Hi guys,
I have already asked/replied/reported here and there but now that everything is done, I feel like summing it all up in one complete build thread. So better get your reading-glasses, there is some serious amount of text coming up 
The most important first: The result in unpolished dirty pics
Why all this
To be honest, initially I only wanted to see if I could design and build a hub motor. This urge was triggered by some esk8 guy converting ordinary BLDCs into hubs on an esk8 forum. My younger self felt challenged to do the same about 4 years ago. At that time, I already had a poor single belt drive lunch box Globe Pinner kind of board but I wanted something stealth. First, I had the time but not the money, then it was the other way round and finally, May 2020, COVID made me have time for it again…
Hub motor build and sleeve casting
Hub motor build and sleeve casting
If you want to read the whole story, click here: https://forum.esk8.news/t/diy-hub-motor-trouble-shooting-solved/40671
Summed up, I built two hub motors around sensored Alienpowersystem 6355 100kV BLDCs:
- CAD design
-
Many hours on the turning machine + little milling in my dark cellar
-
Maytech vs. DIY sleeve casting
Rev. 1 based on the Maytech sleeve MTSKPT9052 which was so tight, that the gap between the aluminium tube support of the sleeve had a radial gap of 0,5mm (0,0197 inch) to the stator. My fat ass (85kg/187lbs) did bend it too much, which caused some grinding here:
-
Only solution at this point was to cast my own sleeves onto a bigger aluminium tube with a bigger inner diameter.
Thanks to @visnu777 ‘s HowTo cast thread (DIY wheel and sleeve casting - #44 by DerSi) I managed to cast some decent sleeves after some trouble with lack of adhesion between PU and aluminium tube:
-
Turning bigger aluminium sleeves
-
Turning the mould parts
-
Casting (first ones without color pigments)
-
Repeat until perfect and then decide to hate the amber color, order black pigments and do another (3rd) pair:
-
Final hub design (without black sleeves and black paint on aluminium parts):
Some photos/videos while building the motor
-
Machining the hanger for mounting seat of motor:
-
Drilling of hanger and hanger bearing adapter in order to lock them with 2 pins:
-
Prior and afterwards of the inner bearing ring adapter:
-
Fitting and first testing of the bearing
:
-
Machining the motor can for the front cover plate/hub and additional bearing seats:
-
First assembly on “prototype” cheap olf belt bord:
-
Assembled hub motor without front cover plate:
DIY Integrated deck
DIY Integrated deck
When I realized, that the hubs would turn out just the way I wanted them, COVID also decided to fuck the world up for another couple of months. So I had the perfect opportunity and excuse to spend further hours all by my self in the garage and cellar.
Appropriately, I couldn’t stand the thought to drive my stealth hubs on that old poor lunchbox Globe build of mine. No! Now I wanted to build it all!
Nice and stealth it should be (yeah, in my country it is illegal to use esk8 faster than 6 km/h in public road traffic). So the only deck for me was an integrated one (of course I had to do the CAD design before, too much time available):
I wanted to have a slim board with all the electronics integrated inside, in a slightly unusual shape made of wood. Spoiler: the wood didn’t work out.
Milling it out of one piece of beautiful wood exceeded my DIY possibilities (and purse) by far. So the compromise was a sandwich board made of 3 layers:
-
Center: watercut aluminium frame (perfect rough template for cutting everything else in shape with DIY tools, screwing things together and way cheaper and more stable than cnc milled exotic wood)
-
Top: birch multiplex (9mm/0,354inch) reinforced with 3 fibreglass layers with milled air channels
-
Bottom: fibreglass box for the necessary cavity directly laminated onto the aluminium frame, covered by a foil in wooden design:
-
Inspired by @glyphiks HowTo Fibreglass thread (Link) and watching some youtube guys I felt ready to this!
