# Calculating Inches/Pulse For Senergy Drives

There are times when you will want to use ConveyLinx and Senergy for more refined motion.  With PULSEROLLER Drives you do have repeatable linear motion at a pretty fine (<1mm) resolution.  So, how do I accomplish this task?  How many pulses will I need to input to our controller to move my product 30 inches?  Here is how you will figure it out.

Constant For Senergy Drive Products:

• All Senergy products (Gear Drives or Rollers) have a constant 30 “Pulse/Motor Rotation.”  This is because our internal motor is a 10 pole motor and has 3 hall effect sensors detecting motion of the rotor. Therefore, to get “Pulses/Motor Rotation” the formula is the amount of Motor Poles multiplied by the amount of hall effect sensors (10x3).

30 Pulses/Motor Rotation = Constant for All PULSEROLLER Drives

Next, we need to figure out the Pulses/Tube Rotation (P).  This is done by multiplying the “Pulses/Motor Rotation” by the Gearbox Ratio selected for the job.  You can find this ratio in the characteristics data sheets of any of our Drives Products.  Let’s say  a “15 speed code” was selected for the application.  The characteristics data chart shows a 15 speed code has a 45 to 1 Reduction Ratio.

• 30 Pulses/Motor Rotation

• 45 to 1 Reduction

• P = 30 * 45 = 1350 Pulses/Tube Rotation

To determine the circumference of the tube we need to know the diameter of the tube and then multiply that by Pi.

• C = 1.9” * Pi = 5.96885”

The final calculation will be governed by your application. You will either need inches-per-pulse or pulses-per-inch.

Let’s call this ratio X and the formula is as simple as X = C/P or X = P/C  See below...

• (1.9” * Pi = 5.96885) / (30 * 45 = 1350 Pulses/Tube Rotation) = .01”/Motor Pulse (inches-per-pulse)

or

• (30x45 = 1350 Pulses/Tube Rotation) / (1.9” * Pi = 5.96885) = 226.1  pulses-per-inch

If you have questions or would like to see a specific Pat's Corner let us know at support@pulseroller.com, by phone at 800-764-63569, or you can find me on Google+ to discuss.