This thread is for people to post specs of the 2007 motors.
New motors: the two banebots motors. spec spec spec!
I’m off to work spec-ing them up, will post.
Banebots RS-540 motor
Nominal v: 12v, No Load RPM: 16800, Stall Current: 42A
Kt: 0.94 oz-in/A, Kv: 1400 rpm/V, Efficiency: 71%
more info here
Motor Specifications
Performance
Operating v : 4.5v - 12v
Nominal v : 12v
No Load RPM : 16800
No Load A : 1A
Stall Torque : 39.48 oz-in 278.8 mN-m
Stall Current : 42A
Kt : 0.94 oz-in/A 6.6 mN-m/A
Kv : 1400 rpm/V
Efficiency : 71%
RPM - Peak Eff : 14525
Current - Peak Eff : 6.6A
Physical
Weight : 5.4 oz (153g)
Length - for motor : 1.97 in (50mm)
Diameter : 1.41 in (35.8mm)
ShaftDiameter : 0.12 in (3.2mm)
Shaft Length : 0.3 in (7.6mm)
Mounting Screws (2) M3
Banebots has added a linkon their home page for FIRST teams, which goes straight to the parts included in the KOP.
Looking at <R27> in section 8.3.4 leads me to believe that once again we have a different fisher price motor to spec out this year, unless its the same as the one we had two years ago because it says
If it is the same as 2005 does anyone still have the specs laying around?
We are back at it again. It does not look like FIRST has published the FP motor specs this year. I have searched through all my previous posts (back to 2002) and checked all the FP motor specs I have published in the past. This year’s motor is different from the 2002, 2003, 2004, 2005, and 2006 motors.
One thing is certain: the motor is made by Johnson Electric. That is good news since I should be able to get the data from JE this week. Our gear on the motor is 19 teeth, but I do not know if everyone’s is the same. I will post to this thread when I get the motor data.
Does anyone know the motor specs on the Keyang Motor?
Are we going to get power/rpm/ current curves on these RS-540 motors as we have in the past with new motors in the kit, or do we have to estimate it ourselves?
I think the information you’re looking for is available on the Banebots website.
The gearmotors specs. can be found here: http://www.banebots.com/pc/MP-36XXX-540/MP-36064-540
The motor specs. without the gearbox are here:
http://www.banebots.com/p/M2-RS540-120
They don’t have the curves themselves, but there’s at least some information available.
There is some info on the banebots site, but not the actual power information I’d like. Of course, if I get a little more ambitious, I can calculate a good approximation of what I’m looking for. I’d like to know the maximum power in watts or horsepower that the motor produces.
Power (output) it torque times speed. Well… Watts = N-m * radians/sec. or = N-m * RPM/602pi.
RPM decreases linearly from no load speed at … no load, to zero at stall. Thus, max power is always at half the no load speed.
Thus, Max power for the RS540 is ~122W.
The RS 545 is 108W.
This is, of course, highly approximate. But you really should be designing below Max power anyways, right?
This is the Fisher-Price 00968-9012, one of the RS-550 Johnson motors allowed (but not supplied to all teams) in 2006. The 9003 (largely equivalent, and also supplied to some teams in 2006) is not legal. FIRST’s 2006 spec sheet is here. To identify the number of gear teeth on the motor pinion, without disassembling it, examine the injection-moulded plastic gear housing, and look for a small number 19 (or 16, or 20) on the side. 188 received 19-tooth-compatible gear reducers.
Thanks for doing the calculation for me. Yes, we design for well below peak power (motor running maybe 75-80 % of no-load rpm) except for an occasional few seconds of “extreme” operation near its power peak. Most of our motors will have a very short service life if run at their power peak.
Would it be legal to buy 2 extra 56mm Planetary Gearbox, 12:1? The same one included in the KOP?
Also, how much do these gearboxes weigh?
Perfectly legal. It’s COTS item offered by BaneBots and it costs less than $400. Well. Perfectly legal as long as you still stay under your $3500 limit.
EDIT: I weighed them in at around 2.5 lbs apiece last night. The only scale I had was a bit nutty, so YMMV by +/- .25 lbs.
Thanks! Does that weight include the CIM? If not what is the mass of the CIM motors?
They’re about 2.5 lbs. without the motors. The motors themselves are about another 2.5 lbs. each, as I recall.
Thanks! I am just surprised they didn’t give the dimensions and weight of the gearbox.
I calculated the theoretical speed/torque/power curve for the RS-540. I would post a graph here, but right now all i have available is open office.org which isn’t very good at drawing the graph scales the way i want it to. I can export it to xls or csv or something though.
It may not be exact but should be pretty close.
