VEX Robotics Motor Data - BaneBots RS-775 18V


Note: Published Specifications were taken from the BaneBots website and are current as of December 10, 2015. Experimental tests were performed using new motors that were purchased during the summer of 2015. Specifications were scaled down from nominal 18V to 12V (VEX tests were performed at 12V).

  Published Specification Experimental Data
Free Speed (RPM) 13000 13050
Free Current (A) 1.8 2.7
Maximum Power (W) 265 246
Stall Torque (N · m) 0.78 0.72
Stall Current (A) 86.7 97
The "Down-Up" Test: Why VEX provides the most accurate motor data possible

Learn more about using DC motors and motor curves to design robots





 

VEX Robotics Motor Data - BaneBots RS-775 18V

 
 

Note: Published Specifications were taken from the BaneBots website and are current as of December 10, 2015. Experimental tests were performed using new motors that were purchased during the summer of 2015. Specifications were scaled down from nominal 18V to 12V (VEX tests were performed at 12V).

 
  Published Specification Experimental Data
Free Speed (RPM) 13000 13050
Free Current (A) 1.8 2.7
Maximum Power (W) 265 246
Stall Torque (N · m) 0.78 0.72
Stall Current (A) 86.7 97
 
 

The "Down-Up" Dyno Test

VEX Robotics motor curves were developed experimentally using a “down-up” dyno test.

1. A motor is spun at free speed
2. A brake is slowly applied (linearly increasing in torque over time), bringing the motor down to a predetermined RPM
3. The brake is slowly released and the motor is allowed to return to its free speed

A variety of data, such as output speed, output torque, current draw, and power input/output, is taken throughout this test. The “down” (brake applied) side is then averaged with the “up” (brake released) side.

Why "Down-Up"?

The mechanics of a dyno test are crucial to developing and publishing accurate motor specifications. When a motor is spinning at free speed while attached to a dyno drum, the system contains a high amount of rotational inertia. This inertia complements the motor’s own output, creating a false reading for peak output power that can be higher than the motor’s actual performance.

However, manufacturers do not always adjust for inertia cancellation when measuring their motor’s performance, and spec sheets rarely detail the circumstances under which their information was derived.

By testing and averaging both the “down” (inertia helping the motor) and “up” (inertia resisting the motor) sides, this method is the best way to represent a motor’s true capacity.

Click to Expand Motor Curve Data

Click to download motor curve data (.CSV)

Speed (RPM)
Torque (N·m)
Current (A)
Supplied Power (W)
Output Power (W)
Efficiency (%)
Power Dissipation (W)
0
0.72
97.131
1165.572
0
0
1165.572
130.468
0.7128
96.16
1153.92
9.739
0.844
1144.181
260.936
0.7056
95.188
1142.256
19.281
1.688
1122.975
391.404
0.6984
94.217
1130.604
28.626
2.532
1101.978
521.873
0.6912
93.246
1118.952
37.774
3.376
1081.178
652.341
0.684
92.274
1107.288
46.726
4.22
1060.562
782.809
0.6768
91.303
1095.636
55.481
5.064
1040.155
913.277
0.6696
90.332
1083.984
64.039
5.908
1019.945
1043.745
0.6624
89.361
1072.332
72.401
6.752
999.931
1174.213
0.6552
88.389
1060.668
80.566
7.596
980.102
1304.682
0.648
87.418
1049.016
88.534
8.44
960.482
1435.15
0.6408
86.447
1037.364
96.305
9.284
941.059
1565.618
0.6336
85.475
1025.7
103.879
10.128
921.821
1696.086
0.6264
84.504
1014.048
111.257
10.972
902.791
1826.554
0.6192
83.533
1002.396
118.438
11.815
883.958
1957.022
0.612
82.561
990.732
125.423
12.66
865.309
2087.49
0.6048
81.59
979.08
132.21
13.503
846.87
2217.959
0.5976
80.619
967.428
138.801
14.347
828.627
2348.427
0.5904
79.647
955.764
145.195
15.192
810.569

