# Hot Runner & Control Systems

Straight-Shot Hot Sprue Bushings ER-Series Straight-Shot ™

85

The DME standard ER-Series Straight-Shot (Short Style) is intended to suit the requirements of smaller injection molding machines and is supplies with a 7 / 8 " A dimension. The A dimension can be altered to suit the particular molding application. NOTE:  5° heater lead is standard. For 90° lead, add “90” to end of item number (e.g., SSBT4407ER290). NOTE: The expansion factor must be taken into consideration prior to machining for and installation of the bushing. This factor (BE) must then be added to the A dimension. The formula for determining this expansion factor is, as follows: BE = “A” dimension x 0.00000633 x nozzle set point - 68ºF (assuming the mold is at 68ºF during operation). If mold temperature is different, substitute 68ºF with actual mold temperature. EXAMPLE: Given a setpoint of 500°F: BE = 1.375 × .0000063 × (500 – 68) = .004 thus 1.375 + .004 = 1.379. Please note that the above information is given as an example. Variations may occur based on mold configuration and cooling factor. In some instances, it may be necessary to obtain an empirical factor.

Short Style

ER-Series Straight-Shot Hot Sprue Bushings (Short Style)

WITH 240 VOLT HEATER ITEM NUMBER SSBT4407ER2 SSBT0407ER2

A DIMENSION

R

1 ⁄ 2

7 ⁄ 8

NONE

3.22

ER-Series (Short Style)

1.995 DIA. +.000 –.005

A =

.19

7

8

.015 RELIEF

NOTE: For minimum

projection on runner/ part, alter the bushing face (See figures 1 through 3 below).

1.000 DIA.

R

.25 DIA.

.12 DIA.

.44

.50

.340

ENLARGED VIEW AS SUPPLIED

SSBT4407ER2

SSBT0407ER2

Design Guidelines for Altering ER-Series Straight-Shot Hot Sprue Bushings (Long and Short Styles)

FIG. 1

FIG. 2

.25

.25

.25 MIN.

.25 MIN.

RUNNER

PART

.25

For minimum projection on runner/part, machine the runner profile or part contour .25 inch deep into the bushing face at the centerline of the orifice (See Figures 1 and 2). When gating into a flat surface, remove the .25 inch extra stock allowance on the bushing face (See Figure 3). However, do not weaken the bushing face by exceeding the .25 inch dimension. The A dimension can be altered by removing stock from the front face of the 2.00 diameter bushing shoulder.

.25 MIN.

FIG. 3

RUNNER/PART

U.S. 800-626-6653 n Canada 800-387-6600 n dme.net n store.dme.net

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