TinkerMania
1 µW
Is there any reason to or not to use 2 different hub motors, one with lower voltage? Just wondering about increasing power on the low end and speed once cruising down the road. Working on a four wheel cargo transporter.
Dual hub motors with different voltages?
- Thread starter TinkerMania
- Start date
j bjork
1 MW
It should be possible to run 2 voltages, but I cant see any reasonable reason why.
Which two wheels will be powered in your design?
TinkerMania
1 µW
It would be the two rear wheels and it was just a thought laying in bed. Did not know if the different windings if the all axle grin motor would give benefit of better torque down low and greater speed at the higher end. Understand I hadn't had any coffee yet.
If the two systems are completely independent, including battery, motor, controller, etc., there's no reason it won't operate.
How much each system will contribute to the system operation under various conditions you can test using the 2WD option in the ebikes.ca simulator; it can show you simultaneous graphs for each this way, for the same riding conditions.
If the difference in system voltage, motor winding, etc., between the two systems is great enough, you could have drag on the low-speed system while at the highest range of the high speed system, with two DD hubmotors, because the lower speed motor will be acting as a generator once it's above the voltage the battery could supply to it.
While the SB Cruiser (and Crazybike2 before it) uses a common battery, it has always had dissimilar motors and controllers on each of the powered wheels (usually the two rear). So it takes some learning to control with the different traction and braking torque curves on each side, since it will pull to one side or the other differently under various conditions, speeds, and control inputs. The present setup with a Phaserunner v1 on the left side and v6 on the right, running two similar but not identical ex-A2B Ultramotors, is the most similar response that I've had out of all the various systems I've used over the years.
How much each system will contribute to the system operation under various conditions you can test using the 2WD option in the ebikes.ca simulator; it can show you simultaneous graphs for each this way, for the same riding conditions.
If the difference in system voltage, motor winding, etc., between the two systems is great enough, you could have drag on the low-speed system while at the highest range of the high speed system, with two DD hubmotors, because the lower speed motor will be acting as a generator once it's above the voltage the battery could supply to it.
While the SB Cruiser (and Crazybike2 before it) uses a common battery, it has always had dissimilar motors and controllers on each of the powered wheels (usually the two rear). So it takes some learning to control with the different traction and braking torque curves on each side, since it will pull to one side or the other differently under various conditions, speeds, and control inputs. The present setup with a Phaserunner v1 on the left side and v6 on the right, running two similar but not identical ex-A2B Ultramotors, is the most similar response that I've had out of all the various systems I've used over the years.
Last edited:
Chalo
100 TW
Hub motors don't have voltages. They have a fixed RPM per volt, but up to some impractically high input voltage, they don't care what voltage they run on.
One good reason not to use motors with very different RPM per volt (drawing from the same battery) is that once the top speed of the slower one is reached or exceeded, it becomes dead weight (at best) or a source of drag the other motor must work against.
A good reason not to use two different motors running at different voltages is then you have to keep, maintain, and charge two batteries.
One motor with twice the power will almost always give you better power, speed, and efficiency than two motors trying to do different things. Likewise, two motors with the same top speed will usually be faster and more efficient than two working together at different speeds.
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