Speed (RPM)
Torque (N·m)
Current (A)
Supplied Power (W)
Output Power (W)
Efficiency (%)
Power Dissipation (W)
2478.895
0.5832
78.676
944.112
151.392
16.035
792.72
2609.363
0.576
77.705
932.46
157.393
16.879
775.067
2739.831
0.5688
76.733
920.796
163.197
17.723
757.599
2870.299
0.5616
75.762
909.144
168.804
18.567
740.34
3000.767
0.5544
74.791
897.492
174.214
19.411
723.278
3131.236
0.5472
73.82
885.84
179.428
20.255
706.412
3261.704
0.54
72.848
874.176
184.445
21.099
689.731
3392.172
0.5328
71.877
862.524
189.265
21.943
673.259
3522.64
0.5256
70.906
850.872
193.889
22.787
656.983
3653.108
0.5184
69.934
839.208
198.315
23.631
640.893
3783.576
0.5112
68.963
827.556
202.545
24.475
625.011
3914.045
0.504
67.992
815.904
206.578
25.319
609.326
4044.513
0.4968
67.02
804.24
210.415
26.163
593.825
4174.981
0.4896
66.049
792.588
214.055
27.007
578.533
4305.449
0.4824
65.078
780.936
217.498
27.851
563.438
4435.917
0.4752
64.106
769.272
220.744
28.695
548.528
4566.385
0.468
63.135
757.62
223.793
29.539
533.827
4696.853
0.4608
62.164
745.968
226.646
30.383
519.322
4827.322
0.4536
61.193
734.316
229.302
31.227
505.014
4957.79
0.4464
60.221
722.652
231.761
32.071
490.891
5088.258
0.4392
59.25
711
234.024
32.915
476.976
5218.726
0.432
58.279
699.348
236.09
33.759
463.258
5349.194
0.4248
57.307
687.684
237.959
34.603
449.725
5479.662
0.4176
56.336
676.032
239.631
35.447
436.401
5610.13
0.4104
55.365
664.38
241.106
36.29
423.274
5740.599
0.4032
54.393
652.716
242.385
37.135
410.331
5871.067
0.396
53.422
641.064
243.467
37.979
397.597
6001.535
0.3888
52.451
629.412
244.353
38.822
385.059
6132.003
0.3816
51.479
617.748
245.041
39.667
372.707
6262.471
0.3744
50.508
606.096
245.533
40.511
360.563
6392.939
0.3672
49.537
594.444
245.828
41.354
348.616
6523.408
0.36
48.566
582.792
245.927
42.198
336.865
6653.876
0.3528
47.594
571.128
245.828
43.043
325.3
6784.344
0.3456
46.623
559.476
245.533
43.886
313.943
6914.812
0.3384
45.652
547.824
245.041
44.73
302.783
7045.28
0.3312
44.68
536.16
244.353
45.575
291.807
7175.748
0.324
43.709
524.508
243.467
46.418
281.041
7306.216
0.3168
42.738
512.856
242.385
47.262
270.471
7436.685
0.3096
41.766
501.192
241.107
48.107
260.085

Speed (RPM)
Torque (N·m)
Current (A)
Supplied Power (W)
Output Power (W)
Efficiency (%)
Power Dissipation (W)
7567.153
0.3024
40.795
489.54
239.631
48.95
249.909
7697.621
0.2952
39.824
477.888
237.959
49.794
239.929
7828.089
0.288
38.852
466.224
236.09
50.639
230.134
7958.557
0.2808
37.881
454.572
234.024
51.482
220.548
8089.025
0.2736
36.91
442.92
231.761
52.326
211.159
8219.493
0.2664
35.938
431.256
229.302
53.171
201.954
8349.962
0.2592
34.967
419.604
226.646
54.014
192.958
8480.43
0.252
33.996
407.952
223.793
54.858
184.159
8610.898
0.2448
33.025
396.3
220.744
55.701
175.556
8741.366
0.2376
32.053
384.636
217.498
56.546
167.138
8871.834
0.2304
31.082
372.984
214.055
57.39
158.929
9002.302
0.2232
30.111
361.332
210.415
58.233
150.917
9132.771
0.216
29.139
349.668
206.578
59.078
143.09
9263.239
0.2088
28.168
338.016
202.545
59.922
135.471
9393.707
0.2016
27.197
326.364
198.315
60.765
128.049
9524.175
0.1944
26.225
314.7
193.889
61.611
120.811
9654.643
0.1872
25.254
303.048
189.265
62.454
113.783
9785.111
0.18
24.283
291.396
184.445
63.297
106.951
9915.579
0.1728
23.311
279.732
179.428
64.143
100.304
10046.048
0.1656
22.34
268.08
174.214
64.986
93.866
10176.516
0.1584
21.369
256.428
168.804
65.829
87.624
10306.984
0.1512
20.398
244.776
163.197
66.672
81.579
10437.452
0.144
19.426
233.112
157.393
67.518
75.719
10567.92
0.1368
18.455
221.46
151.392
68.361
70.068
10698.388
0.1296
17.484
209.808
145.195
69.204
64.613
10828.856
0.1224
16.512
198.144
138.801
70.051
59.343
10959.325
0.1152
15.541
186.492
132.21
70.893
54.282
11089.793
0.108
14.57
174.84
125.423
71.736
49.417
11220.261
0.1008
13.598
163.176
118.438
72.583
44.738
11350.729
0.0936
12.627
151.524
111.257
73.425
40.267
11481.197
0.0864
11.656
139.872
103.879
74.267
35.993
11611.665
0.0792
10.684
128.208
96.305
75.116
31.903
11742.134
0.072
9.713
116.556
88.534
75.958
28.022
11872.602
0.0648
8.742
104.904
80.566
76.8
24.338
12003.07
0.0576
7.77
93.24
72.401
77.65
20.839
12133.538
0.0504
6.799
81.588
64.039
78.491
17.549
12264.006
0.0432
5.828
69.936
55.481
79.331
14.455
12394.474
0.036
4.857
58.284
46.726
80.17
11.558
12524.942
0.0288
3.885
46.62
37.774
81.025
8.846

