Unreasonable E-MTB build - Me too, I want to faceplant on dirt at 60km/h (and commute everyday too)

OMGOMGOMG ! Thanks a lot @Riako, I will take a look at those marvels :slight_smile:

Cheers !

Boubak

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Unfortunatly none of the two battery pack will fufill my needs:

  • Overion box is not waterproof
  • Willozboard box can’t go higher than 100A

BUT, the willozboard design really inspired me, especially the fastening system with pp belts : Willozboard battery pack fastening system

And I have my first dilemma, I want to choose which VESC 6 model to buy, and I want a robust one:

VESC6 from Trampa :

  • Pros :

    • the official from Benjamin Vedder can go up to 80A continuous
    • tested and abused by @NoWind, seems to wistand at least 100A continuous under good cooling conditions
  • Cons :

    • no integrated anti-spark switch
    • the most expensive one

Flipsky FSESC 6.6 with aluminium case :

  • Pros :

    • with integrated anti-spark switch
    • seems to be waterproof out of the box
    • affordable
  • Cons :

    • advertised for 60A continuous
    • not sure if it’s quality built
    • currently sold out

Flipsky Dual FSESC6.6 :

  • Pros :

    • dual esc on the same PCB
    • integrated CAN connexion
    • up to 100A continuous per ESC
    • affordable
  • Cons :

    • no anti-spark switch anymore
    • not sure if it’s quality built.

I can’t decide between the three of them. I’m open to any piece of advice/observation and other VESC based ESC I don’t know right now :).

P.S : Can I safely control two anti-spark switch from the same button ? (or maybe there are 200A anti-spark switch?)

Cheers,

Boubak

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Get one of this

If you lucky stewii has two left for you.

Don’t relay on the Flipsky 6.6 anti spark. I can’t proof it with own experience, but I read here that the switch is the only down side of this vesc.

Get one of this

From @Martinsp if i‘m not wrong they work up to 150a

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Yes, try to go with the ESCape, or maybe the new fsesc6.6 without antispark. Put an XT90s or someting like that maybe for your PSA :wink:

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@Andy87 and @Riako :

Thank you both for your advice :slight_smile: .

I think I will try to buy dual ESCape from @stewii, It seems to be very nice, especially with the heatsinked dual enclosure in aluminum.

@Andy87 :

Thanks, I started to get in touch with @Martinsp for his cool anti-spark switch.

@Riako :

PSA :slight_smile: ? Power Switch Alchemy ? Portable Super Anchor ? Peugeot Citroen XD?

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Sorry, to use an XT90S as Power Switch Anti-spark :wink:

sl33py make a good how to if you want more details > https://www.electric-skateboard.builders/t/how-to-anti-spark-xt-90-loop-key/204

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Thank you :slight_smile: I will take a look but I think I prefer an electronic anti-spark switch.

By the way can an XT90 connector sustain a 200A current indefinitely ?

Cheers,

Boubak

I’m pretty sure an xt90 can take up to 90 amps.

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Thanks for the information, so with my goal of oversizing stuff for bullet-proofing my build, it’s maybe not a good idea to have XT90 connector to handle 200A.

Cheers,

Boubak

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which wires you want to use for 200a? If you really think you need to oversize your build you can run only positive wires through one xt90 and only negative wires through one xt90. It would give you 180a in total.

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8 or 6 awg

And I will not use XT90 for the main power wires, but big bullet connectors instead.

Good luck trying to achieve 200A :smiley: I am running ±90A mot/bat battery never reached more than 50A on bat per esc. XT90 is more than enough. I am at the moment running everything via AWG 12 and even MT60 motor phase connectors they get a bit warm after long rides but everything else is not even warming up :slight_smile:

Plus not a single esc on this forum apart maybe arc (haven’t tried or didn’t hear anything about it yet) could handle 100A bat continues without heavy sweating :slight_smile:

Don’t forget your battery wires are not even bigger than 10AWG and internal tabs will not handle more than 100A continues just short burst of high current :slight_smile:

ESK8 Loads are short burst so wires/connectors don’t even feel it :slight_smile: It’s more concerned for like E-Foils where they have constant loads :slight_smile:

So I don’t see the point of over-engineering this stuff :slight_smile: just a waste of money :slight_smile:

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@Kug3lis

Thanks for your message !

I disagree :slight_smile: and I will try to explain my logic :

You don’t take into account my initial constraints, especially one :

  • bullet-proof

From the strict engineering point of view, I have no interest in lowering the modularity of my system by downgrading subcomponents of the power chain to match them with their neighbors. It will just be an pre-optimisation, for gaining what? Small savings and a little bit of weight.

And money was never in the constraints (neither weight by the way).

I will add that 200A continuously is my goal for having a safety margin considering the worst case.

Plus we have two kinds of components :

  • the self-protected *. the others

In the “self-protected” category we have all the bottlenecks , naming the ESCs and the battery pack (according to the fact that I will put a BMS). They will cut before burning.

In the “others” category I have :

  • Motors → APS C8085 : big safety margin
  • anti-spark switch → dual push to start from @Martinsp : 200A continuously 240A in burst
  • Wires and connectors → I want a big safety margin too, because as the two previous from the same category, they will not protect themselves.

Doing that will insure me that I don’t add point of failures and that if someday I change my ESCs for something that can withstand 200A continuously, I will not have to change other components. So it keeps my build modular.

And I prefer having just my ESCs sweating instead of everything in the worst case.

I want to build a 12s2p pack from 4 Compact 6200mAh 6s 40c Lipo Pack from Zippy, that makes a 12400mAh 40C pack : even if considering that it’s bullshit and that I must only take account of 20C for safety reasons, that means drawing 248A max continuously. Plus they will be managed by the BMS.

And I have turnigy lipos from an other project that have 8AWG wires, so 10AWG is not the max at all on commercial packs.

I will add that you’re giving me your ride values, but it’s irrelevant :slight_smile: : we probably don’t ride the same way, not with the same hills, not with the same external temperatures, so I’m pretty sure we have different needs(commuting in Paris is just a part of the story). And I know myself and I am pretty demanding on the gear I use when doing board sports and motor sports.

And I know that It will be more difficult to build ( especially the “heatsinking the BMS” part, I fear)

But maybe my logic is faulted somewhere and I will be happy to now before doing something crappy. :smile:

And now you know my reasons and that it’s not just brainlessness.

Cheers,

Boubak

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Well, I am from London, I ride really aggressively and high speeds my average speed on a commute to work is probably will be double than yours :slight_smile:

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These are just like highest values I can find consumed from the battery and etc :slight_smile:

But yeah I was the same thinking like adding copper 2cm bus bars and etc on the build I am currently riding and was thinking that I will need attach everything directly to it and other things after riding for more than 5k miles I just swapped to MT60 connectors still use XT90 on focboxes but if I build next one I will just go with XT60

By the way, my both motor and bat are ±90A never seen it on any of logs :slight_smile:

But yeah try it out after some time you will come to realise the same as me :smiley: I will be able to tell more after I switch my motors to 80100 in upcoming weeks :slight_smile: Probably MT60 will heat up quite a bit but still I don’t expect more power consumption than now as my board will not change much its weight or resistance and etc probably will even drop as new gear drive is more efficient than the current one :slight_smile:

But yeah I am not riding much off road yet so maybe I will see more current spikes and etc when I will enter mud roads :smiley:

P.S. Even if you manage to consume 200A you will need to heat sink the shit out of that anti spark switch :slight_smile: and other components in power delivery side especially BMS if you will be able to find a good BMS with good mosfets and etc :slight_smile:

But yeah keep working project looks good :slight_smile:

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how the f… you stay stable at 80km/h on a trampa? 50-60km/h ok that´s still fine for me, but 80 :sunglasses: it´s with your own dampas or you ride the white ones :sweat_smile:

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blue ones :slight_smile: I havent even had a single wobble with them :slight_smile: My dampas are for like up to 40-50kmh max if your legs are strong. Also that was on one big downhill i can’t reach more than 68km/h on flat surface :slight_smile:

ok that´s how i expacted it to be :sweat_smile: I run yellow front and red back and the wobbles start at 50km/h round about. should be like this.

Damn @Kug3lis you ride too fast, hopefully without loose magnets :stuck_out_tongue_winking_eye:

I had yellow dampas but after about 1000km they got weaker and speed wobble started at about 40km/h.

@boubak sounds like a fun build, especially with 80mm motors!

Just a few thoughts, if you really reach 200A from battery I send you a gold medal. I think maybe you could have 150A spikes depending on your settings but not continious. I use 6374 motors (65A motor max / 50A batt max) and normally I reach together 100-130A motor max and 50-70A batt max each ride. Only once I reached 97A batt max but only because I wanted to reach it. I did hardcore 100% throttle accelerations from standstill.

I have the Vesc6 inside an ABS enclosure without cooling and quite rainproof. It’s getting warm inside but not hot. Even in sizzling summer the temperature of the vescs never exceed 50-60° C.

BTW my enclosures are fine with rain but I found out that my remote didn’t like rain and my voltage meter broke. Easy solution for remote: put hand with remote inside a plastic bag :laughing:

I bolted my pelicase with 4 screws to the deck each 4cm away from center to keep the flex as @Andy87 explained. Best would be more narrow or only in the middle but I’m not sure stability wise. It’s important to use some rubber spacers between deck and enclosure for flexing. My first enclosure was steel without rubber spacers and it bent. Now I can bottom out the deck without problems.

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Still with loose magnets :smiley: But I am with blue dampa so no wories about wobbbles :slight_smile:

I wonder if the motor can lock up with loose magnets, i would be afraid