Mold-Masters Hot Runner, User Manual, Page: 114 / 319

10.6.4 8X00 Series
1. Lightly use silicone grease and install the O-ring in actuator plate at the
bottom of the cylinder bore pocket.
2. Install the cylinder (where applicable) and piston bottom (without the pin
and piston top) into the hydraulic plate.
3. Measure the distance AC and BC.
4. Calculate the heat expansion factor.
Fh = (processing temperature - mold temperature) °C x 0.000012.
5. Calculate the heat expansion of the valve pin.
HE = distance BC x heat expansion factor = BC x Fh.
6. Cut pin to calculated length “L”.
• HY8400: L = AC - 36.35 (1.43) - HE + 0.3 (0.01) + CD [mm (in.)]
• HY8500: L = AC - 36.35 (1.43) - HE + CD [mm (in.)]
• HY8700: L = AC - 59.70 (2.35) - HE + CD [mm (in.)]
• HY8800: L = AC - 59.70 (2.35) - HE + CD [mm (in.)]
7. Grind the valve pin tip to fit the cylindrical gate. Refer to the system gate
detail.
8. Assemble the hydraulic unit.
9. Heat the Hot Runner system to processing temperature.
10. Soak the pin in the Hot Runner system for 10 minutes to achieve the
maximum heat expansion of the pin at the processing temperature.
NOTE
Mold cooling should be running.
11. Measure the distance CD in the heated condition. Check that the head of
the pin is seated.
12. Calculate the dimension to be ground (L2). L2 = CD (measurement) - CD
(specified).
13. Grind the pin end to remove L2 (finish cut).
10-8
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HYDRAULIC / PNEUMATIC ACTUATORS
Hot Runner User Manual