Speed (RPM)
Torque (N·m)
Current (A)
Supplied Power (W)
Output Power (W)
Efficiency (%)
Power Dissipation (W)
12655.411
0.0216
2.914
34.968
28.626
81.863
6.342
12785.879
0.0144
1.943
23.316
19.281
82.694
4.035
12916.347
0.0072
0.971
11.652
9.739
83.582
1.913
13046.815
0
0
0
0
0
0

Click to Collapse Motor Curve Data

Click to Expand 3 Minute Peak Power Test Data

Click to download peak power test data (.CSV)

Time (s)
Current (A)
Power Out (W)
0.001
55.81
261.099
0.373
55.39
258.578
0.75
54.82
254.143
1.155
53.42
246.098
1.535
52.01
245.044
1.918
50.95
231.533
2.267
47.12
226.262
2.618
47.1
225.339
2.965
47
221.287
3.315
46.65
224.624
3.664
47.75
224.278

Time
Current (A)
Power Out (W)
4.013
47.27
217.649
4.389
46.58
220.675
4.74
45.93
217.771
5.088
45.31
215.127
5.437
44.77
208.357
5.787
44.39
212.143
6.135
44.46
211.043
6.512
44.38
209.423
6.86
44.08
206.671
7.21
43.7
208.904
7.558
43.51
210.297
7.934
43.75
206.512
8.284
42.81
206.958
8.633
42.6
206.341
8.984
42.31
203.648
9.332
41.93
206.99
9.682
41.62
206.214
10.057
40.75
206.958
10.407
41.34
202.624
10.757
41.08
203.617
11.105
40.71
203.46
11.454
40.8
206.245
11.804
40.99
204.537
12.181
40.72
202.006
12.529
40.74
202.037
12.88
40.31
199.408
13.228
40.29
197.275
13.577
38.85
190.653
13.927
38.24
195.805
14.277
38.94
196.458
14.636
39.94
195.084
14.992
39.35
193.164
15.351
38.95
198.382
15.699
39.24
194.633
16.049
38.18
193.669
16.424
38.78
193.372
16.774
38.75
198.291
17.124
39.32
197.214
17.472
39.23
194.494

Time
Current (A)
Power Out (W)
17.821
39.54
195.535
18.197
39.65
193.342
18.545
39.36
192.217
18.896
38.87
191.774
19.245
38.43
193.045
19.594
38.41
195.445
19.944
38.96
189.054
20.32
37.92
190.947
20.669
37.33
190.736
21.017
37.69
191.859
21.367
38.18
192.691
21.717
38.22
190.473
22.066
38.1
190.114
22.442
38.49
189.141
22.791
38.36
191.715
23.14
38.26
190.619
23.489
38.17
190.026
23.84
38.22
190.59
24.188
38.03
192.691
24.565
37.99
189.909
24.967
37.74
191.418
25.333
37.6
186.334
25.694
37.38
187.549
26.042
37.19
189.968
26.392
37.13
189.851
26.768
36.88
188.461
27.118
37.22
186.506
27.521
37.11
185.882
27.868
37.3
189.141
28.218
37.39
188.519
28.567
37.34
188.432
28.917
37.25
185.002
29.265
36.94
186.592
29.625
36.92
187.983
30.009
37.26
187.215
30.368
37.23
184.974
30.718
36.93
186.563
31.093
36.86
183.868
31.443
36.4
183.131

Time
Current (A)
Power Out (W)
31.844
36.42
183.529
32.194
36.59
181.172
32.543
36.42
180.296
32.893
36.39
181.685
33.241
36.33
181.685
33.591
36.17
178.991
33.951
35.94
179.046
34.306
35.95
180.435
34.666
36.05
179.727
35.016
36.38
181.088
35.417
36.47
178.338
35.767
36.24
176.269
36.116
36.1
177.031
36.464
36.17
180.352
36.842
35.96
178.338
37.191
36.04
180.435
37.54
36.32
177.058
37.889
36.15
176.296
Time (s)
Current (A)
Power Out (W)
38.239
36.23
178.146
38.587
36.08
177.031
38.938
36.16
178.749
39.314
36.26
178.146
39.662
36.02
175.507
40.011
36.09
176.431
40.361
36.16
177.112
40.711
36.31
176.377
41.06
35.99
175.507
41.435
36.06
177.249
41.784
36.12
177.876

