Timeline for Effective ways to drive a single shaft with multiple motors?
Current License: CC BY-SA 3.0
7 events
| when toggle format | what | by | license | comment | |
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| Jul 16, 2020 at 20:10 | comment | added | Anthony | @OlinLathrop What happens in the closed loop system with the same setup? How does that work or is it not possible? | |
| May 11, 2015 at 22:28 | comment | added | trycatch | "I don't see how gear teeth have anything to do with this as you'd be using shaft couplers." Oh. OH. I didn't even think about having them both DIRECTLY DRIVING THE SAME SHAFT. In my mind I was going: Motor A gear driving -> gear on shaft <- Motor B gear driving And I saw a potential for one gear to slip and get out of sync with the gear on the shaft and cause grinding / catching. | |
| May 11, 2015 at 22:17 | comment | added | Level River St | You can avoid this problem by instead selecting two nominal 6V motors and connecting them in series, so they are sure to have the same current through each (and hence virtually identical torque). Though in both cases you should think about what the effect the failure of one motor will have on the other. | |
| May 11, 2015 at 22:05 | comment | added | Level River St | If the motors are permanent magnet DC type and have the same nameplate but different characteristics (due to manufacturing inconsistencies) it's better to connect in series than parallel. This is because motors act as dynamos, producing a back voltage that must be overcome by the applied voltage. Example: 2 motors, one with back voltage 10V at some speed, the other with back voltage 11V. Both have resistance 1 ohm. Connect them to a 12V supply, motor A draws (12-10)/1=2 amps, motor B draws (12-11)/1=1 amp. Torque is proportional to current, so there's different current/torque in each motor. | |
| May 11, 2015 at 19:59 | comment | added | Olin Lathrop | @tryc: With both motors connected to the same shaft, both will always run at the same speed. I don't see how gear teeth have anything to do with this as you'd be using shaft couplers. There is no need for any gears between the two motors. At a given speed the only question is how much torque (positive or negative) the motor is putting onto the shaft. With the same model motors connected electrically, the torque at the same voltage and speed is going to be pretty close. Even if one is, say, 80% of the other, no real harm will be done other than less than optimum use of the motors. | |
| May 11, 2015 at 19:53 | comment | added | trycatch | Hm, really? Somehow I imagined the worst case would be something like one motor running at X rpm and the other either running at some non power of two fraction, causing the teeth to occasionally meet or something. But I suppose the higher powered motor will keep pushing things along? | |
| May 11, 2015 at 18:56 | history | answered | Olin Lathrop | CC BY-SA 3.0 |