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Slash 4x4 MT Conversion

Slash 4x4 MT Conversion

Old 12-20-2011, 12:46 AM
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Okay, i've upgraded basically everything on my Slash 4x4 PE for a MT Conversion. My question is with gearing. I'm using 2.8" wheels with Pro-Line Badlands on them. Running stock VXL Brushless system.

With the larger diameter wheels/tires, where should I go with my gearing?? I've used the stock 13/54 gearing with a 2-cell SMC LiPo, but after an 8000 mah battery, the motor is screaming hot and ESC is cold. I tried the 18/54 gearing and got the ESC a little warmer than room temp, but motor still super hot. Tried 20/54, and the ESC thermalled after about 4 minutes, with motor still superhot.

I read somewhere that if the motor is hot and ESC is cold, that I am undergeared, so that's why I started going up. Should I go the other way? Haven't tried anything lower than 13/54.
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Old 12-20-2011, 01:17 AM
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Originally Posted by sdtech58 View Post
Okay, i've upgraded basically everything on my Slash 4x4 PE for a MT Conversion. My question is with gearing. I'm using 2.8" wheels with Pro-Line Badlands on them. Running stock VXL Brushless system.

With the larger diameter wheels/tires, where should I go with my gearing?? I've used the stock 13/54 gearing with a 2-cell SMC LiPo, but after an 8000 mah battery, the motor is screaming hot and ESC is cold. I tried the 18/54 gearing and got the ESC a little warmer than room temp, but motor still super hot. Tried 20/54, and the ESC thermalled after about 4 minutes, with motor still superhot.

I read somewhere that if the motor is hot and ESC is cold, that I am undergeared, so that's why I started going up. Should I go the other way? Haven't tried anything lower than 13/54.
Yeah, you are for sure going the wrong way. I would try 11/54 and check temps on the motor. The VXL motor likes to run hot and it is working harder now to spin heavier/taller wheels and tires.
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Old 12-20-2011, 03:43 AM
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I run 31/76 on my Rustler and get no issues with heat on either the motor or the esc.

You may want to go that direction and see if it helps.
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Old 12-20-2011, 08:01 PM
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okay. I'll have to go to the hobby store to get an 11T to try the 11/54. Thanks.
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Old 12-21-2011, 10:41 AM
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Come time for motor upgrade I would try a castle 1410 3800kv. You should be able to run your stock gearing with that motor with no heat issues and have a lot more torque over the 2 pole vxl.
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Old 12-26-2011, 03:09 PM
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Thanks for the help n2trouble. Ended up getting an 11t and 10t while at the hobby shop. Put the 11t on, but I'm pretty sure I fried my motor messing around with the super high gear ratios prior to that. It was stuttering really bad, superhot after about 30 seconds and eventually didn't want to run at all.

Ended up getting a new VXL motor and throwing that on last night with the stock 13/54 setup. Ran about 5 minutes (it was midnight and I was pissing off my neighbors dogs...LOL...) and I could hold my finger on the motor as long as I wanted to when I was done. Ran the rest of the pack and it was getting a little bit hotter than after 5 minutes, but I could still hold my finger on the motor for an extended period of time. ESC with cooling fan was still at ambient temperature (40 degrees).

Running Robinson Gen3 slipper with it cranked all the way down, then backed off 1/4 turn. I know the X-Duty CVD's and that steel spur added quite a bit of weight to the drivetrain. Larger wheels and tires, etc... Set gear mesh using the 2 sheets of paper between gears method, and it doesn't seem as though there is any binding anywhere. For bashing only, so there is alot of start/stop driving.

Is there any truth to what I read about bumping up my ratio, maybe like 14/54, to get some heat into the ESC? Will this lower my motor temps? What is the safe temp range to run these brushless motors at? Don't really want to burn up another motor.

I've been a nitro guy for years, but this is my first crack at electrics. Hope all this gear ratio stuff isn't too elementary...Might try different motor if I burn up another one.

Thanks
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Old 01-05-2012, 12:43 AM
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If your still running the stock motor and esc I would run 12t for the pinion if your running larger tires for your mt conversion
You should be looking into a better esc/motor as I see you are already having problems with the vxl setup
I would look into the 3800kv or 2400kv castle motor or something similar and a good esc

And about the temps you never want to go above 180 degrees on either the esc or motor and make sure your mesh is perfect, just a tiny bit of play between the spur gear and pinion
A tight mesh will definitely heat things up

Last edited by Ramos617; 01-05-2012 at 12:46 AM. Reason: added info
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Old 01-05-2012, 06:28 AM
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so is it done ? and how does it handle/ perform ?
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Old 01-05-2012, 03:13 PM
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I run 11/52 on my sons VXL slash 4x4 on 3s lipo with pede tires no heat issues. Run 10/54 on my bros on truggy tires on 3s. He's running the castle sc system.

If your going to run lipo/brushless....Buy a temp gun,,,
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Old 01-06-2012, 01:31 PM
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Originally Posted by timritchieblue View Post
I run 11/52 on my sons VXL slash 4x4 on 3s lipo with pede tires no heat issues. Run 10/54 on my bros on truggy tires on 3s. He's running the castle sc system.

If your going to run lipo/brushless....Buy a temp gun,,,
What body is that?

Sweet truck. mine is very similar with the proline baja bug body and the wheels rub bad. looking for alternatives.

BTW running a 9t pinion on 3s can't remember the spur, seem to remember fitting such a big spur in there was difficult. temps are perfect but the stock motor screams. I think i'm gonna go 2s with a higher c just so the motor bearings can last.
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Old 01-06-2012, 02:24 PM
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Originally Posted by DG40 View Post
What body is that?

Sweet truck. mine is very similar with the proline baja bug body and the wheels rub bad. looking for alternatives.

BTW running a 9t pinion on 3s can't remember the spur, seem to remember fitting such a big spur in there was difficult. temps are perfect but the stock motor screams. I think i'm gonna go 2s with a higher c just so the motor bearings can last.
Its a ford svt raptor, you got to get the 2wd, or it will be a s.c. body. Got a baja bug body too. Baja body was super tough, but it finaily ripped the rear off.
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