Time
Current (A)
Power Out (W)
42.135
35.97
177.004
42.537
36.08
174.307
42.887
36.32
172.733
43.235
36.03
176.976
43.585
35.8
175.372
43.935
35.77
173.6
44.338
35.62
174.441
44.686
35.61
171.373
45.037
35.35
172.972
45.411
35.35
174.307
45.761
35.4
172.945
46.111
35.28
172.892
46.46
35.01
171.452
46.808
35.14
170.903
47.158
35.19
174.093
47.535
35.15
174.334
47.883
35.27
173.626
48.233
35.36
173.439
48.582
35.26
170.196
48.932
35.17
172.265
49.28
35.07
170.666
49.63
35.05
170.274
50.006
34.82
169.986
50.356
34.75
171.399
50.741
34.76
172.919
51.124
35.05
171.373
51.485
34.59
168.73
51.887
34.79
168.205
52.235
34.76
169.358
52.584
34.47
170.274
52.96
34.53
169.228
53.311
34.31
169.776
53.659
34.43
166.561
54.009
34.53
168.179
54.358
34.4
169.567
54.706
34.66
168.73
55.057
34.45
165.779
55.434
34.07
167.627
55.836
34.19
167.267

Time
Current (A)
Power Out (W)
56.202
33.97
166.766
56.561
34.09
167.421
56.91
34.18
163.187
57.27
33.78
164.195
57.623
33.76
167.576
57.985
33.92
163.463
58.333
34
163.488
58.683
34.18
165.328
59.032
34.1
165.856
59.41
33.81
165.932
59.81
33.68
164.018
60.176
33.61
163.187
60.537
33.78
164.902
60.896
33.92
164.8
61.291
33.94
162.682
61.639
33.96
162.807
62.004
34.02
165.557
62.392
34.01
165.507
62.741
33.83
165.278
63.144
33.92
164.018
63.492
33.86
162.732
63.841
33.92
165.227
64.19
34.01
163.589
64.54
33.92
163.212
64.899
33.77
161.802
65.282
33.84
164.043
65.641
33.73
166.92
66.018
34
167.421
66.405
34
168.153
66.787
34.34
164.043
67.145
34.23
163.766
67.494
33.85
164.521
67.844
33.81
167.524
68.219
34.08
164.902
68.569
33.86
162.532
68.917
33.77
163.842
69.267
33.41
165.634
69.616
34.02
167.421
69.991
33.85
163.413

Time
Current (A)
Power Out (W)
70.341
34.09
162.482
70.689
33.65
164.825
71.039
33.93
166.06
71.388
33.81
166.664
71.764
33.92
167.344
72.113
34.03
166.264
72.462
34.21
164.521
72.813
34.15
167.627
73.161
34.11
165.932
73.511
33.89
166.162
73.86
33.81
163.187
74.236
33.81
162.582
74.585
33.81
163.968
74.935
33.38
164.094
75.283
33.51
164.623
75.633
33.59
162.682
76.009
33.84
165.43
76.359
33.39
163.741
Time (s)
Current (A)
Power Out (W)
44.325
27.99
98.214
44.675
28.38
83.914
45.023
38.25
100.229
45.391
39.96
73.548
45.748
50.53
57.467
46.099
97.25
20.492
46.447
20
11.4
46.796
19.47
22.846
47.156
18.45
31.17
47.512
17.71
14.705
47.872
17.46
32.219

Time
Current (A)
Power Out (W)
48.257
17.21
8.933
48.613
19.98
28.857
48.972
19.99
20.633
49.321
20.06
18.962
49.67
20.55
24.584
50.031
23.59
28.586
50.413
24.84
20.288
50.774
25.76
18.27
51.147
43.07
12.86
51.496
75.42
1.851
51.846
8.44
12.098
52.194
8.82
0.753
52.544
10.15
10.571
52.894
11.55
2.809
53.268
11.62
1.824
53.632
13.58
0.361
54.022
50.88
0.157
54.388
0
0
54.746
0
0
55.123
0
0
55.471
0
0
55.818
0
0
56.167
0
0
56.557
0
0
56.908
0
0
57.283
0
0
57.661
0
0
58.022
0
0
58.37
0
0
58.718
0
0
59.08
0
0
59.433
0
0
59.807
0
0
60.198
0
0
60.546
0
0
60.895
0
0
61.245
0
0
61.634
0
0
62.036
0
0

Time
Current (A)
Power Out (W)
62.384
0
0
62.738
0
0
63.097
0
0
63.46
0
0
63.839
0
0
64.199
0
0
64.548
0
0
64.897
0
0
65.287
0
0
65.679
0
0

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