Calculating torque

[jakovn]

I tried to understand torque but just got lost in the formulas...
What torque do I need to be able to lift 1Kg on the lever on the distance of 1m

------o------[1kg]

"o" is motor, --- is lever

I want to do it with stepper, but when I hold the lever with hand, it just skipps to other full step. I want to be able to calculate needed torque and simple formula for the above would be of great help

Thanks

[Al_The_Man]

The holding torque is often stated on the motor oz-in etc, this is the maximum torque the motor is capable of and will resist any force up to this value.
If you want to know an unknown torque, you need the voltage rating of the motor and supply the motor with this constant voltage, the torque can then be measured by pulley and spring scale for e.g. and tension applied until the break-away torque occurs.
Al.

[jakovn]

OK, but what exactly means
Holding torque: 0.6 Nm
Detent torque: 0.12 Nm
in practical sense? Lifting weight or similar?

[rcpilot82]

what about a counterweight?

[Al_The_Man]

Originally Posted by jakovn OK, but what exactly means Holding torque: 0.6 Nm Detent torque: 0.12 Nm in practical sense? Lifting weight or similar?

Holding torque is as I explained in the first post, only oz-in instead of Nm, you can convert if you wish.
The detent torque is usually the force required to rotate the motor when it is de-energised.
Other may elaborate on this as I do not customarily use steppers in practice.
Al.

[jakovn]

Thanks, I understand now. Pulley is this "inch" and weight is "oz" in the formula... I thought it is more complicated.

So if the pulley was 1m radius, and I wanted to lift 1 Kg, then I need:
1m*1kg*9.8 (gravity)=9.8Nm

[elamaranv]

Hi,

I have designed a CNC Machine where in the X axis bed total weight is 100KG.
Kindly let me know how to select the torque of the stepper motor for it to push the 100kg load.

The diameter of the lead screw for x axis is 30mm.

Kindly let me know if there is any formulae for it.

[Al_The_Man]

Originally Posted by elamaranv Kindly let me know if there is any formulae for it.

http://www.electromate.com/technical...morgansoftware
Al.

[BillTodd]

By a strange coincidence I was calculating forces this morning

A 1Kg weight applies a force of 1kg x 9.81m/S/S (acceleration due to gravity) = 9.81N so, to hold up 1kg at 1m requires at least 9.81Nm of holding torque.

BTW
1lb (which is used for both weight and force) = 4.45N
1ftlb = 4.45 x 0.305 = 1.356Nm