Hi all

First time posting, apologies that it's not the usual post around these parts. I usually do this sort of thing solo but after all the planning I've done so far I don't want to end up spec-ing my project wrong so was hoping for a second opinion or if not alternative suggestions.

I feel I'll be requesting the help of the chaps across the pond at the moment as I think my fellow crumpet and tea lovers are sleeping or hibernating through the harsh weather in their RC sheds waiting for the better weather to come back around like myself.

Long story short I'm building a OneWheel with some brushless motors that I'll be welding some brackets to mount inside a GoKart wheel that I have sitting next to me with bright eyes and a bushy tail.

There will be 1 brushless motor each side inside the hub, There's just enough room in the wheel I have for them to fit snuggly inside without extending out beyond the rims and adding unnecessary width.

The motors I've got planned are 2x 270Kv 1820W Outrunners (https://www.ebay.co.uk/itm/152558299902) And I'll be using the absolute max these boys will take being 8s packs (or a few smaller ones dumped in series, depends on availability and space)

From my A-level physics and Maths I've attempted a rough estimation of the acceleration these will give me as I don't want to hop on, tilt the board and find myself nosediving into the pavement because the motors are not up to snuff. That and I'm concerned if they can do it will they accelerate fast enough to even bother having it.

Equations I've used (most likey in the wrong application) are below and using 2 of these motors with a total weight of 70Kg (my weight plus the board assuming it is around 11Kg) I'm getting around a measly 0.5M/s^2 which I would find laughable if not for the fact I might be right

RPM Calculations

270 x (8 x 3.7) = 7992RPM

Torque Calculations

3640 x 60 / 2 x 3.14 x 7992 = 4.35Nm

Force Calculations

4.35 / 0.14 = 31.07N

Acceleration Calculations

31.07 / 70 = 0.44m/s^2

With something as small as less than half a meter per second per second I'm doubting the feasibility and might opt for dicing the wheel and welding an E-Bike hub motor in there. Are my calculations correct / utilization wrong or am I correct in thinking even 2 E-Skateboard rated motors are not up to the task?

Any help would be much appreciated, I'm more than happy to share the plans and if anyones interested actually update the thread with my progress

Kind regards

Lia ~ <3

First time posting, apologies that it's not the usual post around these parts. I usually do this sort of thing solo but after all the planning I've done so far I don't want to end up spec-ing my project wrong so was hoping for a second opinion or if not alternative suggestions.

I feel I'll be requesting the help of the chaps across the pond at the moment as I think my fellow crumpet and tea lovers are sleeping or hibernating through the harsh weather in their RC sheds waiting for the better weather to come back around like myself.

Long story short I'm building a OneWheel with some brushless motors that I'll be welding some brackets to mount inside a GoKart wheel that I have sitting next to me with bright eyes and a bushy tail.

There will be 1 brushless motor each side inside the hub, There's just enough room in the wheel I have for them to fit snuggly inside without extending out beyond the rims and adding unnecessary width.

The motors I've got planned are 2x 270Kv 1820W Outrunners (https://www.ebay.co.uk/itm/152558299902) And I'll be using the absolute max these boys will take being 8s packs (or a few smaller ones dumped in series, depends on availability and space)

From my A-level physics and Maths I've attempted a rough estimation of the acceleration these will give me as I don't want to hop on, tilt the board and find myself nosediving into the pavement because the motors are not up to snuff. That and I'm concerned if they can do it will they accelerate fast enough to even bother having it.

Equations I've used (most likey in the wrong application) are below and using 2 of these motors with a total weight of 70Kg (my weight plus the board assuming it is around 11Kg) I'm getting around a measly 0.5M/s^2 which I would find laughable if not for the fact I might be right

*Power = 3640W*

RPM/V = 270Kv

Wheel Radius = 0.14m

Total mass = 70kgRPM/V = 270Kv

Wheel Radius = 0.14m

Total mass = 70kg

RPM Calculations

*RPM = Kv x Voltage*270 x (8 x 3.7) = 7992RPM

Torque Calculations

*T = P x 60 / 2 x Pi x RPM*3640 x 60 / 2 x 3.14 x 7992 = 4.35Nm

Force Calculations

*F = T / r (Radius of my wheel)*4.35 / 0.14 = 31.07N

Acceleration Calculations

*a = F / M*31.07 / 70 = 0.44m/s^2

With something as small as less than half a meter per second per second I'm doubting the feasibility and might opt for dicing the wheel and welding an E-Bike hub motor in there. Are my calculations correct / utilization wrong or am I correct in thinking even 2 E-Skateboard rated motors are not up to the task?

Any help would be much appreciated, I'm more than happy to share the plans and if anyones interested actually update the thread with my progress

Kind regards

Lia ~ <3

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