Torque on shaft due to impact loading during rotation

[Spoolx]

Hi All,
I am trying to determine the correct equations to apply with a problem I have run into at work.

Basically I have a shaft with a cutter with straight flutes, I am trying to find out the torque load on the shaft when the cutter flutes make contact with the material they are cutting.

Any help would be appreciated.

Thanks

 

[Spoolx]

Also, Maybe it would be easier to just calculate the force on the flute and turn it into a torque that way?

I am not having a lot of luck calculating the force though.

Thanks

 

[Baluncore]

Maybe put a lever arm and spring balance on the cutter shaft and start a cut by hand in the material. That will give you the torque needed to commence a cut. It does not include the inertia of the cutter head that is driven by the shaft.

Alternatively, if you can monitor the average motor power while idle and while cutting, subtraction will identify the total energy flow to the cutters. You can measure the angle over which the cutter is in contact with the material, and given the number of cutters and RPM, you can work out the force needed to push a cutter through the material. From that you can get the change in shaft torque.

You could just avoid the calculation by changing to a helical cutter head which will have a constant torque, better finish and chip removal. As an example, a Shelix Spiral Cutter with carbide indexable inserts. http://www.byrdtool.com
Yes, they are expensive, but in production they pay for themselves quickly. http://www.byrdtool.com/planers.html