This post will help guide you through GW-XT wedge grip setup and operation on your universal testing machine. GW-XT wedge grips are high capacity, easy-to-use wedge grips that feature a crank to open and close the door of the grip.
More information on our wedge grip offerings can be found here.
1. Installing the Grips
1.1. Place female end of grip onto male eye end. If adapters are used, mount the adapters first, then follow the steps below.
1.2. Align the male and female end pin holes and insert pin from the rear of the machine so that the handle is facing the operator.
1.3. Tighten locking nut with spanner wrench to eliminate axial play
between grip and eye end.
1.4. Repeat for upper grip.
2. Grip Usage
2.1. Use the crank handle to open the door latch to the upper and lower grips.
2.2. Use the crank handle to secure the sample in the upper grip by rotating the pinnion clockwise. Before tightening the sample in the grip, close the door and secure the door latch. Make sure the ends of the test sample are engaged with at least 75% of the insert. If the testing machine controller is indicating load, press the ‘ZERO’ button. NOTE: If vee inserts are installed for rounds, sample alignment will be automatic. If inserts are installed for flats, make sure the sample is properly aligned in grip (see images below). If you would like to fabricate fixturing to ensure proper grip alignment for flats, the fixturing can be fixed to the grip with the tapped holes located throughout the grip body.
2.3. Move the crosshead or piston to ensure at least 75% of the lower grip faces are engaged with the opposite end of the sample. Close the door to the lower grip and secure the latch.
2.4. Use the crank handle to secure the sample in the lower grip by rotating the pinnion clockwise. DO NOT Zero out the load again, the clamping action of the wedge grips will preload the sample.
2.5. Grip includes threaded hole to allow for custom made alignment finger to be used. Alignment finger is a metal insert against which the sample can be placed to facilitate faster sample replacement.
3. Changing Wedge Faces
3.1. Apply the handcrank to the pinnion, and turn CCW until the grip opens all the way.
3.2. Apply the handcrack to the doorlatch, and open the door.
3.3. Remove the wedge grip faces one at a time.
3.3a. Loosten the socket head cap screws and remove the retaining rail.
3.3b. Slide the wedge face towards the retaining rail to remove them.
3.3c. Place the wedge/rail pairing on a clean surface.
3.3d. Repeat the process, removing the other wedge/rail pairings.
3.4. Inspect the grip faces to determine if they need to be cleaned and/or lubricated.
3.5. Slide the new wedge faces into the grip. Make sure a insert pair is properly aligned so that when fully tightened the insert noses contact each other.
3.6. Replace the retaining rails and tighten the socket head cap screws using a 5mm metric hex key.
3.7. Turn the pinion CW and test the grips ability to close and proper insert alignment.
4.1. Keep the grips clean and free from sample fragments.
4.1a. Remove the wedge grip faces before cleaning them.
4.1b. Use a stiff brush to clean the grip faces
4.2. If moving surfaces are binding, use anti seize copper grease if applicable.
4.3. If the faces are worn or damaged, contact ADMET for replacements.