Parallel cam indexer provides high-performance throughput

The challenge in any special-purpose machine design is to achieve consistently high throughput of quality products.

Multi-color printing equipment used to print retail beverage cups requires accurate positioning and a complete stop to minimize any vibration during the print process. This is achieved using a Camco Model 662P indexer. The unit is "Type 2," which means that two indexes are produced for each revolution of the input shaft.

A 300 RPM input speed produces 600 indexes (printed cups) per minute. Actual index time is 50 milliseconds and dwell time for printing is 50 milliseconds. Positioning accuracy is within ±.002 inches and repeatability is within ±.001 inches.

To learn how IMC can help you achieve accurate, high throughput, call your IMC sales representative today. With their expertise in high-performance motion control, IMC sales engineers will help you find the optimal indexing solution.

Tight connections are 'key' to smooth, worry-free indexing

A basic index motion is much like driving a car in stop-and-go traffic. Passenger comfort depends on a smooth acceleration and a smooth stop.

With high-speed indexing (or any speed indexing, for that matter), tight connections guarantee that driven members are displaced exactly as intended: If the driven member is in the exact desired point in space as a function of time (x = f(t)), then smooth acceleration and de-acceleration naturally follow.

Using the car-and-driver analogy, the passenger should be strapped tightly in the seat and there should be no backlash in the car’s drive train. The indexer’s cam contour (driver’s foot on the gas and brake pedals) then provides the ideal displacement, velocity and acceleration.

IMC-Camco-Ferguson recommends the following rules to guarantee smooth motion:

• Driven output members such as dials should be doweled to the indexer face and output overload clutch.
• Keystock should be ground to fit each keyway, with no backlash in the key/keyway interface.
• Shaft couplings should have an interference fit and not depend on the keyway for tightness.
• If belts and pulleys are used, toothed belts are preferred, along with adjustable tensioning idler pulleys to remove any slack.
• Motors and input shafts should run at constant speed, to prevent inducing additive acceleration and jerk in the indexer’s output kinematics. In constant-running motor applications, flywheels can be highly beneficial.