Brushless Emaxx set up

hi all,

I have my e-maxx running on the Novak HV set up for a while and would like to go one step further...

I currently have a BK 9918 Bruhsless ESC, and a BK 20S (16XX RPM/V) motor in my hand, i used to run 2 pack of 7.2V NiMh in parallel.....since i also play boats, so i have a few packs of 9.6V NiMH. I planned to hook up the system with 2 pack of 9.6V in parallel (= 19.6V).....

Just wondering what kinda gear ratio should i be running for a more efficient setup (normal run time, acceptable top speed)
What size of pinon & Spur gear should i go for to obtain that?


Thank you in advance for your suggestion.

BR
Tom

Anyone here can give me some advise?

Thank you~~~:036:

[jhautz]

jp, welcome to the forum.:018:

Your original post is slightly confusing. :confused: I think this is why you didn't get a response.

I'm not quite sure what motor it is you are talking about here. (BK 20S?) I am guessing you mean a BK Wanderer motor. It sounds like its a S (short) can motor with a reletivly high turn. Maybee a 19turn or so. If I am guessing right you will need a bigger motor for a sucessfull setup in an emaxx. at least an L size motor, but preferably an XL size motor.

The 9918 ESC should work fine.

I also think that you mean you have 2 7.2Volt battery packs and 2 9.6Volt packs. You want to use these in series, not in parallel. In parallel you will double the capacity of the packs not the voltage. Hooking 2 9.6v packs in series will achieve a 19.2volt setup.

A good motor choice for 16 cell (19.2v) setup would be BK Wanderer 9XL or the Feigao 540C 9XL motor. In an emaxx this would give you some very nice power and speed and still acieve pretty nice run times.

If you can let us know better what motor it is that you have we might be able to help you better. Can you be more specific as to which motor you are refering to?

Hi Jhautz,

Thanks for the information,

Well yes, i was suppose to say connect the batteries in series (sorry~~)

i will try to take a few pictures of the motor tonite.......so can you please let me know what sort of Pinon gear will suit the motor you have mentioned above? And how many KV is that Feigao 540C-XL motor? And any idea about the Spur gear size? I have pretty much everything in stock form from the original E-maxx..which already did a pretty good job on the HV maxx setup....but i only fear the original setup willl be destroyed if the new system is too powerful.....

Thanks again for the info~~~

BR
Tom

I have just checked my motor,

Its indeed the BK Wandarer series 20S with 20 Turn, the output is about 1598rpm/V........is that too small of a motor for E-maxx?

Umm..Thank you for all of your advice~

BR
Tom

[jhautz]

Sorry, I wasnt intending to nit pick on that last post. :032:

Yes. That motor will be to small. The motor will be overheating in no time in a vehicle the size and weight of an E-maxx. Look into getting yourself an XL size motor. shoot for a total motor rpm of around 35K rpm when selecting your new motor. That should give you a nice balance of speed and runtime. If you want longer run time choose a motor that will run at a lower rpm.

What I mean choose the battery voltage you will be running, then choose a motor that based on that voltage will result in a max rpm of around 35,000. If you want more speed, choose a wind that will get closer to 40K rpm and for more run time choose a wind that will go closer to 30K rpm.

This is just a rule of thumb to get you in the ballpark. The weight and tire size you are running can effect this, but it a good place to start.

Originally Posted by jhautz

Sorry, I wasnt intending to nit pick on that last post. :032:

Yes. That motor will be to small. The motor will be overheating in no time in a vehicle the size and weight of an E-maxx. Look into getting yourself an XL size motor. shoot for a total motor rpm of around 35K rpm when selecting your new motor. That should give you a nice balance of speed and runtime. If you want longer run time choose a motor that will run at a lower rpm.

What I mean choose the battery voltage you will be running, then choose a motor that based on that voltage will result in a max rpm of around 35,000. If you want more speed, choose a wind that will get closer to 40K rpm and for more run time choose a wind that will go closer to 30K rpm.

This is just a rule of thumb to get you in the ballpark. The weight and tire size you are running can effect this, but it a good place to start.

Thank you so much~~........Now i know where to begin with....

Lets say if i am going for the Feigao 540C XL motor.....with my standard E-maxx Spur gear, what size of Pinon should i go for? Or do i jsut leave it as stock?

I just fear the gear ratio will over heat the motor in no time as well....so better ask in advance. :027:

By the way, here are some pics of my E-maxx~~~









BR
Tom

[jhautz]

Nice looking ride. :027:

It'll depend on which motor you go with, but assuming the 9xl on 16 cells I recomended below, I would say 18/66 or 20/66 would be a decent place to start considering you are running those oversize tires. With a 9xl on 5s Lipo I was running 22/66 w/ no heat issues. But I wasnt running tires that big either.

What tires and rims are those?

Originally Posted by jhautz

Nice looking ride. :027:

It'll depend on which motor you go with, but assuming the 9xl on 16 cells I recomended below, I would say 18/66 or 20/66 would be a decent place to start considering you are running those oversize tires. With a 9xl on 5s Lipo I was running 22/66 w/ no heat issues. But I wasnt running tires that big either.

What tires and rims are those?

Okie, i will give that a try.

The tire and wheel that is now on the car is from Gmade (used to be for crawling)...but i think it looks better putting it on the E-maxx....i also have the REVO tire and rims to play with if this does no good to the car...hehe