-
I ordered material for 2 layers 320gr biaxial and 1 layer 440gr unidirectional glass fibre material for strengthening the birch plank which got screwed and glued to the aluminium frame. The lid was simply cut out and is fixed/removed with 4 countersunk screws to the aluminium frame
-
For the integrated cavity in the mould I used simple wooden boards as placeholder
-
I read some interesting tutorials for building custom loudspeaker cases where they stretch flexy cloth over wooden boxes in order to get a seamless design. In valleys one would keep the cloth down with stapler. I used double sided tape (which didn’t work out completely because the epoxy slightly removed it here and there, so I held it down with wheight in the end:
-
After curing I had a nice and stable shape to apply 4 layers of glass fibre Satin weave cloth laminate
-
Without vacuum I expected quite some bubbles underneath the top PE foil and I wasn’t disappointed
Thus, I did, what every glass fibre enclosure DIY builder has to do: sanding sanding sanding
-
In the end, everything was wrapped in foil (furniture foil, here “dark apple birch chocolate wood “ 5€ ). So cheap but so much of a difference
In the end the deck weighs 3,5kg (7,7lbs) with its size of (94x22x2,1-3,5 cm / 37x8,7x0,82-1,4 inch) and has no flex (toilet paper for scale).
What went wrong:
• Shit load of work! Cannot be underestimated 
• Sanding sanding sanding: next time I would pay more attention to the final layer (tear-off fabric fiberglass or vacuum or just more patience with removing air under the plastic foil). It was several hours sanding by hand and machine till it was somewhat acceptable smooth.
• After the very first ride the bottom fibre glass came off at one small spot. I blame the combination of double-sided tape and epoxy: the epoxy seemed to loosen the tape, yet there was no or not enough epoxy where the tape (too much tape / too little epoxy on small flange) was which lead to poor adhesion. The rest of the connection seemed solid. Nevertheless, I was too scared that the bottom enclosure part might peel off completely over time at top speed/vibrations destroying me and all the precious electronics…so I added some screws (aluminium frame for the win again). Somehow breaks the clean design but safety first!
• Furniture foil is quite sensitive (surprise!). Gets easily scratched, especially edges are endangered 
Part List
Part List
- Deck: Custom DIY sandwich (gf birch/aluminium frame/gf enclosure integrated / foil) 37”
- Trucks: Front Paris v3 150mm 50° / Back NoName 180mm 50° (mounted drop through with Bolzen shock padsS)
- Wheels: Front 90mm Flywheel Clones / Back DIY casted 92mm sleeves
- Drive System: 2x DIY hub motors
- Motors: 2x Alienpowersystem 6355 100kv
- VESC: @YUTW123 2x MakerX Mini-FOC Plus
- Battery: @Simeon 8s4p 30Q with LLT smart BMS(Charge only, Link)
- Enclosure: integrated
- Switch: Alienpowersystem Antispark (blue light switch is mounted towards pedestrian’s side so it’s hardly visible for passing cars and people on the other side of the street )
- Remote: @Stephensound Flipsky VX1
- Telemetry: @rpasichnyk Metr Pro
Specs
Specs
- Top speed: ~50kmh / 31mph
- Range: ~20km /12,4miles
- Total distance travelled (so far): 42km/26miles
- Weight: 8,9kg /19,6lbs
- Size of deck: 94x22x2,1-3,5 cm / 37x8,7x0,82-1,4 inch
- Acceleration: tbd
- Noise: nothing but smacking PU on concrete
Electronics
- Sensored motors in FOC mode
- Motor Current Max: 40A each
- Battery Current Max: 30A out and -6A in (each motor)
- PPM for remote
- Metr Pro via UART
- Too many adaptors and cables
:
Without having planned to do this full build I really love the result. It isn’t perfect for sure, but it is a slim, short enough, light enough, beautiful, super stealth and a pretty fast board for my city/field rides.
Thank you everybody for all your support and inspiration! Reading and learning from you guys became a passion which helped me to not go any more bananas than I have been before during this crazy last year! Stay save and Happy Easter!
Soldering cables and adapters is enough for my skills
The PU itself did not show any surface defects at all although I tortured them up to 90°C/194°F 
