366 New brush material meets all design requirements and brush wear was consistent with wear observed  during engineering testing. An estimated brush loss of 17% of brush usable material was observed. 

Table 3. Brush Wear 

New Brush A1 A2 B1 B2  Percent Reduction ~14% ~14% ~14% ~17% 

Table 4. UBGM vs BGM Performance Comparison 

Successful qualification was a dire ct result of the trade study development. The Six-Sigma process and  trade study identified the driving re quirements. DC brush gear motor pe rformance was improved resulting  in approximately 11 N-m (100 in-lb) torque increase at the output. The upgraded gear head assembly is a robust design with lower drag, non-binding operation at all temperatures, and non-galling material combinations. The risk of damage to hardware during assembly was lowered due to design simplification. The new qualified DC brush gear motor is a robust design capable of handling all environmental conditions with consistent predictable performance.   Test Description Units Max Min Max Min Max Min Max Min Max Min Max Min Drag torque Tooling Only (Dynamic torque @ 450 RPM) N-cm (in-oz) Drag torque Tooling only (torque to start) N-cm (in-oz) Drag torque GearBox (Dynamic torque @ 450 RPM) N-cm (in-oz) Drag torque GearBox (Torque to start) N-cm (in-oz) Tool Drag Removed Drag torque GearBox (Dynamic torque @ 450 RPM) N-cm (in-oz) Drag torque GearBox (Torque to start) N-cm (in-oz) Test Description Units Max Min Max Min Max Min Max Min Max Min Max Min Drag torque Motor (Dynamic torque @ 450 RPM) N-cm (in-oz) Drag torque GearBox (Dynamic torque @ 450 RPM) N-cm (in-oz) Drag torque Motor (Torque to start) N-cm (in-oz) Drag torque GearBox (Torque to start) N-cm (in-oz) No load speed (Motor w ith 6.0 V) rpm 588 571 549 505 572 563 440 405 480 455 515 470 No load current (Motor w ith 6.0V) amps 0.081 0.080 0.077 0.072 0.065 0.062 0.100 0.095 0.098 0.095 0.078 0.075 Time to rotate 90 degrees (Motor and GearBox w ith 6.6 V) sec 78.5 75.5 82 76.75 78.75 74.25 68.00 65.00 74.00 72.00 No load speed (Motor and GearBox w ith 6.6 V) rpm 0.19 0.20 0.18 0.20 0.19 0.20 0.221 0.231 0.203 0.208 No load current (Motor and GearBox w ith 6.6 V) amps 0.101 0.099 0.093 0.084 0.084 0.078 0.080 0.070 0.086 0.083 Stall Torque (Motor w ith 6.0 V)N-c m (in-oz)3.2  (4.5)3.2  (4.5)2.4  (3.4)2.3  (3.3)2.0  (2.9)1.9  (2.7)2.1  (3.0)1.6  (2.2)1.2  (1.7)0.78  (1.1)1.1  (1.6)0.78  (1.1) Stall Torque (Motor and GearBox w ith 6.6 V)N-m (in-lb)48.0  (425)47.5  (420)50.6  (448)49.5  (438)48.0  (425)47.5  (420)36.2  (320)33.9  (300)29.0  (257)28.8  (255)33.1  (293)29.9  (265) Tested at 6.0 V0.31 (0.44) 0.18 (0.26) 0.16 (0.23) 0.01 (0.02)0.04 (0.06) 0.02 (0.03) 0.00 (0.00)0.06 (0.09) 0.06 (0.08) 0.08 (0.11)0.06 (0.08) 0.01 (0.02) 0.00 (0.00)0.18 (0.26)0.04 (0.05) 0.05 (0.07) 0.11 (0.15)0.06 (0.08)UBGM BGM 0.15 (0.21) 0.18 (0.25) 0.37 (0.52)-50°C +23°C +80°C -50°C +23°C +80°C 0.04 (0.05) 0.05 (0.07) 0.06 (0.08)0.15 (0.21) 0.18 (0.25)0.06 (0.09)0.06 (0.08) 0.13 (0.18)0.07 (0.10) 0.06 (0.09) 0.07 (0.10) 0.007 (0.01) UBGM BGM -50°C +23°C +80°C -50°C +23°C +80°C0.22 (0.31) 0.01 (0.02) 0.01 (0.02) 0.01 (0.02)0.99 (1.40) 0.16 (0 .2 3) 1.31 (1.85) 0.01 (0.02)0.99 (1.40) 0.01 (0.02)1.31 (1.85) 0.00 (0.00)0.81 (1.15) 0.06 (0.09) 2.8 (4.0) 0.01 (0.02)0.78 (1.10)0.07 (0.10) 2.8 (4.0) 0.007 (0.01)0.99 (1.40)0.02 (0.03)1.31 (1.85) 0.00 (0.00)0.85 (1.20) 0.22 (0.31) 2.8 (4.0) NASA/CP-2010-216272