Dual Motors...and it WORKS!!!

[DANALLY]

I recently picked up a Jeep Hurricane that is being built on another thread. It got me thinking about running 2 motors. I have always been boggled that you can either have a rig that is slow and controlled or one that has great bump speed but not both. Big blocks are nice but aren't completely solving the problem. So here is my solution.

First off I made a mock up bracket out of carbon fiber. The actual one will be in aluminum.


As you can see the 2nd motor fits on top of the trany in an open area. No mods to the case at all.


I will be changing the Turbo motor pinion to a metal one soon. This was just for mock up.





So I had to make a way to control it. I am using a Mamba Micro ESC, a 3 channel TQ3 2.4ghz radio and receiver, and as you can see here a 3rd channel servo on a micro switch to send power to either the main motor or the turbo motor. I mounted the servo to the rear axle to gain space inside the rig for other electronics.

I had it all running but did not take video yet. I am still working out the chassis and body. The good news is that it WORKS!!! You can crawl slow and strong and at any moment (even at full throttle) hit the switch and the turbo motor kicks in instantly. The heat on the motors is a little more than normal but not bad at all. The extra drag of the second motor not under power is very minor. I ran a pack through it and found that I was very happy with the results.

This could also be two motors running at the same time but the battery would have to be huge. I tried that a long time ago on a dual trany/motor setup and it sucked down the 400mah battery in 5 minutes. This one ran for almost 15 minutes with constant switching to the turbo motor.

All I can say is that if you have the room for all the electronics this is a cool mod. I will post up a video soon.

 

[rik]

friggin sweet. cant wait to see the video!!!"thumbsup"

 

[EverettY]

Wow! You're stuff you do for the Micro's are amazing! Can't wait to see a vid of it Can you or are you going to compare the way it runs with one motor vs now with two motors?

 

[DANALLY]

friggin sweet. cant wait to see the video!!!"thumbsup"

Thanks man. I really think this could be alot of fun. I even had an easy idea for those who don't want to run a 3rd channel. Just put in a small toggle switch on the power wires to switch over manually from motor to motor. POOF!!! You have a crawler and a rock racer all in one!

Wow! You're stuff you do for the Micro's are amazing! Can't wait to see a vid of it Can you or are you going to compare the way it runs with one motor vs now with two motors?

Thanks.

I will do a comparison. Honestly the video will do it for me! It is a night and day between the 2 motors. When I had the crawler in the air it honestly sounds like nitrous was injected at full throttle. It's a load of fun.

Having the 3rd channel is really the way to do it and enjoy it. I just wish it was easier to fit all the darn electronics in a rig.

 

[EddieO]

Cool little project, remember though the motor not actually running is gonna act as a generator as it spins....that power has to go somewhere. Probably need to keep an eye on stuff so it doesn't fail...

Later EddieO

 

[DANALLY]

Cool little project, remember though the motor not actually running is gonna act as a generator as it spins....that power has to go somewhere. Probably need to keep an eye on stuff so it doesn't fail...

Later EddieO

I get you...but I don't. There is no power running thru it as the positive side of the dc voltage is broken. I could see the thought of possible interference but not a voltage danger. Plus the voltage doesn't have to "go" anywhere. It's like an outlet on your house...if nothing is plugged in completing the circuit, does that mean it needs a path to go otherwise? Not trying to be smart...just thinking it through. These motors aren't the same as a generator. They have a rotor and magnets but that's all. No stator to produce the electricity. They are a DC drive only. Please correct me if I'm wrong. I worked in power generation for a while and hope I remembered a few things;-)

 

[DANALLY]

Instead of editing my reply I will add a partial retract of the voltage creation. You are correct, a d/c motor can create a small amount of electricity in one direction. I am still not sure about it having to go somewhere. I remember now in school doing the experiment spinning a dc motor by hand hooked to a flashlight bulb. It took a good size dc motor to generate much of anything.

I also wonder if all the capacitors on the motor might negate that effect? And would you even be able to see power from such a small dc motor? All questions I want to find answers too.

In this case the motor leads are disconnected by the switch thus the power goes no-where. I suppose the caution would be letting something touch the lead on the motor while spinning as it could be a source of power depending on the rotation and could damage something coming into contact?

Golly. You are making me think. Thats not always a good thing. :shock:

 

[rapttor]

Is there any benefit of running 2 motors that are the same.Like lets say 2 100 turn's working in the same time ?How will this react to battery life/speed/torque/temp/.... ?

 

[Hittman]

Wow, this is interesting. I would like to see how this turns out"thumbsup"

 

[DANALLY]

Is there any benefit of running 2 motors that are the same.Like lets say 2 100 turn's working in the same time ?How will this react to battery life/speed/torque/temp/.... ?

Two motors of the same turn and gearing is powerful. I kinda did it once before just with 2 trannys. The big deal is that it really does suck the battery down...FAST! To be honest a big block is better.

