Re: Rack and pinion how to figure torque and pitch angle why 14 deg

Dear Sir:

Use of the 20 degree PA pinion and rack is the better choice.
Typically you would spring load the pinion into the rack to eliminate
backlash. You can calculate the separating force which would be the
Tangent of the pressure angle, 20 degrees (.364 is the result). This
would mean that if you have a driving force of 50# due to
acceleration + frictional drag, the spring engaging force would need
to be greater than 50 x .364 or 18.2#. Also note that the pivot
point for your motor/gearbox should lie *ON* the Pitch Line of the
gear rack; this will result in equal engaging forces for motion in
either direction.

Regards,
Jack C.

>
> > I know how to calculate the torque by belting or gearing what are
> > the equations for a rack and pinion. Also why you have to use 14

deg

> > There seams to be more selection at 20 deg.The Motors I have are
> > Small and I need to be able to move the gantry head at
> > 800 inch per min I building a burn table and want to use rack and
> > pinion I need to know how much increase in torque using what pitch
> > gear on the pinion.
> > Thanks Randy
>