADC settings DutyCycle Reverse Button and servo to GND,
only one problem left, even the brake current and the regen current set to 0A at very low speed motor is
trying to regen causing big vibration what might be the reason for this?
 
Found another HW bug, R73 and C84 designators are swapped, but this is just filtering for the PPM input, not sure if anyone has used it yet.
 
erdogank said:
Hey,

reverse direction is working using ADC settings DutyCycle Reverse Button and servo to GND,
only one problem left, even the brake current and the regen current set to 0A at very low speed motor is
trying to regen causing big vibration what might be the reason for this?

Changing ADC-General - Negative Ramping Time from 0.10s to 3s solve the regen problem now the regen is smooth.
 
The updated files that Galp supplied were very useful. One issue is, at least for now, is these are just gerbers. Users dont have his updated kicad files which are useful for making BOM and position files in the case were you interested in having your boards made by PCBA.

So I'm uploading a zip file that contains kicad files, BOM, part position file, and some instructions for how it was generated.

I have sent these for PCBA to PCBway, and I'll report back if that process goes well. (Believe me, there are LOTS of places it can go wrong).

!!!!!!!!!
EDIT / NOTE FOR THIS POST: THIS FILE SHOULD NOT BE USED. I introduced some problems in the circuit. At present I am running galp's 1.1 and they seem to be working fine. The problems are relatively minor, but I should post an errata. Also, the information here for making centroid files is just fine, but the changes I made in the kicad file should NOT be used
!!!!!!!!!

Please review this post here: https://endless-sphere.com/forums/viewtopic.php?f=2&t=109266&p=1685835#p1685835 which has updated file

Construction items:
------------------------------------------
This board started with Galp's v1.0
Modifications to schematic:
-changed pins of the crystal (to connect circuit to 1 & 3)
-tied pin 2 of crystal to ground
-changed crystal to (ECS-80-18-30B-AGN-TR)
-trace to pin 2 of crystal to ground
-changed footprint of crystal
-removed U7, fixed traces
-minor changes to silk
-added "MANUFACTURER", "PART", "SMD/TH" into symbol editor, populated all those fields
dumped all the parts into single column, cut and pasted into mouser BOM maker
cut and pasted all the part manufacturers from mouser spreadsheet into the symbol editor
edited the SMD/TH column
-the original part for USBLC6-2P6 was wrong
-the foot print for:
C34-C39, C54, C62, C64, C76, C78, C83, C89, C95, C99, C102, C103, C106, C109
should be 0603, changed the part to: 810-C1608X8L0J225K08
-added part numbers for the LEDs

------------------------------
MAKING THE BOM FROM KICAD EESCHEMA
For MacOS,
copy my_BOM2csv.xsl plugin to here:
/Applications/KiCad/kicad.app/Contents/SharedSupport/plugins

Got to Tools->create BOM

Load up your custom script

Be sure to change:

"%O"
to
"%O.csv"

Manually:
-touch up the column headings if needed (in my case there were extras)
-sort on SMD/TH to find rows to remove
-save as excel file
-remove csv old files

total parts: 226
------------------------------
MAKING THE CENTROID FILE FROM PCBNEW:
File --> fabrication outputs --> footprint position file
Select: CSV, millimeters, single file for board
Select: "Include footprints with SMD pad even if not marked Surface Mount"
(gets R31, R32, R33)
Open the resulting file, do these steps manually

-You have to remove some stray parts
remove all refs beginning with J, FED
-Rearrange columns so the fits the headings in the next step:

- add:
"*RefDes<TAB>MidX (mm)<TAB>MidY (mm)<TAB>Package<TAB>Rotation<TAB>Top/Bottom<TAB>Val"
to the top

- save as excel file
- remove csv file

total parts: 226
------------------------------=
PCBway wants all the components could be clustered on to one line

Use bom2grouped_csv from eeschema
Import into excel
Sort on SMD/TH
Remove all non-SMD parts

Total parts: 226
------------------------------
Costs: per board at PCBway is:
$196 for parts (smd only, does not include through-hole parts)
$77 for other costs (shipping, assembly)

EDIT: AGAIN -- DO NOT USE THE KICAD FILES INCLUDED IN THIS ZIP FILE.
Please review this post here: https://endless-sphere.com/forums/viewtopic.php?f=2&t=109266&p=1685835#p1685835 which has updated file
 

Attachments

  • BESC1.0_may2021.zip
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I had a hard time sourcing the gate driver, so I settled for the UCC21521DWR. This seems to be the exact same but with an enable instead of disable pin. I ended up using the inverter, U7, so it is useful to probably keep that footprint on the board, with an option of bypassing it via a solder jumper or zero ohm jumper.
 
owhite said:
The updated files that Galp supplied were very useful. One issue is, at least for now, is these are just gerbers. Users dont have his updated kicad files which are useful for making BOM and position files in the case were you interested in having your boards made by PCBA.

So I'm uploading a zip file that contains kicad files, BOM, part position file, and some instructions for how it was generated.

I have sent these for PCBA to PCBway, and I'll report back if that process goes well. (Believe me, there are LOTS of places it can go wrong).

Hi,
I'm also try to order some boards from jlcpcb have a question regarding BOM and CPL, jlcpcb doesn't identifie all the elements and placement are this files done for different manufacture ? and also you file version is 1.0 it means it uses the older 1.0 schematics there are no fixes from 1.1 ?

I checked with PCBway it's almost double the price for PCB didn't checked the components.

Thanks.
 
So I used the 1.0 schematics for my order because Galp did not publish the kicad files for 1.1. I needed the kicad files to make the files for PCBA.

I think you are asking about how to make the CPL files for jlcpcb, but I'm not sure about your exact question. If you need to make the CPL files for jlcpcb, I can assist if you give me an example.

I would not compare the cost of PCBway to jlcpcb until you get a price quote from both that includes the cost of the components.
 
Would be good if smd components would be on one side, will be cheaper to produce.
I saw on you github page that you had only fet module was it prototype and controling on other board or it was only to show power side of the board.
 
owhite said:
Galp, have you tested 1.1? Just curious if you've built boards from those files.

I downloaded the files from his site, v1.1, and finished assembling and programming them a couple weeks ago. No issues here.

On another note, anyone have extra STM32F405RGT6? Luckily I had a friend send me the two I needed, but another friend is looking for two more. They are out of stock from most of the main distributers, with a lead time of several months. If anyone is able to send me some he would greatly appreciate it. Obviously willing to pay for them and shipping (to US).
 
Thank you, that's very helpful. And I dont have any new STM32F405RGT6s but I do have a few toasted boards. (Catastrophic shorts probably between heat sinks of FETs and ground) -- but they still seem to program and light up the LEDs. I could put the boards in toaster over and yank their CPU if you're interested -- alternatively if you want to recover other parts you could have the boards.
 
I ended up finding some Olimex dev boards for $18 a piece. Unfortunately he ordered them and they shipped already, but thank you for letting me know - I'll keep it in mind.

What encoders are you using with them? I'm planning to use AS5047s. The connection should be the same as any other VESC, right? H1-SCK, H2-MISO, H3-CS?

Ah - I just figured out I have to manually subscribe to threads to receive notifications. Sorry for the slow replies.
 
Hi guys, I am thinking of building this board, but I would like to know some information on battery charging. I can't find anything about anything like the charging mode which uses one phase of the motor as an inductor to increase the voltage of the charger based on the battery (likes some commercial controllers do). Is there already someone working on it or should I start modifying the firmware (and maybe the board) from scratch?
 
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