Instron 300DX, Operating Instructions Manual

Page: 74 / 96

Chapter 4: Maintenance
74 M47-17027-EN
Equipment and supplies required
•
A suitable stable platform such as a man-lift, stairs, or ladder. The platform must be of sufficient
height so that the operator can reach the tension crosshead.
•
4 mm hex key (supplied)
•
For 300DX -G1 frames: 14 mm hex key
•
For frames with G1-style crossheads: Hex keys, see Table 11 on page 49 for sizes
•
Molykote type GN metal paste
Recommended procedure
1. Clean and inspect grip jaws, this includes all sets of grip jaws, not just the ones in use:
a. Remove grip jaws from each grip pocket, refer to either “Remove grip jaws - G1-style
crossheads” on page 50 or “Remove grip jaws - G7-style crossheads” on page 55
depending on the crosshead style of your frame.
b. Clean lubricant from all sets of grip jaws.
c. Inspect each grip jaw for damage:
• For frames with G1-style crossheads: Check the rack teeth. If the rack teeth are broken such
that smooth operation of the pinion is prevented, the grip jaw should be replaced.
• For frames with G7-style crossheads: The locating boss on the rear of the grip jaw fits into
the recess of the jaw carrier with tight tolerance. Dirt or damage in either area may cause
them to be press-fit together during testing. If damage is found along the edge of the
locating boss, the edge can be filed smooth.
• Check the gripping teeth. If more than 50% of the gripping teeth are broken or damaged, the
grip jaw should be replaced.
• Check the entire grip jaw for cracks. If any cracks are found, the grip jaw should be replaced.
2. For frames with G1-style crossheads: Clean and inspect filler plates:
a. Remove filler plates from each grip pocket.
b. Clean lubricant from all filler plates.
c. Inspect filler plates for damage. Check for bent corners, nicked or galled surfaces, and warping.
If a damaged filler plate can be repaired so that it is flat and the shoulders will still support the
filler plate in the crosshead, then the filler plate may be repaired and re-used. If damage is
severe enough to prohibit repair, then the filler plate must be replaced.
3. For frames with G1-style crossheads: Clean and inspect grip stop plate and bumper plate:
a. Remove grip stop plate from the top of the tension crosshead (refer to step 1 of “Install grip
jaws - G1-style crossheads” on page 46 .
b. Remove bumper plate from bottom of adjustable crosshead (use 14 mm hex key).
c. Clean any lubricant from all plates.
d. Inspect all plates for cracks. If cracks are found, replace the component.
4. For frames with G7-style crossheads: Clean and inspect guide plates:
All equipment and supplies must be supplied by the customer unless noted as “supplied”. For a list of
equipment that was supplied with the system, refer to
“Ancillary parts” on page 87 .