Hi, I run a build thread on endless-sphere (https://endless-sphere.com/forums/viewtopic.php?f=35&t=79241) and decided to show my finished build also here. I started gathering parts for this build in December but did not have enough time to push it forward till easter, I spent them in my workshop and have done most of the work. Here are technical details of this build: 2x EMAX 5345 170 KV 63mm outrunner motors 2x Ollin board company VESC Trampa long 35 with vertigo trucks, superstar wheels and ratchet bindings Underwater Kinetics 206 Ultrabox and 309 Drybox So lets start with the photos:
As You can see 4 5000 mAh 6S turnigy lipos fit nicely in 309 Drybox case.
The problem with the motors was that stator and rotor was held by this round piece of aluminium with set screw, I did not like the look of it, and it would interfere with motor mount not allowing to tension the chain properly so I decided to turn new shafts, with grooves for circlips.
Here You can see the shaft getting keyway milled, I don’t trust small set screws enough
And final product:
Then I bored, keywayed, drilled and tapped sprockets to fit nicely on the motor shafts
After that I had to deal with how to fit all of this electronics and other stuff in this small 206 Ultrabox, it’s easy to fit 2 VESCs in there, but 2x VESC + 4x 2200 uF caps + IXFN200 N07 MOSFET + 200A shunt for ampmeter circuitboard + 200A fuse + circuitboard mosfet switch for front LED light it’s a bit more challenging, so I decided to mill aluminum mounting plate for all of this, which acts a radiator for VESCs lower mosfets.
And the last, most challenging part was to mill motor mounts, I had few attempts since January, but failed every time… until this weekend. I hope Jenso from E-TOXX does not mind my strong inspiration with his design, but… It’s just the best solution for this task Aluminum I used is 15mm thick 7075 grade, I guess it’s strong enough
Here are photos from manual machining process in chronological order:
I’m not a machinist and the milling process took me about 20 hours…
I still have to mill 3 support braces for motor mounts. Unfortunately I trashed 2 sprockets which I planned to use for rear wheels during machining, have ordered new ones, I need them to measure the lenght of support braces for motor mounts.
And here is front light, It’s super bright and has long range, I made special mounting plate for it to not have to drill in the deck.
Oh, and I would forget, my friend wanted to have some fun with borrowed camera so he came to my workshop and interfered in my work, wanting me to do unnecessary things, to record them (burning titanium chips was not the part of eMTB build ) [youtube]x0Zoch6Y9Sg[/youtube]
Update, today I installed hall sensors and termistors in both motors, had to mill stator a little to fit SS411A sensors. They’re spaced 120 degrees apart. Width of sensors is 4.05 mm and the milled gap is 4 mm wide, pretty tight fit, they’re glued with epoxy and secured by kapton tape, termistors are glued with thermally conductive glue, nothing should get in rotors way.
Termistor (left) and one of hall sensors (right) in place, secured by kapton.
One more hall sensor
Additional material from inside of sprockets was cut with jigsaw. Here is milling process in few photos:
I’ll bead blast sprockets and hot blue them to prevent from rusting (motor sprockets too).
Motor mounts finally finished! I milled support braces today, bead blasted everything and will give it to get anodized. Sprockets will be chemically hot blued (and be black as a result).
Picked up motor mounts from anodizing, they look AWESOME! Did hot black oxide on the sprockets in workshop tonight, again, success
Managed to finish this beast today! It’s AWESOME, love VESC and BLDC tool for programming, it’s not so difficult as it looked at the beginning. Speed, power and handling, really impressive. As it was already dark when I was ready to test it, for now are only pics in artificial light, it does not show the beauty of this black anodized mounts. I’m really happy how it turned out, and I learned a lot!
And now of course some pics
Here is how I mounted battery case to the deck, I cut rubber spacers out of 5mm thick rubber, and made special treaded plates out of steel, protruding nut could damage battery. Rubber allows deck to flex and dampens vibrations.
Here is ampmeter screen, it uses 200A shunt to measure current, it’s mounted in electronics case. Nice feature.
And final product of over 4 months of reaserch and development
And the rig itself in natural light:
And I already scratched one of the support braces on asphalt trying wheelie, too much throttle…
Thanks for watching!