Dual Motor ESC

[ursanix]

Would a dual motor ESC keep both motors running the same speed regardless of traction?

I am running dual N20 reduction motors on a HobbyWing 1625 on my CR18 with a DumboRC 6ch receiver and controller The torque is great but occasionally when climbing steep hills the rear tires will stall while the fronts continue to move. A little more throttle will get the rear going, but I'd prefer it didn't happen. Wondering if an ESC meant for dual motors (maybe like a micro tank ESC?) would be able to always keep both motors spinning at a near-identical RPM regardless of traction.

I've searched these forums and while it seems there is information about dual motor ESCs none of them seem to answer my question about keeping the of both motors the same RPM regardless of resistance.

I've tried using the 100t Atlas motor on a 9t pinion but it's still too jumpy for my preference.

[Zenith the Zero]

Dual motor ESC’s, with appropriate radio gear, allow you to change the power to each motor(axle) to compensate for the difference in load the motors are seeing. That difference in load is why the rear axle stalls as it starts climbing. The more vertical the angle, the more the weight is transferred from front to rear, the higher the load.

[vinceherman]

The ESC does not know what speed the brushed motor is going. It can only manipulate the average voltage that it sends to the motor.

[Shape_Shifter]

I have twin motors on a couple of my micro trucks. For both trucks I use a Tekin B1R ESC but it doesn't really matter. These little motors require very little current and most small ESCs can handle two N20s.


On this model, each motor drives a separate axle like yours, and yes, even with a B1R ESC, in certain conditions the rear axle is a little slower but not a problem IMO. This also happens with models like a Tamiya Clod Buster with separate MOA (motor on axle) but single ESC. As Zenith mentions, dual ESCs and radio programming can help prevent that and is something competition MOA crawlers use.





With this dual motor setup, there is no difference in load and both motors run at the same RPM (and double the low voltage torque for low speed crawling).

[ursanix]

Originally Posted by Shape_Shifter

I have twin motors on a couple of my micro trucks. For both trucks I use a Tekin B1R ESC but it doesn't really matter. These little motors require very little current and most small ESCs can handle two N20s.


On this model, each motor drives a separate axle like yours, and yes, even with a B1R ESC, in certain conditions the rear axle is a little slower but not a problem IMO. This also happens with models like a Tamiya Clod Buster with separate MOA (motor on axle) but single ESC. As Zenith mentions, dual ESCs and radio programming can help prevent that and is something competition MOA crawlers use.





With this dual motor setup, there is no difference in load and both motors run at the same RPM (and double the low voltage torque for low speed crawling).

That gearbox is incredible, and would solve all my problems. I was just looking for something like that today. I wonder if I could make it work for CR18. What's the reduction on it? Or is it 1:1 with a dual output and you get all the reduction from the N20s? I also wonder if you can put any of the other motors like the stock 050 into the reduction gears for some different ideas?

I would love to know where you got that gearbox...

[Shape_Shifter]

Originally Posted by ursanix

That gearbox is incredible, and would solve all my problems. I was just looking for something like that today. I wonder if I could make it work for CR18. What's the reduction on it? Or is it 1:1 with a dual output and you get all the reduction from the N20s? I also wonder if you can put any of the other motors like the stock 050 into the reduction gears for some different ideas?

I would love to know where you got that gearbox...

Are you talking about this one?

https://www.ebay.com/itm/Dual-Twin-M...8AAOSwvP9aojwr

[ursanix]

Originally Posted by Shape_Shifter

Are you talking about this one?

https://www.ebay.com/itm/Dual-Twin-M...8AAOSwvP9aojwr

No, I already have that one, it's currently installed on my CR18 with 2x 100RPM N20 motors.

The other one with both N20s on the one big spur gear... this one:

Originally Posted by Shape_Shifter

With this dual motor setup, there is no difference in load and both motors run at the same RPM (and double the low voltage torque for low speed crawling).

[Shape_Shifter]

Originally Posted by ursanix

No, I already have that one, it's currently installed on my CR18 with 2x 100RPM N20 motors.

The other one with both N20s on the one big spur gear... this one:

That was from an RCCrawler user named Fungi. He also made the Scorpion frame that Yoda is driving. Most of his stuff was made for the Losi Micro Crawler but could easily be adapted to any 1/24 micro truck. The gearbox that the dual motor plate is on is a stock Losi micro crawler. You can still get those spur gears on ebay.


Yeah, the box you have will vary the speed of either motor depending on load, but I have gotten used to it.

If you are looking for low-speed torque with stock electronics, try the divorced transfer case from a RTG Adventure V2 in your CR-18 like I did in my Atlas.

[ursanix]

Originally Posted by Shape_Shifter

That was from an RCCrawler user named Fungi. He also made the Scorpion frame that Yoda is driving. Most of his stuff was made for the Losi Micro Crawler but could easily be adapted to any 1/24 micro truck. The gearbox that the dual motor plate is on is a stock Losi micro crawler. You can still get those spur gears on ebay.


Yeah, the box you have will vary the speed of either motor depending on load, but I have gotten used to it.

If you are looking for low-speed torque with stock electronics, try the divorced transfer case from a RTG Adventure V2 in your CR-18 like I did in my Atlas.

Oh wow, that's an awesome build. I'll check it out. I actually have two of the 100t 050 motors from the Atlas sitting around, but even with the 100t and a 9t pinion on the stock CR18 transmission I didn't feel like there was enough low-end torque.

[Shape_Shifter]

Originally Posted by ursanix

Oh wow, that's an awesome build. I'll check it out. I actually have two of the 100t 050 motors from the Atlas sitting around, but even with the 100t and a 9t pinion on the stock CR18 transmission I didn't feel like there was enough low-end torque.

This is the problem with virtually all micro "crawlers". Ive done all kinds of crazy transmission mods to fix that. Including a couple of micro chain drives.

[Unclelee]

Originally Posted by Shape_Shifter

This is the problem with virtually all micro "crawlers". Ive done all kinds of crazy transmission mods to fix that. Including a couple of micro chain drives.

Link to chain drive parts?

Sent from my SM-G970U using Tapatalk

[Shape_Shifter]

Originally Posted by Unclelee

Link to chain drive parts?

Sent from my SM-G970U using Tapatalk

https://sdp-si.com/