Torque Needed to Push a Steel Disk (Mover)

Review Newton's laws of motion. You should now be able to translate these laws into the rotational parameters of torque and moment of inertia. You should also know that the only torque you will need once you are at any operating speed will be the torque to overcome any drag component. There are a number of methods that you can apply to measure this drag or to predict this drag. I would expect a student's senior project to include either a measurement or prediction of this drag. It would be best to do both and to briefly discuss the discrepancy, if any, between the predicted and measured result.

Now go earn your grade.

well that was my question in the first place, the torque that i need to move that disk?. if i get that then i can over come that torque easily and can get the rest of my components thanks

Excuse me but this is your senior project, not my senior project. You will be getting a grade for demonstrating everything you have learned in the past few years of schooling. So far you've yet to demonstrate here an understanding of what torque, the moment of inertia or any other kinematic parameter that your system must deal with. The only thing that you've asked is what torque this platter will require to move at a constant angular velocity. Well here's a hint.

The reason I cannot tell you how much drag the platter requires for constant motion from the information you've given us is not because I'm a smug jerk. (Some people here have accused me of this, I must admit. ) The list of information you've given does not provide enough information to even attempt a guess at the drag coefficient. I don't know the type of bearing this platter will be using, the orientation of the platter with respect of gravity or how much drag the parts of your step down transmission will be adding. Without knowing the dimensions of this 30 lb platter or where the axis of rotation will be I cannot even tell you how quickly this motor will get your platter up to any rotational speed.

I'm afraid to say this but right now it looks like you've wasted your time and money at your school.

A sketch would help.

The required torque would depend on how much mass is being accelerated how fast, the coefficients of friction of the various devices supporting it, etc.

The recipe is incomplete without having assessment of Break Horse power (BHP).

Any Senior should understand that clutter; Quote "output torque of the gearbox is pre-determined to a max value of some sort value" is a detriment.

A DC motor is gifted to be of variant speeds and you have the choice to select one of the methods of speed control.

Project parameters i.e. Output requirements are very well defined, what could make sense was the quest to find an optimum sized motor, or if the motor size is binding as well calculation of gearing ratio to maintain requisite torque at the output while the speed of prime mover remains a factor of gearing ratio and fixed output torque.

What do you mean by a "mover"?

Does the "mover (disc)" slide along a level surface of some sort as it it moved?

What is the coefficient of friction between the disc and the surface?

Is there a grade involved?

How quickly must the disc and any load connected to it accelerate?

Perhaps the acceleration requirement requires more force than the eventual sliding at a constant speed... or vice versa. Which is it?

If you have the answers to these questions, the rest is very easy. For whatever it is you are moving, a force will be required to accelerate it, and a force will be required to overcome friction. Translating the required force into a torque and lever arm is the sort of thing that a senior can do blind-folded. The math to figure the speeds and forces is the sort of thing that a middle school student can do. I can't see where the problem is. Perhaps you could supply a sketch.

i already got the torque, and problem is solved thanks