Originally Posted by darsdon

I'm trying to calculate the forces on a horziontal scew auger but am confused how to start ?? any help ???

Care to expand on the forces you are considering?

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Oh, and please don't cross post. ■

Sounds like my wife's Spong kitchen mincer!

At that size I'd probably make a prototype and test it. ■

In one respect the enquirer has given his own answer, as in his case the value required is 300N. However, I suspect that his real interest is in the torque required to produce this value. The torque resulting from a force at the end of a helicals crew depends on the axial load applied at this point, the inclination of the flight face in contact and the friction coefficient of the flight surface with the product. Whereas the blade helix angle varies from the flight tip to its root at juntion with the shaft, the dominant area is near the periphery. This can by crudely treated as the mechanics of a rotating wedge on the bald at a geometric mean diameter for a reasonable approximation. To this must be added the torque to convey the material, deal with any shear if the inlet is flooded and overcome tip drag and possible trapping in the clearance layer between the screw flight and the casing at the rate of feed involved. This is a much more detailed analysis and highly dependent on the nature of them material being handled and the circumstances of the equipment geometry. For such a modest duty, a one off appliciation would be best undertaken by a trial, if the drive specification were sensitive, or accept the cost of supply by a specialist manufacturer. ■