torque - brushed vs brushless

[studysession]

Hi -
I have a bit of an issue. I love brushless motors. The power and torque is amazing.

I have a Micro RS4 that has a 540 19t double brushed motor in it. Loads of power and torque. I am running a 30t pinion and it is amazing.

Because the car was never designed for a big motor like this I am limited on the size of pinions I can use. If I put a 540 brushless motor (Lehner 5300 basic or Hacker C40) - It cogs and does not go anywhere when it is sitting on the ground.

I really want to run a brushless motor and can not put anything physically bigger than the standard 540 short can in it. Need to run with the 30t pinion and that is fine for ANY brushed motor I put into this little 1/18 scale car. But not for a brushless motor.

Any recommendations???? THANKS!@

[ygguB naM]

Why don't u just get a super hi rpm brushless motor so u don't have use such big pinion.

[TimisTim]

Modify your motor plate and run a lehner. They are pretty short motors and a little smaller than a standard 540 like a feigao. A higher rpm motor would just make the cogging even worse. Low rpm and higher voltage would be much better.

[chilledoutuk]

you dont mention what controller you are using and thats the main cause of most cogging issues a pants controller

[studysession]

Thanks for the replies -

ygguB_naM - Because of how small the car is. I cannot use a small pinion because I cannot put a bigger spur on there. Wish I could.

TimisTim - I can fit my Lehner 5300 Basic and my Hacker C40 motors just fine. Also my Chili Pepper motors. Just no matter which I use - It is over geared and won't move on the ground but the wheels spin in the air.

chilledoutuk - I do not have it anymore - I but I did try a Schulze. Fried it in another car project though. I have also tried it with my MTroniks controller. The BK-Warrior is physically to big to fit.


As I said - using almost any 540 brushed motor it works fine. Pushes the car without a problem. I am using a MTroniks Cyrus Pro forward only ESC for my brushed motors.

I really want to use my 540 brushless motors in this car. But not sure how to over come this issue.

Thanks

[kufman]

What kind of batteries are you using? They may not be able to supply the load.

[TimisTim]

I was saying to modify the motor plate to allow the use of other smaller pinions. Just lengthen the mounting holes so the motor can be adjusted more.

[Neon_Dave]

TimisTim, It's not that simple. You already have to sand the axle housing down to the bearings to fit a standard 540, just to be able to use a 27T pinion. Changing the spur is definitely not an option, either.

Studysession, there's not really much you can do, as far as gearing and motor placement.

A micro RS4, with a 540 and mods will be roughly half the weight of a 1/10th electric tourer. Theoretically, you should be able to gear it twice as high. With BL motors, that may not be the case. They may not have the initial torque required to move the car with that gearing.

What I would like to know is what kind of batteries you're using, as that's the most likely problem. My suggestion: Sub-C's. They will provide much longer run times and also more than sufficient power to just about any motor that you can manage to fit into the MRS4. If you're using the smaller 2/3 cells, they may just not be able to supply the motor with the amps it needs to get going, especially with that much wieght.

I personally use a 17X2 motor and a 31T pinion, and sub-C's (of 1500 mah capacity, 5 of them) in my Micro. No problems whatsoever regarding the motor not being able to push it. It can burnout for about 3 seconds too ;)

Hope this helps...
Dave :)

[studysession]

I was saying to modify the motor plate to allow the use of other smaller pinions. Just lengthen the mounting holes so the motor can be adjusted more.


I modified as much as I could. Can't do anymore to it without ruining something. Thanks


As for the batteries - I forgot the exact ones I was using before which had more punch. I wrapped the cell's so can't pull the info off anymore. When placing cells directly on carbon-fiber I prefer wrapping them in tape or something because CF can be a conductor if you are not careful. But I can use the same cells with proper gearing in a 1/10 scale car and they work great. I think it is just geared to high for what they can hanlde - Was hoping for other ideas that I have not thought of yet.

I did sand the axle down and will be TRYING and I stress TRYING the 27t pinion. Just picked up the pinion today.

With a 19t brushed motor and 30t pinion. I can radar the car at 47 - 48 MPh and not even full throttle. I would LOVE to get the brushless motor working properly and see how fast it can go if that is from a 19t brushed motor.