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.

I am "sparring" with Grok 3 on how different elements can change the performance on the rig. Ended up moving away from hoverboard motors, and instead focus on a 6dof with linear actuators on a stewart platform design.

Grok is awesome - far more happening there than just a rehash of what it finds online.

It considers what I want (Thanos, 6dof stweart, maximum responsive, aim at 500mm/s 3G), then it calculates specs of the motors I find, show what they can offer in performance on a 6dof. Compares with gears vs. DD, and different actuator designs and efficiencies. It then suggests upgrades and changes and even give an estimate on how the rig will feel in car/plane/space sims.

I am down to a detailed shopping list and suggestions of where to go buy everything. ;-)

Latest plans are making linear actuators using 110ST-M06030 (220v 6NM 3000RPM), AASD-15A, Thanos, 10 mm pitch ball screw, 500 mm stroke. Should result in responsive and solid performance; <5ms, 500mm/s, up to 3G.

I have never built anything like this, but with Grok as support I am confident this will be manageable. ;-) Will make another build/project thread when I get started.

We will see.. hopefully I have a functional 6dof stewart platform before years end.

My Grok plans. Only problem is, I don’t have $10k.. yet.

Plans for a DIY 6DOF motion platform to achieve **4G acceleration** and a **500 mm stroke** at a **500mm/s** using the **110ST-M06030 servo motors** while staying within your $10,000 budget, here’s a complete and tailored actuator design.

This setup ensures high performance and immersive realism for your simulation experience, whether it’s racing or flight simulation.

---

### Design Overview
- **Acceleration**: 4G (39.24 m/s²)
- **Stroke**: 500 mm
- **Speed**: 500 mm/s (0.5 m/s)
- **Payload**: ~200 kg (user + cockpit)
- **Motor**: 110ST-M06030 (1.8 kW, 6 Nm rated torque, 3000 RPM)
- **Budget Goal**: ~$4,000-$5,000 for six actuators, leaving room for frame, controller, and cockpit

The design leverages the motor’s capabilities with a ball screw and linear guide system to meet these specs efficiently.

---

### Actuator Performance Requirements
For a 200 kg platform, the load isn’t evenly split across the six actuators in a Stewart platform, but for simplicity, we assume each actuator handles approximately **50 kg** under dynamic conditions (e.g., tilting or acceleration).

#### Force Calculation
- **Acceleration Force**:
\( F_{\text{accel}} = m \times a = 50 \, \text{kg} \times 39.24 \, \text{m/s}^2 = 1962 \, \text{N} \)
- **Gravity Force**:
\( F_{\text{gravity}} = m \times g = 50 \, \text{kg} \times 9.81 \, \text{m/s}^2 = 490.5 \, \text{N} \)
- **Total Force per Actuator**:
\( 1962 \, \text{N} + 490.5 \, \text{N} = 2452.5 \, \text{N} \approx 2500 \, \text{N} \) (rounded up for safety)

Each actuator must deliver **2500 N** to achieve 4G acceleration while supporting the platform’s weight.

#### Speed and Stroke
- **Target Speed**: 500 mm/s
- **Stroke**: 500 mm
- **Motor Speed**: 3000 RPM
- **Ball Screw Pitch**: 10 mm
Linear speed:
\( \text{Speed} = \frac{\text{RPM} \times \text{Pitch}}{60} = \frac{3000 \times 10}{60} = 500 \, \text{mm/s} \)
This matches your requirement perfectly.

#### Torque and Power
- **Torque Required**:
Using a 10 mm pitch ball screw with 90% efficiency:
\( T = \frac{F \times \text{Pitch}}{2 \pi \times \text{Efficiency}} = \frac{2500 \times 0.01}{2 \times 3.14 \times 0.9} \approx 4.42 \, \text{Nm} \)
The **6 Nm** rated torque of the 110ST-M06030 exceeds this, with peak torque (15-18 Nm) handling short bursts.
- **Power Required**:
\( P = F \times v = 2500 \, \text{N} \times 0.5 \, \text{m/s} = 1250 \, \text{W} \)
The motor’s **1800 W** capacity provides ample headroom.

The motor is well-suited for this application, delivering the necessary force, speed, and power.

