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Harbinger | 1:5 chain drive | vesc 6 | sk3 192kv | 9" mud plugger

So this is just another basic vesc 6, chain drive emtb. for those of you who have seen my thread on my MUD MONSTER know that it is riddled with design flaws and poor execution.
the thread- MUD MONSTER, Scrub mountain board | vesc 6 mkIII | 1:7.5 two stage chain drive
don’t get me wrong MUD MONSTER kicks some serious ass, but after upping the motor amps it really put the drive train to it’s limit. so from the ashes/ spare parts arose Harbinger a hopefully reliable mtb to bring good times and good vibes. anyway to the build :stuck_out_tongue:

i had a spare trampa 16ply deck lying around and some over parts to build off.


so i started by drilling holes in each of the sprockets to mount them.
then centre drilled some 12mm en8 steel so i could centre a hole saw on the sprocket

and then set up a pretty janky setup to dill the centre

it also saved a bunch of weight

milled some standoffs to mount the sprockets

i drilled some 8 tooth sprockets and grinded down some cap head m4 screws to use on them

got everything loctited in place

and here are some crap pics, i’ll take some nicer pics soon after a test ride

i took the bindings and vescs off MUD MONSTER while i work on it’s big brother ‘Iron Giant’
i’m running sk3 192kv sensorless on a 1:5 9inch wheels and the start-up is shiiiiit, soon i’ll probably setup encoders, the whole setup without battery is 14.8kg

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No mucking about! Nicely done.
If you could get some temp sensors you could always try ASS or without you could battle on with HFI mode?

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Great work on the sprockets.

How’s the torque feel for you at that ratio/tire size and what motor amps are you running?

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from testing in the hallway startup makes the motors ‘scream’ but when moving it seams to have plenty of torque, as for the amps each motor is set to 120a you may ask why, simple because why not :crazy_face:

i have temp sensors and was thinking of trying ass, but can’t be arsed rn with installing the fw for it

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Is there a specific reason why you didn’t used platewheel sprockets and just drilled them out?
I mean for the wheel sprockets.
They are usually cheaper than those you used and the middle part gets drilled out anyways.

mainly because i forgot plate sprockets existed, but the hub on the sprocket allowed me to clamp it in a vice while drilling it and the hub is made from a large hunk of decent steel which i most likely will reforge into tooling

took her for a spin today. i do miss the torque of MUD MONSTER but it is still quite good and for it’s purpose it is plenty. one big positive to bunny hopping a 33kg board is this one is nothing in comparison. and stability at high speed is crazy while i can still carve hard on it.

did some maintenance on the board after bout 60miles on it, first waxed the chain in motorcycle chain wax, this stuff works wonders on chains keeps the dirt out of the links and keeps them lubed, so no more ‘crispy’ chains.
adjusted the tension on the motors to account for chain stretch, re-added thread locker to some screws which needed it. had a bag made to put the batteries in with padding


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wouldn’t be a build of mine if i didn’t break something
@rich do i get to join the club now :stuck_out_tongue:

bent the front axle after i landed heavy after the the board ‘ran away’ from me- @Trampa you know whats going on?

also broke the clasp on my vesc box

and crushed the carbon fiber mount :confused:


gonna do a lil board mix up of parts

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Daaaaaamn :flushed:
Are you good bro?

Don’t worry, now you are one of the leaders of the club :sweat_smile:

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yeah i’m good, my pads worked a treat so only a scuffed finger. the board is a lil beaten up after it decided to do full throttle at the top of the ramp and the motor mount dug a 2 inch chunk from the bmx pump track

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Axle straight again :crazy_face:
Time to break some more shit

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Just pre bend them in anticipation :metal:t2:

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