D-Box type motion using DC Motor/Gearbox units

[Roadster2]

Originally thinking of building a platform similar to Floriske (http://www.x-sim.de/forum/viewtopic.php?f=37&t=129), using two DC motor/gearbox units I am thinking instead of using four of these units, one at each corner in order to obtain a D-Box type motion system, using the DC motor/gearbox units in place of expensive actuators. This would have the advantage of adding a third DOF (Heave) and also leaving the simulator much closer to the ground making it easier to get in and out.

Can anyone tell me if the X-Sim software can be used to drive such a setup. I'm still investigating controller/driver options but at the moment am thinking of using four Pololu JRK 12V12 boards.

If anyone knows of a reasonably priced 12V 40A Switch Mode power supply then let me know as I will need four of them.

Thanks

[floriske]

The problem with what you are describing is that the motors will have to cary all the weight and you would need some very strong motors for that (motors the jrk's can't handle).

The only way to overcome this is by using a center column with a spring or cylinder (e.g. Like aldoz) but this will result in a higher platform instead of lower.

[Roadster2]

Hi Floris. You could be right but the D-Box actuators seem to manage and they don't look to be that big. I don't know the specs. of the particular D-Box actuators but the specs. on alternative actuators from a Polish company are 1800N Thrust, 200mm movement at 120mm/sec.

My F1 cockpit and myself weigh 150kg so each motor unit would need to lift 37.5kg (150/4). Add to this some sort of frame to mount the simulator on but this could be Aluminium to keep the weight down. The motors I have are 0.4Nm so the output from a 50:1 ratio gearbox should be 20Nm or thereabouts ?

As a possible alternative I could perhaps use a small central pivot, giving just enough height for the platform to move through its range of motion without hitting the ground.

[motiondave]

Hello Roadster, if you refer back to a much older x-sim site and look up Aldoz 3DOF, he built one with JRKS and 12v boat winch motors. And by golly it has some lift!
That would be a good start.
I did ask if a 4DOF plug in is available or going to be developed....still waiting for an answer.

[Roadster2]

Hi Dave. Thanks, I'll take look. With motors at each corner it would only be 3 DOF, Pitch, Roll and Heave, but the software would need to drive 4 motors and it's this that I'm not sure whether X-Sim can do.

Thanks

[motiondave]

well, you could use 4 winches, one each corner, that would lift it. As for profiles, some clever profile fiddling would be needed to make a 4DOF from a 2DOF plugin.
As said, I am still waiting for an answer on a 4DOF plugin.