# Topic: Re: How do you estimate the torque needed for a small chopper/blender assembly?

posed by
Chopping solid vegetables in a blender is not much like liquid blending, so all of these estimates are at best just estimates.&nbsp; A four-blade impeller with sharp blades will not have much resistance in a well copped and dispersed mixture, but could encounter much more resistance cutting through solid vegetables.&nbsp; The amount of resistance at the low speed will be very different depending on whether the vegetables are carrots (firm) or tomatoes (soft).&nbsp;As some general rules, based on fluid mixing, the torque required at 2000 rpm will more than 1500 times the amount of torque required at 50 rpm.&nbsp; So the actual range of torques can be quite different.&nbsp; Kitchen experience with food choppers says that the torque at low speeds can be quite high because of the resistance in cutting solid vegetables, although I don't ever remember seeing a chopper that operated at only 50 rpm.&nbsp;
At that speed, you can see the blade rotating at less than one revolution a second.&nbsp;Using a range of experience and process knowledge, I estimate that the maximum torque in a mixed vegetable blend at 2000 rpm could be roughly 0.5 Newton-meters.&nbsp; If the chopped vegetables form a very heavy slurry, the torque could increase to 1.5 Newton-meters.&nbsp; Those values are only rough estimates based on an educated guess at both the processed food properties and the power characteristics of a four-blade chopper.
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