GPX and GPC Support

This page provides support for the GPX and its variants the DC, WCI, and T, as well as the GPC.

Looking for GPX and GPC parts?

At the bottom of this page is a Parts Ordering Form.

Common Issues

Why is my grinder not grinding as well as it used to?

There are potentially many culprits to the decrease in grind quality over time of your grinder. However, with regular maintenance, your grinder should easily be able to be achieve a grind as good as the day it was built.

  • Replace your discs if they are dull. Depending on the grind, your discs may need replacement after 60,000 lb (27,000 kg) of coffee or even sooner.
  • Recalibrate your grinder regularly, depending on your usage.
  • Periodically clean the inside of your grinder (locked out of power)
  • Make sure that you are not missing any parts and to inspect the adjusting screw (and bearing), detent plate, and dial plate if experiencing poor grind.

The grinder is “on,” but hardly any coffee is coming through the grinder and it is very inconsistent.

Your 3 phase motor may be wired in reverse. Swap any two of the three wire leads (typically on the NEMA plug, if that’s installed). Do not swap the ground wire though (typically green). Swapping any two of the three wires will reverse the direction of your 3 phase motor. However, this will not work for single phase motors. If you have a single phase motor, the motor will always run in the correct direction.

Coffee is shooting out of the grinder spout unusually fast.

Check your dechaffing gate. Is it broken or bent?

The rotor isn’t coming off the shaft.

There are two screws (1/4″ 20 Thread screws at 2.5″ length) you can put inside the rotor insert to safely dislodge the rotor from the shaft. Because the tolerance between the rotor insert and shaft is very tight, over time the shaft’s end may wear and create high points. Use a file to level out the shaft’s edges until the rotor can fit and release easily from the shaft.

My grind setting is changing during grinding.

Is your locking nut missing? Sometimes it falls off and customers may forget it exists to lock the dial in place during grinding.

Should I add grease to my motor?

The bearings inside the GPX and GPC motors are sealed. Meaning, even if you add grease to the motor through the grease fittings, the grease doesn’t have anywhere to go. There’s no need to add grease to your motor.

Can I replace the motor?

While in theory the motor can be replaced, we never recommend this as an in-field repair. The burr housing is attached to the motor perpendicular to the motor shaft within a 0.001″ tolerance (about 25 microns), which requires special instrumentation.

Why is my grinder’s amperage overload protector tripping?

Your grinder may not be getting the proper voltage from your power source through all of the leads. You’ll want to test this with a multimeter.

Why does my grinder shut off randomly?

Make sure the right voltage is getting to your grinder. If the voltage is too low, the motor draws more amps than is allowed by the overload relay inside the power box. You can use a multimeter to measure voltage and a clamp meter to measure amperage. For reference, the overload relay setting on a GPX should be the following:

220 V single phase model, this limit is set to 19 A
220 V 3 phase model, this limit is set to 12 A
380 V 3 phase model, this limit is set to 6 A
460 V 3 phase model, this limit is set to 6 A

For a GPC model the limits are different. Call us if you need the limits on your GPC overload relay.

How to Replace Discs

Dechaffing Gate Explained

How to Clean a GPX

How to Calibrate a GPX

Proper Use of the Dechaffing Gate

How to Replace the Dechaffing Gate

Testing Voltage on Single Phase GPX

Testing Voltage on a 3 Phase GPX

Changing an Overload Relay on a GPX

Changing GPX.WCI Coolant

Testing Voltage on a GPX.WCI


Looking for GPX and GPC Parts?

Please first determine which model of grinder you have. By looking at the motor plate you can determine this.

  • GPX, GPX-T and GPX.WCI grinders all have 3 horsepower motors. If you see “3 HP” on the motor plate, then you have a GPX.
  • All GPCs have 5 horsepower motors. All GPX.DCs have 5 horsepower motors. If you have only one hopper, and see “5 HP” on the motor plate, then you have a GPC. If you have two hoppers (dual-sided), and see “5 HP” on the motor plate, then you have a GPX.DC.

The PDFs are password protected. The password is on your grinder’s sticker. Or call our main phone number for password.