Movement platform evolution (2DOF to 6DOF)

In this thread I was building a 2DOF motion platform
https://www.xsimulator.net/community/threads/2dof-plywood-and-aluminum-profile-construction.15400/
It's time to remake it into 6DOF! I think to use linear actuators following example @pmvcda
https://www.xsimulator.net/community/threads/flypt-6dof-brushless-diy-actuators.10799/
The first thing I did was draw a linear actuator. The motors BLDC are used from the 2DOF installation plus I will buy another 4. Ball screws 1605 400 mm long. I plan to get 300 mm of travel. I want to use a 10K ohm multi-turn potentiometer as feedback.

Ah nice, looking forward to your build

If you don't have them already, then I'd go with at least 450mm ballscrews if you want 300mm of travel. Mechanically you lose around 115mm of travel due to the machined ends (11 + 54mm) and the nut (50mm) and limit switches will cost you another 20-40mm.

Yes, you are undoubtedly right. I haven't bought a ball screw yet. According to the 3D model, the stroke was 277 mm with a screw length of 400 mm. It is necessary to think and complete the model completely in order to understand whether this is enough or not. I'm more worried about the hinge fingers at the ends. Enough 14 degree angle or not

Collected the platform model and got the following results.

With a linear movement of the actuator of 277 mm and ball pins at the ends of the actuators with an angle of rotation of 14 degrees, movement along the Z axis was 309 mm, along X, Y - 320 mm, an angle of inclination of 20 degrees in one direction, that is, 40 total along one axis.




The platform turned out, of course, high in the Z axis from 870 to 1179 mm. I will climb from a mini stepladder. If you move the attachment points higher than the seat, you can lower the platform by 20-30 cm, but it will still be high.

My spaceship in model is almost ready

All electrical part in the cabinet from below

Looks solid so far! Keep on going

Some questions / thoughts:
What motor controller do you plan to use? What power supply?
Are you sure you want to put it in wheels? Some users even have bolted their sim to the ground because it was moving and I plan to doing so, too.

I will be using 188W brushless BLDC motors with BLD-300B driver. I used them in a 2DOF rig with worm gears.
https://www.xsimulator.net/community/threads/2dof-plywood-and-aluminum-profile-construction.15400/

Wheels on the platform for the ability to move it around the room. The wheels have a stopper from the rotation of the wheel and the wheel around its support. There were no problems in 2DOF. It is necessary to assemble the installation and look at its stability and vibrations. Removing the wheels is, in principle, not long. Perhaps I can think of retractable wheels for movement, and during operation, full fixation to the floor

188W seems extremely low. Other 6dofs, including mine, do use motors with around 2000W power. Keep in mind that you lose a lot of torque because you remove the gearbox. Also your 2dof had to move only a bit of weight and not 100% of it, like the 6dof does.

In this project, a person uses BLDC motors 220W and 60 Ncm.
https://www.xsimulator.net/community/threads/flypt-6dof-brushless-diy-actuators.10799/
I have 188W and 0.6 Nm written on the engine. On the Internet, a special ball screw calculator showed that with a torque on the engine of 0.6 Nm and a ball screw efficiency of 90%, the axial force is 70 kg. The linear actuator has an inclination angle of 55 to 65 degrees to the horizontal surface, so the vertical force from one actuator is about 70 * sin60 = 60.6 kg. All six drives will in theory lift 360 kg. If I'm not mistaken, then it seems like these calculations

The calculation is for static objects. The actuators can hold 60.6kg, but are not able to accelerate.
Maybe it works with your motors and I'm wrong, only a test with a prototype can show if the actuator has the performance you are looking for

As soon as the ball screws arrive, I will try to assemble one linear drive and load it

Drew a diagram of electrical connections. I will use ESP32: 2 cores, high frequency compared to arduino, 12 bit ADC (analog to digital converter), many pins with PWM should do the trick. Cost 2.5 euros

Good to see that you are switching live and neutral!
On the DC side you should connect all GNDs together at one point. This reduces EMI issues and possible faults from high currents through small PCB traces.

While I wait for the ball screw, motors with drivers, I started the 3D printing process. I print with ABS plastic with 60% filling. I think this will be enough for strength.

This is a purchased aluminum profile 20x40 and 40x40 immediately cut by the company according to my dimensions. I decided to cut the threads from the end surfaces myself with an M6 tap.

Linear actuator assembly started!

Printing plastic parts takes a long time.
He began to assemble the base from a bar of wood and plywood

Collected the first linear actuator. I'll get two more soon. For the rest, you need to wait for the delivery of ball screws from China, and there the New Year has begun, so the delivery may be delayed. Happy Chinese New Year everyone !!!

Here is a video of the work. I did not test it at maximum speed, as I launched it without limiters, I was afraid that I would not have time to stop it. Effort on first impressions is sufficient

I started assembling a cabinet with electronics

Sawed holes in the cabinet and printed decorative covers for connectors, fans, buttons and cable outlets. I removed the door hinges, printed the handles and made a removable door for easy access to the electronics