# Motor for rotating platform



## Zakaria (May 24, 2011)

Hi all,

I am doing a project to build a solar tracker. The tracker will consist of rotating platform which will rotate according to sun motion. The platform will be built on four wheels with one or two of the wheels are driven by electric motor.

It will rotate about vertical axis and the platform should be able to rotate with max tangential speed of 1.03 m/min and min tangential speed of 0.017 m/min.

In other words, the platform will follow the speed of sun at this range. The sensor and encoder will be used for this purpose but the platform should be able to rotate with the max tangential speed of 1.03 m/min.

The platform has a mass of 4 tonnes and radius of 10 m and can be modeled as uniformly distributed object.

Can someone please help me to calculate the max torque needed in order to choose the suitable motor for this application? If some information missing for the calculation of torque, please let me know

Thanx in advance


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## palvarez83 (Jun 16, 2011)

Zakaria said:


> Hi all,
> I am doing a project to build a solar tracker. The tracker will consist of rotating platform which will rotate according to sun motion. The platform will be built on four wheels with one or two of the wheels are driven by electric motor.
> 
> It will rotate about vertical axis and the platform should be able to rotate with max tangential speed of 1.03 m/min and min tangential speed of 0.017 m/min.
> ...


The torque needed to be delivered to the platform will depend on how fast you would want it to accelerate ot 1.03 m/min. Also, what is the overall (motor to platform) gear ratio? What is the shape of the platform? It it a simple disk? Is that what you mean by "uniformly distributed"? We need this in order to calculate the momment of inertia (J) .... Torque = JxAlpha. Then you can integrate the equation once to get you rotational speed.


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