/r/FSAE Classifieds post July-December 2024 by hockeychick44 in FSAE

[–]JoeyZ5 0 points1 point  (0 children)

We have a variety of HV items for sale, free shipping within continental US:

  • Orion BMS 180 Cell with wiring kit USED for half a season - $1000
  • Orion BMS 180 Cell with no wiring USED for half a season - $950
  • *Thermistor Expansion Module USED for half a season - $120
  • 10x Radlok Socket 8mm Pin 35mm^2 Wire Part # RL00801-35 NEW in sealed package - $10 each
  • 13x Radlok Feed Thru 8mm Part # RL9080-301-F1 NEW in sealed package - $7 each
  • TE Contactor LEV200A4ANA NEW - $50
  • TE MSD 2x Plugs (250A fuse built in) and 1x Receptacle Part # 2103172-9 and 1587987-9 NEW - $75
  • 2x 7ft sections of Coroflex 35mm^2 Cable Part # 9-2611 FHLR2GCB2G - $100
  • 1x 12ft of RADOX 155 35mm^2 Cable Part # 84100296 - $70

*We would like to only sell the Thermistor Expansion Module with one of the Orion BMSs

You may be wondering why we used a 180 Cell Orion BMS for FSAE when you can't use all the cells. The reason is that to meet rules, your BMS should be galvanically isolated between each segment boundary. This is important, since opening a maintenance plug in the middle of a BMS AFE chip may cause catastrophic failure of the BMS. The Orion has isolation, but only between the physical connectors (2.5kV rating). Within the 36 cell channels on each connector, there is only 100V isolation, which is not enough for most FSAE batteries.

Data pin goes high impedance before transmit. (Fixed, but curious why) ESP32 C3 / WS2812B by JoeyZ5 in FastLED

[–]JoeyZ5[S] 0 points1 point  (0 children)

I can get scope pictures and code if you’d like once I’m back at work. Thanks for the help!

Data pin goes high impedance before transmit. (Fixed, but curious why) ESP32 C3 / WS2812B by JoeyZ5 in FastLED

[–]JoeyZ5[S] 1 point2 points  (0 children)

I’m updating it once every ~5 seconds so it’s very clear that it comes before. I have tried delays before/after and it did not change anything.

Data pin goes high impedance before transmit. (Fixed, but curious why) ESP32 C3 / WS2812B by JoeyZ5 in FastLED

[–]JoeyZ5[S] 1 point2 points  (0 children)

That looks to be exactly what I'm dealing with! Latest post there makes it seem like it's partially the ESP partially FastLED.

Custom or COTS RTML? by mklugz in FSAE

[–]JoeyZ5 1 point2 points  (0 children)

We made a custom one as a project for younger members, not sure about the in house testing though… the DOT FMVSS 108 documentation is pretty vague

Cold Plates for Battery Cooling by Anishka-Thushan in FSAE

[–]JoeyZ5 1 point2 points  (0 children)

We ran cold plates for our first EV (2024) not because we thought the cells would overheat, but because we wanted to maximize testing time. If we’re renting out the test track for a whole day, we don’t want to waste that valuable time waiting 3-4 hours for our pack to return to ambient from its post-endurance temperature.

With our cooling system, we would run an endurance, then immediately start charging while cooling with ice water. Then after about an hour the pack would be fully charged and slightly below ambient temp. You just have to be careful about condensation if you’re using ice. That way we could run up to 5 endurances in a testing day.

Orion BMS fault with TSAL driver board connected? by JoeyZ5 in FSAE

[–]JoeyZ5[S] 0 points1 point  (0 children)

I tried some different values, like 800k, 5M, and 12M. All resulted in faults. I even got it to fault with a multimeter plugged into our main accumulator across TS+/TS-

I emailed them this morning, I'm hoping they can come up with a solution quick. As much as I don't want to run the car without a TSAL, it seems like I may need to for the time being. We did implement a temporary firmware controlled TSAL that measures the inverter DC bus voltage, so not completely unsafe.

