Hoverboard motors?

Has anyone looked into doing a diy version of Ark Dynamics 6dof direct drive solution with hoverboard motors?

Have you already found that other thread about Ark Dynamics?

I did some calculations and have also considered to use BLDC direct drive motors. Hoverboard motors are far too weak (IMHO) but there are some really cheap offers of large (agricuturally used) drone motors on Ali, recently. They have around 4 to 6kW and sell for 70..$100 (used). But together with a suitable driver/controller the price is higher than for an industrial servo, so I abandoned the idea.

Yes, I have posted some in that thread as well.

Talking with Grok these days to go through ideas and solutions. Did find 4kw 90nm hoverboard motors at Ali, but $280 each.. so expensive.

Hopefully Ark Dynamics will deliver their Kits soon.

Check out this. The motors are used so maybe some of them are damaged. But if you order 6 or some more you can send the ones that don't work back.

I need to use Grok planning my build, as I have zero experience. I was planning for a direct drive setup.

Grok says this about these;

Lack of Direct Drive: The A40 motor, designed for drone propulsion, isn't a direct drive motor in the context of 6DOF platforms where direct drive motors are often preferred for eliminating backlash and providing precise control. Using the A40 would require a mechanism to translate its high-speed, high-torque output into the controlled, low-speed movements typical in 6DOF applications.

A 6kW motor running at 5kRPM has a torque of ~11.5Nm. This generates a linear force of 115N with a crank arm length of 100mm. This is not enough to support the weight of a stewart platform. But with additional gas springs or pneumatic cylinders as Ark Dynamics uses them it should be possible to use this motors as sort of "direct drive", I mean without gear. This would surely require some extra cooling and careful balancing and tuning. If it was super cheap it would probably be worth the trouble but it's definitely not. Conventional motors and gears or ball screws are the better solutions, IMHO.

PS: the motors I have linked are marked "non working, need repair". But if you search a bit you can find motors that are used but working for ~$100.

PPS: Don't trust Grok. It's an AI, e.g. a language model that has no tecnical understanding but just repeats what it finds in the internet. That's not necessarily the truth.