---

### Actuator Components
To support a 500 mm stroke and 4G forces, the actuator design includes:
1. **Servo Motor**: 110ST-M06030, 1.8 kW, 6 Nm
- **Cost**: ~$300
2. **Ball Screw**: SFU2010 (20 mm diameter, 10 mm pitch, 600 mm length)
- 600 mm length accommodates the 500 mm stroke plus nut and supports
- Rated for ~4000 N, exceeding the 2500 N requirement
- **Cost**: ~$120
3. **Housing**: 40x60 mm aluminum extrusion, 700 mm length
- Extended length fits the motor, screw, and stroke
- **Cost**: ~$40
4. **Linear Guide**: HGH25 rail + block, 700 mm
- Provides stability for the longer stroke and high forces
- **Cost**: ~$100
5. **Coupling**: Bellows coupling
- Ensures zero backlash for precise motion
- **Cost**: ~$40
6. **Joints**: 2x M12 heim joints
- Connects actuator to platform/base, handling dynamic loads
- **Cost**: ~$25
7. **Servo Driver**: Matched to motor
- **Cost**: ~$100

- **Total Cost per Actuator**: ~$725
- **Total for Six Actuators**: ~$4,350

---

### Full Platform Budget
To stay within $10,000:
- **Actuators**: $4,350
- **Frame**: $1,800
- Reinforced steel or aluminum to handle 4G forces (~7,848 N total) and longer actuators
- **Controller**: $800
- E.g., Thanos AMC1280USB for precise 6DOF control
- **Cockpit**: $2,500
- Includes seat, direct-drive wheel, pedals
- **Miscellaneous**: $500
- Wiring, power supply, cooling fans
- **Total**: ~$9,958

This fits just under your $10k budget, though sourcing deals or DIY frame fabrication could provide a buffer.

---

### Realism and Practical Considerations
- **Motion Capability**:
- **Speed**: 500 mm/s delivers rapid responses (e.g., rally jumps or aircraft jolts).
- **Acceleration**: 4G provides intense, realistic cues (e.g., cornering forces or takeoff thrust).
- **Stroke**: 500 mm allows broader motion ranges, enhancing low-frequency effects like banking or sustained pitch, compared to shorter strokes (150-200 mm).
- **Space**: Longer actuators (~700 mm retracted, 1200 mm extended) require a larger base (~1.5-2 m). Verify your build area accommodates this.
- **Frame Strength**: The platform must withstand significant forces. Use 5 mm steel or heavy aluminum extrusions, possibly welded for durability.
- **Heat**: Motors running at 1250 W may overheat during prolonged use. Add cooling fans (~$10 each, $60 total) to mitigate this.
- **Software**: Tune motion cueing software (e.g., FlyPT Mover) to optimize the longer stroke, ensuring smooth, proportional movements.

---

### Final Recommendation
Your adjusted 6DOF platform with **4G acceleration** and **500 mm stroke** is achievable with the **110ST-M06030** motors and SFU2010 ball screws. The actuators, costing ~$4,350 for six, deliver **2500 N** each, meeting your performance goals. Combined with a sturdy frame and quality cockpit, the total cost of ~$9,958 fits your $10k budget.

#### Next Steps:
1. **Source Components**: Order the SFU2010 screws, HGH25 guides, and motors/drivers from reliable suppliers.
2. **Build and Test**: Assemble one actuator first to confirm stability and performance.
3. **Reinforce the Frame**: Invest in a robust base to handle the extended actuators and dynamic loads.
4. **Tune the System**: Adjust software settings to maximize realism with the 500 mm stroke.

This setup will provide an exhilarating, near-real-life simulation experience—perfect for rally racing, flight dynamics, or any high-intensity scenario!

I don't see any mention of rotational inertia in your calculations. (Grok didn't tell you?) If I type your numbers in my spreadsheet I only get 2g at 6Nm. But that's still super good enough. You can't sustain that acceleration for too long, anyway. So you can momentarily overload the motor by a factor of 2.

4g is impressive (literally!). Don't forget the emergency stop button.

There will be a large red button!! (Thanos kit has it covered)

I think Grok calculated it at 6NM continuous with maximum at short burst 2-3x (as you mention). he said this was standard for these motors. So theoretically it could easily produce 4G for short bursts.

I asked about rotational inertia, and got a long reply with a lot of calculations (greek to me) and a «you’r all good».

I found a supplier on Alibaba that has the 110st-m06030 servo and aasd-30a drive I was looking for.

Have ordered 1set to try to put together one actuator first.. and if everything works like I hope, I’ll buy the remaining 5 and have them shipped by boat to lower cost.

$230 plus shipping and vat. Not bad for these kind of server motors and drives.