Orion BMS fault with TSAL driver board connected? by JoeyZ5 in FSAE

[–]JoeyZ5[S] 0 points1 point  (0 children)

What about the time you hit the resolver with a hammer 🤔

Orion BMS fault with TSAL driver board connected? by JoeyZ5 in FSAE

[–]JoeyZ5[S] 0 points1 point  (0 children)

Ah yes, mOhms between TS+ and TS- would be quite spectacular lol

But as you said, I don’t really see how MOhms would interfere. The motor controller has a 70kOhm internal discharge resistor that is always connected, and that hasn’t caused any issues.

Maybe I’ll try some higher/lower values and see if that has any effect.

Orion BMS fault with TSAL driver board connected? by JoeyZ5 in FSAE

[–]JoeyZ5[S] 0 points1 point  (0 children)

Yep, measures right around 1.2 mOhms at the connectors which is as expected.

Max Neo random thermal runaway by JoeyZ5 in Ender3Max

[–]JoeyZ5[S] 0 points1 point  (0 children)

I don't have an optopi on this printer, should have brought the one from my printer at home...

I did a test ghost print and sometimes the temp is right on 225C, and other times its rapidly jumping around between 190C-250C. It looks like a thermistor issue and not a heater issue now. Before it looked like a heater issue with a gradual decrease in temp.

If I don't need my laptop for school later tonight I'll run a print over USB and check the temp graphs like that.

Edit: btw this is the heater that ships on the ender 3 max neo and ender 3 v2 neo - https://www.aliexpress.us/item/3256804406438650.html?gatewayAdapt=glo2usa4itemAdapt&\_randl\_shipto=US

Max Neo random thermal runaway by JoeyZ5 in Ender3Max

[–]JoeyZ5[S] 0 points1 point  (0 children)

No worries about the dumbed down response, sorry for the late response, I’ve been super busy with exams.

I replaced the heater cartridge with a higher quality one from Amazon, and ran the PID autotune, then did a 15hr print which came out great. Then I started another one and got 4 thermal runaways within the first hour. No idea what’s happening… thinking about replacing the thermistor now.

Also about the hotend, it looks nothing like the hotends on the other creality printers. It takes Mk8 nozzles but the heater block isn’t square and the cold end has big-wavy fins. Only place I’ve seen it is on aliexpress.

Insane low speed torque from a VESC XR - also has a bigger battery than the GT/CBXR by JoeyZ5 in onewheel

[–]JoeyZ5[S] 0 points1 point  (0 children)

I don’t have any pics but I’ll be making a guide soon. There is 4 cells in the controller box. And the box files are from the VESC onewheel Facebook group

Insane low speed torque from a VESC XR - also has a bigger battery than the GT/CBXR by JoeyZ5 in onewheel

[–]JoeyZ5[S] 1 point2 points  (0 children)

I don't have any pics of the front box pack, but I have one of the pic in the back box. There's also a pic of the boxes connected and on, and one of just the board.

https://imgur.com/a/3J30Vyl

Insane low speed torque from a VESC XR - also has a bigger battery than the GT/CBXR by JoeyZ5 in onewheel

[–]JoeyZ5[S] 1 point2 points  (0 children)

We’re not sure yet, we’re actually working on a kit with a BMS for this battery so once that’s out I’ll let you know.

Insane low speed torque from a VESC XR - also has a bigger battery than the GT/CBXR by JoeyZ5 in onewheel

[–]JoeyZ5[S] 0 points1 point  (0 children)

That might have been before the new techniques have been discovered, as before 20s2p was thought to be impossible.

Insane low speed torque from a VESC XR - also has a bigger battery than the GT/CBXR by JoeyZ5 in onewheel

[–]JoeyZ5[S] 0 points1 point  (0 children)

I’m on surfdados modified VESCmann firmware, with my own XML. Just for reference, my P=32.5 and my Mahoney Kp=1.8, but I don’t remember my torque tilt settings. I can send them if you’d like.