Wow, this is interesting. I would like to see how this turns out"thumbsup"

I tell you it's fun to drive. Like having 2 rigs in one. The motor heat is a worry on the 40t motor. It get's hot with prolonged use. The truth is that you only need to use it for short bursts or even for 20 seconds max. The 100t motor seems to be about the same in heat as a normal rig. Although it does get time to cool off while using the other motor and visa-versa. It's a interesting marriage of speed and torque. It's just so fun having that little button that acts like a turbo or nitrous. :ror:

 

[Hittman]

I tell you it's fun to drive. Like having 2 rigs in one. The motor heat is a worry on the 40t motor. It get's hot with prolonged use. The truth is that you only need to use it for short bursts or even for 20 seconds max. The 100t motor seems to be about the same in heat as a normal rig. Although it does get time to cool off while using the other motor and visa-versa. It's a interesting marriage of speed and torque. It's just so fun having that little button that acts like a turbo or nitrous. :ror:

This sounds awsome!!! "thumbsup"

 

[BerticusPryme]

There is no sounds awesome to this this is awesome. I am happy he figured this out but at the same time I want to throw rocks at him for doing this as now I have some twisted ideas in my head.

 

[EddieO]

I get you...but I don't. There is no power running thru it as the positive side of the dc voltage is broken. I could see the thought of possible interference but not a voltage danger. Plus the voltage doesn't have to "go" anywhere. It's like an outlet on your house...if nothing is plugged in completing the circuit, does that mean it needs a path to go otherwise? Not trying to be smart...just thinking it through. These motors aren't the same as a generator. They have a rotor and magnets but that's all. No stator to produce the electricity. They are a DC drive only. Please correct me if I'm wrong. I worked in power generation for a while and hope I remembered a few things;-)

Any brushed motor spun by other means will act as a generator, that's just how it works. The standard for testing KV is to spin a motor at a known RPM and measure the voltage its produces. Size does determine how much they output, as does wind count among other factors. An outlet at your house is a bit different......

Instead of editing my reply I will add a partial retract of the voltage creation. You are correct, a d/c motor can create a small amount of electricity in one direction. I am still not sure about it having to go somewhere. I remember now in school doing the experiment spinning a dc motor by hand hooked to a flashlight bulb. It took a good size dc motor to generate much of anything.

I also wonder if all the capacitors on the motor might negate that effect? And would you even be able to see power from such a small dc motor? All questions I want to find answers too.

In this case the motor leads are disconnected by the switch thus the power goes no-where. I suppose the caution would be letting something touch the lead on the motor while spinning as it could be a source of power depending on the rotation and could damage something coming into contact?

Golly. You are making me think. Thats not always a good thing. :shock:

The capacitors will little effect, they are there to cancel out electrical noise, not to swallow voltage. The fact the leads disconnect from the ESC is good, as that means the power is not flowing back into it. An ESC is designed for some feedback, but not a ton. At this point the power is basically staying in the motor, so increased comm wear and such.

Later EddieO

 

[DANALLY]

Any brushed motor spun by other means will act as a generator, that's just how it works. The standard for testing KV is to spin a motor at a known RPM and measure the voltage its produces. Size does determine how much they output, as does wind count among other factors. An outlet at your house is a bit different......



The capacitors will little effect, they are there to cancel out electrical noise, not to swallow voltage. The fact the leads disconnect from the ESC is good, as that means the power is not flowing back into it. An ESC is designed for some feedback, but not a ton. At this point the power is basically staying in the motor, so increased comm wear and such.

Later EddieO

Thanks for the clarification. I never knew that about the Kv on the motors for how they tested them. Cool info.

I will keep an eye on the motors and how they perform. I am using 2 new motors so the input will be good.

Thanks again!

 

[ittybitty]

An easy way to illustrate that this happens is to take an MOA rig (powered off) that's running a single ESC and a punk dig and spin the wheels on one axle by hand and watch the front tires rotate :shock:

 

[Elastokinematic]

LOL!! leave it to you to come up with a solution.

just a thought... How about a way to run 2 batteries. Switch from 1s to 2s. Seems like that would be possible with some relays and such..

 

[DANALLY]

An easy way to illustrate that this happens is to take an MOA rig (powered off) that's running a single ESC and a punk dig and spin the wheels on one axle by hand and watch the front tires rotate :shock:

I forgot about that! I used to have a Berg. Thanks for the visual help!

LOL!! leave it to you to come up with a solution.

just a thought... How about a way to run 2 batteries. Switch from 1s to 2s. Seems like that would be possible with some relays and such..

It could be done but I don't like 1 cell batteries very much as the steering is so weak. I also didn't like the idea of having the batteries discharging at different rates. It could be a problem if you don't catch when one is getting too low. I'm sure it could work tho.

Just wait till u see the motors run. I think it's gunna surprise everyone on how well it works. "thumbsup"

 

[rik]

Video Dan ! Wheres the video?! Lmao sorry , other than you re-releasing the predator motors, I haven't been this excited about parts/mods for the micro in a long time. This definitely has possibilties..

 

[DANALLY]

Video Dan ! Wheres the video?! Lmao sorry , other than you re-releasing the predator motors, I haven't been this excited about parts/mods for the micro in a long time. This definitely has possibilties..

TRUST ME I WANNA DO IT!

It was 114 degrees here today and I worked outside...I'm drained. And to top it off my garage is 120 degrees. I have a workshop in there with an a/c unit. It's been running for 1/2 hour and the room is slightly cooler and the garage is up to 130 degrees. I need a swamp cooler in there that doesn't put out the heat as a side effect. I open the garage door a bit and run fans to take the heat out and it still gets hotter :twisted:

I will have a video in the next few days...even if it's just a quick one holding it in the air to show the two speeds.

I PROMISE :shock: :shock: :shock:

 

[chevy55]

Get in the house & hold it in your hand, I just want a vid :ror: