eATB Build: my pursuit for electric freestyle!

LMAO!! So after decideding YES to the beasty 6s batteries I cannot post them to Oz from the EU warehouse! :rage:

The closest match are these :cry:

Hi ESK8ers!

My eMTB build should start this weekend - but in the meantime I thought I’d share some recent antics!

I took a lunchtime cruise on my esk8 this week and decided to check out the BMX track at the top of thread to see if anyone was riding but it was completely dead. As I was there I decided it might be fun to see if my esk8 could make it round the intermediate track. I didn’t honestly expect it could work especially with 83mm road wheels and a single motor but it was actually pretty good fun! Not recommend though and I could easily have destroyed my board / myself, but hey I was curious!!! :smiling_imp: :laughing:

You’ll be pleased to know I filmed it! I only had an iPhone (as I wasn’t planning on doing this!) so quality is dreadful. I do manage to hold it away from the ground as the videos progress! Anyways, enjoy my madness.

Intro and 1st run:

2nd run:

3rd run:

4th run:

The journey back to my office - this has an unexpected ending!! :sweat_smile:

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Time to get the Trampa up in Dirt Bro :sunglasses:

For sure brother! My last parts are at the DHL depot waiting for me to go get them tomorrow morning and then the build starts! I’ll be sure to document the process and share with you guys. CANNOT WAIT for the first air over a kicker! :grin:

Thinking of an 8S dual motor HW Max6 build… really though about the “NoHill” thing how serious are you? I have a 8-12% grade on two 1/8th mile hills on the way to work… this really is both for fun and my commuting vehicle.

So I finally got all my parts together and found some time to make the wiring harness and spun up a bench test…

HOLY FUCK!! This thing is a BEAST!!! :astonished: :grin: :imp:

Cannot wait to test her out in the morning…with A LOT of pads!! :wink:

Still a bit of work to go and I’ll put up proper update here soon…

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Ok…so I went for a spin round the block, and it was beautiful, good acceleration, 50km top end and a super smooth carvey ride. It definitely had the spongey soft snowboard feel.

This has abruptly come to an end now as I’ve fried my FOCBOXs – see thread here.

I’m not gonna dwell on that for a moment though as I’m actually now questioning if FBs are right for what I want. I’ll still try to get them fixed, but in the meantime I thought I’d consider my options. It could be that I hadn’t set them up too well – mostly basic settings but with the cut-off determined and the motor max set to 80 – I was also running them in BLDC as my motors are sensorless.

My current dual set up consists of: Motors: SK3 6374 168kv Battery: 12s2p Lipo ESCs: FOCBOX Drive Train: ETOXX Dual Direct Drive Board: Trampa Holypro My weight: 85kg

Questions:

  • With this set up is it possible to get more of a grunty feeling? One where it tries the pull from under my feet – if you know what I mean?
  • Can I get this feeling from a FOCBOX? I’m kinda thinking I may have made the wrong decision as I’m trying to change the characteristics that the product was designed for into something else, as it’s surely they’re designed to provide a smooth predictable ride? What I want is something that has massive torque and scares the shit out of me when I pull the trigger! It needs to be able to go from standstill immediately and not gradually. I currently get some cogging unless I shift my weight forward and gently ease into the acceleration, but then it’s quick.

Would I be better at this point thinking maybe going for some ROXXYs, FVT Sleeping Lion or the Max6 (obviously I’d need new batteries for Max6)? Or do I just get my FBs fixed and persevere with them? Don’t get me wronf the FBs felt bloody beautiful but exactly like my esk8 and I was hoping for more of a dirtbike feel.

Any advice gratefully received as I know plenty of people (@Duffman, @Whitepony, @Kaly, @squad, @nowind, @laurnts, @onloop, @Mobutusan) have experimented in this space and grateful for your wisdom.

Thanks,

Dan

The force is strong in this one…

Sounds like you already know what you need to do. Going max5/6 you need different batteries and final drive ratio so i’d go the 12s route… I’d be like Jenso and go the roxxy with the shock proofing he did and also some cap banks… I’ve added extra cap banks to my build…

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Thanks @Cobber - I think you’re right, need to get down the ESC route. Anybody here wanna buy a couple of fried FOCBOXs :smile:

@nowind Any ROXXY advice you can give? Would you recommend this over Max6? Gotta say, I would like to still have the higher top speed of 12s dropping down to 8s would be a killer but I could deal with it if the torque gains outweighed it. And I’m super keen for wheelies!!

Man I like your spirit Get the FVT and install the new firmware It will definitely get you where you want to be.

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Thanks @Kaly! You talking about this badboy right?

and this firmware:

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Yeah That is a killer combo

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@DanSkates

I may very well be putting my Roxxys up for sale here soon if you’re interested. They’ve already been upgraded with cap banks too. The brakes are very touchy tho. Only have about 7 miles on them so far. Going to give them a couple more tries and see if I can get the hang of it, but there’s some big hills here and I rely on the brakes a great deal.

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Thanks @benjammin for the potential offer - keep me posted. I gotta say though I was tempted by the FVTs a while back too but chickened out so may just bite the bullet with them this time - especially as I could get 2 posted for less than $200 (AUD).

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Roxxys are powerfull but at the same time hard to controll, brake is really hard to control ! I got a pair of this MAytech Esc´s, flashed with other SW… never get on with it… maybe the FVT are better Max6 is still my worie free favorite, but of course with Topspeed Issues (-; 8S Actually are preparing one of my Roxxy Mtb with Vesc6…

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Ah hell yeah – can’t wait to see you ride a VESC6 monster!

I’m thinking the FVT have gotta be worth a go and @Kaly rates them so gotta be good! :muscle:

And…if I screw that up then I’ll go Max6!!

Aw man, i know that feel, i’ve fried my vescs after a month of riding then switched to FVT120a. They have some quality issues, but are very powerful, and with some tuning and extra caps i like them so far.

The key is to trim brakes to 70-80%, trim throttle to 95%, and use some expo on the throttle (i use x^1.5).

Haven’t tried alternative firmware, i asked for default firmware but FVT guy didn’t give the FW to me :frowning: So i guess i’m not gonna experiment.

Hi, so how do you trim brakes seperately? What remote do you use? I havent heard it is possible to trim these values in esc software (unless it would be vesc)… interested to hear.the story, im using mini remote and only whole signal - gas / brake can be trimmed.

I assume u might be.using gt2b? I know it has more knobs but still not sure about signal trimming on both ends, if u do it.in.hardware with electronics, please give some tips.as this.would be very useful

I’m using my own controller/receiver on arduino. I’ve never used gt2b, judging by the pictures it has 2 knobs for trimming. So first you do throttle calibration on the esc with full range signal, then you trim signal on your controller. To calibrate esc (same for 6s and HV versions):

Hey Dan,

according to your other thread you killed the CAN transceiver because the power connection of one FOCBOX was interrupted:

You should solder the power wires of the FOCBOXes directly together to the power wires ( Y Y ) so that they behave as if they were one controller. The servo input is a bit more tolerant to these faults but this would be the proper soluton. If you later feel like you would like to have traction control, you can solder new CAN transceivers and connect over can again.

What are your current limit settings? I started with 60A which gives good power but a quite smooth startup. I increased bit by bit and now I’m riding 100A motor/battery which gives the desired ‘grunty feeling’ … :wink:

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