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Thread: Brushed and Brushless on the same tranny

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Old 08-24-2011, 06:32 AM   #1
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Default Brushed and Brushless on the same tranny

I was thinkin' about mounting a brushed and a brushless motor to my ax-10 using one of those dual motor mounts.

The idea is to have a two speed truck. Use the brushed motor for crawlin and switch to brushless for speed.

Has this been done before?

Also, I'm not sure what the best way to switch power between the two motors would be. Any input would be appreciated.
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Old 08-24-2011, 07:08 AM   #2
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So many reasons why that is a bad idea, or at least one that isn't worth working out all of the issues.

It'd be simpler to use a 2 speed transmission, a good motor, and a 3 or 4s pack.
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Old 08-24-2011, 07:45 AM   #3
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Originally Posted by Duuuuuuuude View Post
So many reasons why that is a bad idea, or at least one that isn't worth working out all of the issues.

It'd be simpler to use a 2 speed transmission, a good motor, and a 3 or 4s pack.
Agreed, having a second motor (Brushed) at idle would create additional drag on the brushless motor. That is just one issue and my $0.02.
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Old 08-24-2011, 09:27 AM   #4
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Easiest way would be to have two speed controls..........use a futaba 4pk and set up a mix basically that turned off one.....

The big problem you are gonna have though, besides all the mounting issues is that whichever motor is not being used is going to end up acting as a generator.......that created power is gonna end up back in the ESC......not sure how all speedos would handle that.

I've thought of similar ideas, but just lots off issues to make it worth while.

Instead of a 2speed tranny, you could get a high end racing speed control, and program the timing boost to accomplish nearly the same thing. Before it was banned in spec class racing, guys were turning lap times in stock with 17.5t as quick as guys running mod.

Later EddieO
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Old 08-24-2011, 10:40 AM   #5
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RC4WD makes a two speed tranny you might want to take a look at.
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Old 08-24-2011, 12:02 PM   #6
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Thanks for the info everyone. It makes sense that if something hasn't been done before, there is probably a good reason why.
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Old 08-24-2011, 01:02 PM   #7
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That's it. i've decided to go 4 speed.

How you aski?

I'm gonna front mount a Summit 2 speed, and run a rc4wd 2 speed R2 as a "transfer case.

Dual hitec 7980's running off of 14V will ensure smooth shift engagement.

10,000KV on 6S should get it going.

It'll be top & nose heavy like a real truck, and have a transfer case for scale realism.
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Old 08-24-2011, 06:09 PM   #8
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Quote:
Originally Posted by EddieO View Post
The big problem you are gonna have though, besides all the mounting issues is that whichever motor is not being used is going to end up acting as a generator.......that created power is gonna end up back in the ESC......not sure how all speedos would handle that.
All esc's have to handle it at some time, whenever you let off the throttle and the rig is rolling, its doing as you said.

Wasn't it Novak that had regenerative braking in one of their esc's?
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Old 08-25-2011, 10:43 AM   #9
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Originally Posted by un4givn85 View Post
is this what people like to call "sarcasm"
i cant tell

yay for my first post
Congrats! And you better do a search!

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Originally Posted by Duuuuuuuude View Post
All esc's have to handle it at some time, whenever you let off the throttle and the rig is rolling, its doing as you said.

Wasn't it Novak that had regenerative braking in one of their esc's?
I thinkpst current esc's have regenerative braking now. Then again, with lipos being the norm, idk how it works. But, what Eddie O says is true. Take an moa rig using a punk dig. When yhe rig is off, and you turn one of the axles fast enough, it'll generate enough juice to spin the other axle. I.E. Spin the front fast and the rear will spin. NOT spin yhe left a d the right will spin (although it will, it doesn't prove the point.... Dicks)

Last edited by TSK; 08-25-2011 at 01:42 PM. Reason: Because Duuuuuude is a 3rd gen frog spiner =)
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Old 08-25-2011, 11:34 AM   #10
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Many speedos have regenerative braking, but yer talking a moderate amount of power being created during the braking action versus say a 17.5 brushless spinning at say full throttle making easily 125+ watts of power......not sure how any speedo would take that type of reverse input constantly.....

Later EddieO

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Originally Posted by Duuuuuuuude View Post
All esc's have to handle it at some time, whenever you let off the throttle and the rig is rolling, its doing as you said.

Wasn't it Novak that had regenerative braking in one of their esc's?
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Old 08-25-2011, 11:37 AM   #11
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Originally Posted by EddieO View Post
say a 17.5 brushless spinning at say full throttle making easily 125+ watts of power......not sure how any speedo would take that type of reverse input constantly.....

Later EddieO
Why don't you test that and get back to us with the results.
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Old 08-25-2011, 11:41 AM   #12
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Originally Posted by TheSCorpionKing View Post
Take an moa rig using a punk dig. When yhe rig is off, and you turn one of the axles fast enough, it'll generate enough juice to spin the other axle.
True, but the difference is that the moa has another motor to absorb the juice that the other one is creating.


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Spine the frog fast and the rear will spin.
I'm a third generation frog spiner and I can tell you I've never seen one spin its rear, no matter how fast you do it. I call bullocks on that one...
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Old 08-25-2011, 01:35 PM   #13
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Originally Posted by Duuuuuuuude View Post
I'm a third generation frog spiner and I can tell you I've never seen one spin its rear, no matter how fast you do it. I call bullocks on that one...
Cut me some slack. I was iPhone posting from my throne at 6 in the morning with my eyeballs squinting >_< and my brown eye squinting (_!_)

I know! Use a R2 dual dig trans as a transfer case to the actual trans. The motors will drive the front/rear output shaft, and the main input would be the outdrive to the secondary (main) transmission.

Then you us that to drive my 4 speed setup and voila, we have an 8 speed setup.

Last edited by TSK; 08-25-2011 at 01:46 PM.
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Old 07-26-2012, 01:42 AM   #14
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Default Re: Brushed and Brushless on the same tranny

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Originally Posted by Duuuuuuuude View Post
So many reasons why that is a bad idea, or at least one that isn't worth working out all of the issues.

It'd be simpler to use a 2 speed transmission, a good motor, and a 3 or 4s pack.

I do not post a lot. Duuuuuuuude you are right IT can be done but you will have more money doing it. Get a 2 speed transmission, a good motor, and a 3 or 4s pack. If you have your hart set on it pm me and i can help you set it up.
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