Replacing & Calibrating a Pulse Pickup on a 5700-C

This video will explain what a pulse pickup is, how to install it, and how to calibrate it. A pulse pick up is a magnetic trigger that is used to calculate speed and distance.

A pulse pickup can be found on the left rear crawler motor of all network controlled Power Curber 5700 series machines.

With this cutaway motor, you can see the lobes on the motor shaft and the tip of the pulse pick up. The pulse pick up detects these lobes and sends a pulse back to the computer. The computer uses these pulses to calculate speed and distance.

Now let’s look at how to replace one.

• Before starting, pull the 60 amp breaker to eliminate the chance of an electrical short.
• The motor can be hot, be sure that it has cooled before beginning.
• Depending on the model of your machine, the orientation of the motor may be slightly different. This model is a 5700 C Max.
• The first step is to remove the wires from their protective cover. Separate the hose from the brass nipple. Loosen the compression nut at the top of the protective hose. This will allow you to slide the protective hose over the wires.
• Take note of the wire colors, red on the PPU goes to black on the machine. White on the PPU matches white on the machine. And black on the PPU matches green on the machine. Now cut the wires.
• Remove the brass hose barb from the motor housing. It is held in place by a set screw to the right of the barb.
• Next loosen the set screw that secures the ppu from losing its adjustment. This setscrew is to the left of the sensor. Clean any dirt that is present before removing the ppu. Once the setscrew is loose, turn the ppu counterclockwise to remove it from the housing.
• Now we are ready to install the new ppu. Remove the site plug from housing. By looking into the hole, you will be able to see the motor shaft.
• You must be sure that a high spot on the shaft is pointed towards the hole. This means that a high spot is also in the proper position for our sensor. You may have to rotate the motor to get on a high spot.
• On our cutaway motor, we can see that failure to align this correctly will cause damage to your new ppu.
• Now that the shaft is aligned properly, you can insert the new ppu. Turn the ppu clockwise until it bottoms out. This means that the tip of the ppu is touching the motor shaft. Now turn the ppu 1/4 turn counterclockwise to set the clearance between the shaft and the sensor.
• With this done, secure the sensor set screw, and replace the housing plug.
• Now replace the brass hose nipple. Tighten the set screw.
• Now attach the wires of the new sensor to the ones on the machine harness.  Remember to match the colors correctly. Slide the protector hose back into position and secure the hose to the brass nipple. Tighten the compression nut at the top of the hose.
• Reset the 60 amp breaker.

The new sensor is installed, now it must be calibrated.

We will demonstrate this calibration on a 5700C, the procedure is similar on 5700B’s and Super B’s.

Move the machine to a clear place. Mark out a known distance on the ground. In this case, we used 20 feet. On B’s and Super B’s, the distance must be 10 feet.

Enter the calibration menu on the computer. Scroll to the screen for Pulse Pickup calibration. Press start. Drive the machine to your line. Stop the crawlers, but do not press the stop button on the computer. Adjust the distance on the display to match the distance you had measured out on the ground, in this case 20 feet. Now press the stop button.

If you have done everything correctly, the screen will say IN RANGE. If not, the screen will give you an error message. In that case, repeat the calibration routine.

Your pulse pickup replacement is now complete.