Hi all, I need some guidance on my build, any help would be greatly appreciated!
So I pretty much want to build a pair of freeline skates with a hub motor on the back of the rear foot. I do not need a long battery life, I does not need to be fast, I just need a good amount of torque for small hills
7s battery pack with bms using
Sony VTC4 18650 2100mAh 30A Battery (7 of them) from IMR
Thanks for the video, yea this guy managed to do something awesome with close to nothing! SLA battery, a DC motor and a ON/OFF trigger and voilĂ .
@tristanhood since you use freeline skates,where are you goin’ to put your enclosure for batteries and all? If you can, a geared setup would be better if you go single drive. If you dual drive that’s another story!
You cannot skip the custom frame I think or cut a bit through the standard one (either for motor mount or for the hub).
Maybe you can raise the platform and put electronic there. Or add extra platform around the standard one and put it there, you’ll at least not need to raise your footing. Do you have any design already?
Can you put 70mm wheels or similar? Arcboards sells pulley ready wheels.
You should also add open Hook to keep that thing around your feet and still be able to jump out. Maybe two hooks to be able to climb sidewalks?
I was thinking of thickening the base that the user stands on to make room for the batteries, esc and bms. I am pretty keen on the hub motor within the back wheel, going to machine the frame on a 5 axis milling machine then store the electrical package within a plastic container.
Open hook is a smart idea! riding freeline skates is not easy and i think it’d be smart to incorporate a quick release system that has to be intuitive, easiest would probably be open hook.
I was wondering if anyone could just check out the technical package I have in the first post? would the bms work with those batteries, and would that be enough for the hub motor?
I have attached early sketches for the assignment if people are interested
Nice design ! Careful with the truck design but you must have done your homework already
You should replace the Sony VTC4 with Samsung 20S if you want same range but better power, or go 21700 cells and put some 3000mah or 4000mah cells.
If you really wanna go hub, you really should double it cause single tiny hubs are inefficient to max (if you can achieve 30% efficiency on 1WD tiny that’s a LOT).
Thank you for your help! I can’t wait to order stuff in to start prototyping.
I will substitute for 18650 samsung cells, I don’t need this thing to go really fast, just at max 15-20km/h, i did kind of need torque for small hills though so I will go with two hub motors underneath the rear foot,
Could you recommend a decent bms for 7 samsung 20s batteries?
and could anyone recommend a reliable hub motor other than one of aliexpress? ahaha
IMHO if you bypass discharge and only balance on charge you can use a standard one (I have a tiny 10s BMS for sale haha but maybe you can get an even smaller one if you get a 7 or 8 s and just use the 7s pins),you can also check ebay.
Friction drive refers to using a drive wheel pressed against your actual wheels
It also works if you put a rubber sleeve around the motor can and press fit it between your skate wheels in the middle.
What’s the point ? It’s super simple and compact and you get a reduction ratio due to motor and wheel diameter, so you gain more torque and can try 1WD, just like a belt drive but more compact (and lighter). This should be way enough for your speed and torque requirements. You can also use any standard skate wheels instead of hubs so better ride quality.
Motor is exposed to air so you can cool it better.
The negative : you stress the motor structure so you really need a sturdy motor (maytech has this new fancy motor with two bearings built in). When the rubber around motor wears out, you get slippage so you need to replace at some point.
i think 
looks very interesting no?
I stay here to see more!
