© National Instruments
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4-3
NI sbRIO-9651 System on Module Carrier Board Design Guide
Table 4-3 provides an example standoff height calculation using a Molex 45970-4130 mating
connector.
NI Custom Standoffs
NI offers a custom standoff that is an exact fit with the recommended or other compatible 7-mm
stack height mating connectors listed in Table 4-1. This custom M3 × 7.15 mm (0.281 in.) is
made from 4.5 mm (0.177 in.) stainless steel hex stock and includes a nylon threadlock patch.
The external threads extend 4.78 mm (0.188 in.) and the internal threads are 5 mm (0.197 in.)
deep. Table 4-4 lists orderable quantities of this custom standoff.
NI recommends that you use stainless steel fasteners for good corrosion resistance and strength.
Tighten M3 fasteners to a torque of 0.76 N · m (6.70 lb · in), unless otherwise noted or required
by your specific design constraints.
Table 4-3.
Example Connector Configuration and Calculated Standoff Height
Component
Manufacturer,
Part Number
Height
J1 connector on the sbRIO-9651 SOM
Molex, 45971-4185
5.00 mm (0.197 in.)
Mating connector
Molex, 45970-4130
2.00 mm (0.079 in.)
Required additional standoff height
—
0.15 mm (0.006 in.)
Total calculated standoff height
—
7.15 mm (0.281 in.)
Table 4-4.
Custom M3 × 7.15 mm (0.2
8
1 in.) Standoff Kits
Quantity
Manufacturer, Part Number
20
NI, 157543-020
500
NI, 157543-500