Note: Calculated @12V
Speed(rpm) Torque (mNm) Power(watts)
0 277.20000 0
100 275.55000 2.89
200 273.90000 5.74
300 272.25000 8.55
400 270.60000 11.33
500 268.95000 14.08
600 267.30000 16.79
700 265.65000 19.47
800 264.00000 22.12
900 262.35000 24.73
1000 260.70000 27.3
1100 259.05000 29.84
1200 257.40000 32.35
1300 255.75000 34.82
1400 254.10000 37.25
1500 252.45000 39.65
1600 250.80000 42.02
1700 249.15000 44.35
1800 247.50000 46.65
1900 245.85000 48.92
2000 244.20000 51.15
2100 242.55000 53.34
2200 240.90000 55.5
2300 239.25000 57.62
2400 237.60000 59.72
2500 235.95000 61.77
2600 234.30000 63.79
2700 232.65000 65.78
2800 231.00000 67.73
2900 229.35000 69.65
3000 227.70000 71.53
3100 226.05000 73.38
3200 224.40000 75.2
3300 222.75000 76.98
3400 221.10000 78.72
3500 219.45000 80.43
3600 217.80000 82.11
3700 216.15000 83.75
3800 214.50000 85.36
3900 212.85000 86.93
4000 211.20000 88.47
4100 209.55000 89.97
4200 207.90000 91.44
4300 206.25000 92.87
4400 204.60000 94.27
4500 202.95000 95.64
4600 201.30000 96.97
4700 199.65000 98.26
4800 198.00000 99.53
4900 196.35000 100.75
5000 194.70000 101.94
5100 193.05000 103.1
5200 191.40000 104.23
5300 189.75000 105.31
5400 188.10000 106.37
5500 186.45000 107.39
5600 184.80000 108.37
5700 183.15000 109.32
5800 181.50000 110.24
5900 179.85000 111.12
6000 178.20000 111.97
6100 176.55000 112.78
6200 174.90000 113.56
6300 173.25000 114.3
6400 171.60000 115.01
6500 169.95000 115.68
6600 168.30000 116.32
6700 166.65000 116.93
6800 165.00000 117.5
6900 163.35000 118.03
7000 161.70000 118.53
7100 160.05000 119
7200 158.40000 119.43
7300 156.75000 119.83
7400 155.10000 120.19
7500 153.45000 120.52
7600 151.80000 120.81
7700 150.15000 121.07
7800 148.50000 121.3
7900 146.85000 121.49
8000 145.20000 121.64
8100 143.55000 121.76
8200 141.90000 121.85
8300 140.25000 121.9
8400 138.60000 121.92
8500 136.95000 121.9
8600 135.30000 121.85
8700 133.65000 121.76
8800 132.00000 121.64
8900 130.35000 121.49
9000 128.70000 121.3
9100 127.05000 121.07
9200 125.40000 120.81
9300 123.75000 120.52
9400 122.10000 120.19
9500 120.45000 119.83
9600 118.80000 119.43
9700 117.15000 119
9800 115.50000 118.53
9900 113.85000 118.03
10000 112.20000 117.5
10100 110.55000 116.93
10200 108.90000 116.32
10300 107.25000 115.68
10400 105.60000 115.01
10500 103.95000 114.3
10600 102.30000 113.56
10700 100.65000 112.78
10800 99.00000 111.97
10900 97.35000 111.12
11000 95.70000 110.24
11100 94.05000 109.32
11200 92.40000 108.37
11300 90.75000 107.39
11400 89.10000 106.37
11500 87.45000 105.31
11600 85.80000 104.23
11700 84.15000 103.1
11800 82.50000 101.94
11900 80.85000 100.75
12000 79.20000 99.53
12100 77.55000 98.26
12200 75.90000 96.97
12300 74.25000 95.64
12400 72.60000 94.27
12500 70.95000 92.87
12600 69.30000 91.44
12700 67.65000 89.97
12800 66.00000 88.47
12900 64.35000 86.93
13000 62.70000 85.36
13100 61.05000 83.75
13200 59.40000 82.11
13300 57.75000 80.43
13400 56.10000 78.72
13500 54.45000 76.98
13600 52.80000 75.2
13700 51.15000 73.38
13800 49.50000 71.53
13900 47.85000 69.65
14000 46.20000 67.73
14100 44.55000 65.78
14200 42.90000 63.79
14300 41.25000 61.77
14400 39.60000 59.72
14500 37.95000 57.62
14600 36.30000 55.5
14700 34.65000 53.34
14800 33.00000 51.15
14900 31.35000 48.92
15000 29.70000 46.65
15100 28.05000 44.35
15200 26.40000 42.02
15300 24.75000 39.65
15400 23.10000 37.25
15500 21.45000 34.82
15600 19.80000 32.35
15700 18.15000 29.84
15800 16.50000 27.3
15900 14.85000 24.73
16000 13.20000 22.12
16100 11.55000 19.47
16200 9.90000 16.79
16300 8.25000 14.08
16400 6.60000 11.33
16500 4.95000 8.55
16600 3.30000 5.74
16700 1.65000 2.89
16800 0.00000 0
Where did you get these numbers? You tested the motor?
No, they are a purely theoretical APPROXIMATION based on the Kt, Kv and stall current posted on the bane-bots website.
They are based on a model which works pretty well for DC motors in which torque is porportional to current and back emf is porportional to motor rpm. This model does not take into account inductive effects or internal bearing resistance of the motor.
Kt is a constant of porportionality relating motor output torque to electrical current input.
Kv is a constant which relates the rotational speed of the shaft to the voltage generated by the motor.
torque = I*Kt
Induced back emf(voltage created by the motor) = shaft speed * Kv
r= internal resistance of the motor = supply voltage/stall current.
combine these three and you get
torque = Kt*(Vin-Kv*rpm)/r
then for mechanical power in a rotating system we have
power = speed * torque
so
power = rpmKt(Vin-Kvrpm)/r
sorry ,that was a Terrible explanation, but its 3:29 am and i’m tired.
Does anyone know if there are any regulations against buying more (12:1) BaneBot CIM Gearboxes? Would it be FIRST Legal to have 4 BaneBot Gearboxes? I can’t find the rule to back this up.