1. Bulk Molding Compounds, Inc.
‘Complete Composite Solutions’

2. BMC Injection- Molded Motor Brackets

3. BMC vs. Die Cast Metals ADVANTAGES
Reduced Cycle Times / Reduced Manufacturing Cost
Thermal / Dimensional Stability
Noise Reduction
Weight Reduction
Elimination of Costly Secondary Machining Operations
Lower Tooling Costs / Longer Tool Life
Greater Design Freedom
= 30-50% Cost Savings over Die-Cast Metal

4. Thermal / Dimensional Stability
RIGIDITY AT ELEVATED TEMPERATURES
BMC Composites vs. Engineering Thermosets

5. Thermal / Dimensional Stability
BMCs offer significant acoustical insulation over metals
Automotive valve cover conversion from aluminum to BMC
25% Reduction in Valve-train noise in BMC !

6. Part Weight Reduction

7. Lower Specific-Gravity with BMC
Part Weight Reduction
Lower Specific-Gravity with BMC
BMC Polyester : 1.7 – 2.05s.g.
Die-Cast Aluminum : 2.6s.g.
Die-Cast Zinc : 6.9s.g.
Reduction In Assembly / Unit Weight
Lower Raw Material Content $
Reduction in Shipping Weight / Cost $

8. No Secondary Machining
BMC Parts molded GATE FREE. No Secondary Gate Removal
No material overflows required for BMC. No secondary trim-die operation required
Critical dimensions / tolerances typically held as-molded. No secondary machining operations required.
Package At Press!

9. Tooling Friendly
BMC Polyesters are very “tooling-friendly” offering the following advantages over metals:
4-5 Times Longer Mold Life
Higher Cavitations
Significantly lower PM & Repair Costs
Allows for use of more complex moving actions (Slides etc.)
Allows for use of manifold systems for material delivery to cavities

10. Greater Design Freedom
The flow characteristics and related moldability of BMCs allows for the formation of more complex part geometries.
This gives the part designer increased freedom to:
Incorporate the net-shapes required to optimize the part / assembly design
Reduce the number of components through consolidation of parts

11. Motor Bracket Configurations
Commutator End Brackets / End Bells
Fan End Brackets
Clamshell Motors
Motor End Plates
“Cup” Style Motor Housings
Fan / Diffuser End Caps
Brush Plates
Brush Cartridge Housings

12. Commutator End Bracket / End Bell
Integrated Brush Box Features
As-Molded Bearing Bore, Brush Boxes & Field Pads

13. Fan End Brackets Integrated Airflow Features
As-Molded Bearing Bore & Field Pads
Mounting Points Suitable for Motor Assembly

14. Clamshell Motor Housings
As-Molded Bearing Bore
Advantages in Small Hand- Held Applications
Weight Reduction
Noise / Vibration Reduction
Ground-Path Insulation

15. Motor End Plates As-Molded Bearing Bore
Weight Reduction on Large Motor Configurations

16. “Cup” Style Motor Housings
Reduced Number of Components in Assembly
More Consistent Motor Alignment
As-Molded Bearing Bore, Brush Boxes & Field Pads
Integrated Airflow Features

17. Fan / Diffuser End Caps
* Accommodates the formation of more complex / efficient airflow geometries

18. Brush Plates / Cartridge Housings
Superior Properties over Thermoplastics

19. BMC Motor Bracket Materials
BMC Materials currently supplied into motor bracket applications:
BMC 400
BMC 620
BMC 1412
T40-(18)
T40-(20)
T40-(25)
BMCI can custom-formulate materials as-necessary to meet specific applications.

20. Case Study #1 Commutator End Bracket Conversion
Aluminum
BMC
Material Cost / Part:
Molding Cost / Part:
Secondary Gate Trimming:
Secondary Machining: 3%
Total Cost / Part:
$.19
$.281
$.01
$.035
$.015
$.531
$.14
$.225 -
$.011
$.376
30% SAVINGS

21. Case Study #2 Commutator End Bell Conversion/Redesign
Brush Boxes incorporated into BMC part as 1-Piece Design
Aluminum
BMC
Material Cost / Part:
Molding Cost / Part:
Secondary Gate Trimming:
Secondary Machining: 3%
Brush Plate (2nd Part):
Total Cost / Part:
$.08
$.22
$.01
$.035
$.001
$.217
$.563
$.133
$.23 -
$.011
$.374
34% SAVINGS

22. Mounting Hardware for BMCs
Self-Tapping Screws
Thread-Cutting Never Thread-Forming
“BT”-Style or “Type-23” Style recommended
High-Low thread preferred
Hole diameter +.002” p/s over root-diameter of screw
Minimum thread engagement 2 ½ X screw diameter
Hole depth 125% to 150% of screw engagement depth
Mounting boss diameter minimum 2X major screw diameter

23. Design Considerations for BMC
Minimum Recommended Wall Stock .070”
Recommended Nominal Wall Stock .100” ”
Minimum draft 1-degree P/S (Excluding Bores & Brush Boxes)
Consistency of Wall stock
Core-out Thick Sections Wherever Possible
Fillet Radii Wherever Possible
“Line-of-Draw Features Wherever Possible

24. BMC offers cost savings without sacrifice.
The BMC Advantage
Faster Cycling
Longer Tooling Life
No Costly Secondary Machining
Weight Reduction
Noise Reduction
Dimensional Stability
Design Versatility
BMC offers cost savings without sacrifice.