gearing for 8xl in maxx ?

[speedy]

Hi !

Coud i use a smaller piniongear if i put a feigao 8xl motor in my 3905 emaxx ?
The stock gearing is 19/68 ? i'l run it on 4s lipo !

[neweuser]

ARe you running stock diffs? I assume this is 32p gears, if so, you may want a smaller pinion. But i have not ran 32p for sometime. so someone else may want to chime in here.

[A RC Dude]

i was just about to ask that question. my maxx is being converted to BL. it's still stock now but soon i'll be running a 8XL motor, 12 cells, and i'll get 3.3 diffs and all installed! but i have no clue how to gear it.

[Arct1k]

Use Brians's Speed calculator but you have to change the e-maxx gear ratio as it is different on the new EMAXX...

http://scriptasylum.com/rc_speed/

I believe:

Differential Ratio: 3.307
Transmission Ratio: 1.16

[suicideneil]

The new tranny ratio is 1.83:1 (stock single speed). The diff ratio is the same as the stock revo or emaxx 3906.

[speedy]

Hi !

Are the neu 1521 size motors to big for a 3905 e-maxx ?

I'd like to have the most effichent bl system possible for max 6s lipos and topspeeds of 40mph ! and bed able to bash hard for 30-40min without overheating the system

[BL-Power]

A Neu 1521 will kill your complete drivetrain when you on the throttle the first time. I you like much power, then take a Neu 1515 and if you want a good controllable setup, take a Neu 1512.

[Patrick]

1515 1.5y (1500kv) on 6s geared for 40mph should give fairly low amp draw and cool temps.

[speedy]

Are the neu 1512 motors stronger and more effichent than a feigao 8xl ?

[BL-Power]

The Neu Motors are more efficient than the Feigaos.

[jnev]

They are much more powerful and way more efficient than the 8xl motor.

[suicideneil]

Neus produce roughly twice the torque of the feigaos (4pole vs 2pole), so you could use a smaller motor like the 1512 and get the same results as using the larger feigao XL motor. Only snagg is price difference, but since you are interested in Neus, I guess you knew that already.

[speedy]

ok

So if put a neu 1515xxx motor in my e-maxx and run it on the same nuber of lipocells and gearing it will pull alot less amps and manage to get more rpm's to the wheels because of the tq of the neu ? how big difference in ampdraw will it be if i gear a neu with the same kv the same way as my feigao 8xl ? 20% ? less or more ?

By the way is there a better motor alternative than neu's ?

[suicideneil]

Originally Posted by speedy

ok

So if put a neu 1515xxx motor in my e-maxx and run it on the same nuber of lipocells and gearing it will pull alot less amps and manage to get more rpm's to the wheels because of the tq of the neu ?how big difference in ampdraw will it be if i gear a neu with the same kv the same way as my feigao 8xl ? 20% ? less or more ?

It will draw slightly fewer amps in theory, but its more about efficiency. The feigaos are cheaply made motors, and waste alot of energy as heat, where-as the Neus are very well made and turn more of that energy into phyiscal power, in terms of wattage (both motors will draw the same current, but the neu will use it more efficiently). As a result you can gear the Neus a fair bit higher, and they will still run fairly cool compared to a feigao treated the same way. RPMs is simply relative to voltage and which motor KV you choose.

1515/1.5Y = 1500kv, good for 6s and the coolest setup.
1515/2.5D = 1700kv, good for 5/6s
1515/1Y = 2200kv, good for 4/5s
1515/1.5D = 2700kv, good for 4s, but the warmest setup.

By the way is there a better motor alternative than neu's ?

Depends what you mean by better. There are Lehner motors which are just as good as Neus, but they are 2 pole motors rather than 4pole, which means they will run better on all escs, but they are based in Germany, making them rare to find.

There are also the Plettenberg motors, which are 4 and 6 pole, but they tend to run warmer than the Neus since they have higher KV ratings, and they cost over $300. They are the sexiest looking motors though.

There are the Mega motor motors which are multi-pole inrunners, and they have massive torque, but the case design isnt the best for MT or car use.

And then there are the Align 600XL motors, which are a hybrid outrunner, with an inrunners case design. They are also massively powerful but tend to have a lowish KV rating making them better for high voltage applications, and some escs have trouble starting them, so gearing and programming has to be carefully tuned to avoid cogging.

EDIT: Prices vary, but:

Feigao XL = $60-90
Neu 1515 = $250-300
Pletty = $250-350
Megamotors = $150-200
Align = $150-200

[speedy]

how about those kb.45 motors ? the ones that are 45x63mm and have a 6mm shaft ? 2300kv. aren't that motor more effichent than a 8xl feigao ? it choud have mot tq :) and it's cheap ! 50$