e-maxx 3905 motor question
 

Hey guys im going to bought a 3905 e-maxx and I need to know I got some brushless motor in my hands but I cant use it all dont have proper gearing pinion for it ... so I got a :

feigao 8xl

neu 1515 2.5d 1700kv

neu 1509 2.5d 2700kv


I dont have any gearing on my hand for run the neu 1515 2.5d 1700kv how about running the neu 1509 2.5d 2700kv ? it is enought torque for push it without overheating @ 4s on mamba max esc with bec disabled ? here some config :

Differential Ratio: 2.8461538461538463
Transmission Ratio: 1.8333333333333335
Other Ratio: 1
Spur Tooth Count: 68
Pinion Tooth Count: 17
Total Voltage: 14.8
Motor KV: 2700
Tire Diameter (inches): 5.5
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor coil Ω: 0.0082
Spur/Pinion Ratio: 4 : 1
Total Ratio: 20.87179 : 1
Tire Circumference (inches): 17.28 inches (438.88 mm)
Total Motor Speed: 39960 RPM
Vehicle Speed: 31.33 mph (50.32 km/h)
Effective KV Value: 2700
KT constant: 0.5 oz-in/A
Motor Torque: Amperage not specified...
Final Torque: Amperage not specified...
Final Power: Amperage not specified...



NEU1509F/S
1000 Watts Continuous
2000Watts - 30sec
Max rpm: 60,000
Stator Dia. 1.5"
Magnet/rotor length 0.9"
Shaft: 5mm
Shaft length: .75"
Weight, S 212g, F 225g
Dimensions 2.1"L x 1.56" dia.

Mamba maxx isnt really for 1/8th scale, I'd look into a MMM. And yes, it would be enough torque but I would be watching the ESC temps very closley..... I would gear 19/68.

do you think this motor would fit the stock e-maxx motor mount ? since it has large diameters ..

I suppose you could use it, it's a higher Kv. unit, so there will be higher currents happening. Sure you can get alot of power from it, but it will heat up after a short while geared too high. 5 years ago, ppl would have thought the 1509 was a great motor for MT's... not anymore, 1515 is the standard, and even then things heat up for some setups, some ppl even moving on up to 1521.

I am running a 1512/3D (1700Kv) on 6s, when geared for 40mph, it has tremendous power (mostly on part of batteries), upwards of sucking 2300 watts from the pack! Temps are usually around 150 - 160F hard bashing...and 120 - 130F when racing at my local track (geared for 36mph), even after a 30 minute MAIN. Those temps actually surprised me, I was expecting much higher!

EDIT: Sry, this is in a BL Revo 3.3

Well, all 1500 series have a Dia. of 1.53". Yes, it will fit with the stock motor mount. You will find that a number of people here have Neu 1500 series in their emaxx's.

finaly im going to use a 20t pinion I forget the maxx are 32p.

and for the e-maxx does the driveshaft diff and tranny last a long time ? on my slash @ 3s I will destroy driveshaft and yokes so much fast

Yes, the emaxx is brushless ready. The drive shafts occasionally brake and that is normal unless you have steel ones. I am putting together a VXL slash right now, how often does yours break?

the driveshaft and yokes on the slash are not so durable @ 3s ... you will need spares for sure im currently using the stampede steel yokes still going strong and I tried too jato driveshaft plastic on the slash and still the same then the stock nothing would work better them the FLM CVD for the slash is the way to go for 3s & more ...

I changed my mind I bought a e-revo instead of e-maxx the wheel hex are 14mm right what about the stock tire diameters ? do you think the neu 1509 2.5d 2700kv would push it without any troubles on 4s with mamba max esc also ? and does it fit on the stock revo motor mount since its larger .. ?

The stock revo mount is the same size as the emaxx's. I would suggest getting a single motor plate @ cover for it. Again, yes it will be able to roll it forward but a MM and a 1509 are not a good choice for large trucks like these. If you have the $$$ then I would purchase a MMM combo or with a Tekno Nue then it will fly with no problems. If you do chose the MM with a 1509, watch the temps carefully. Since you are interested in the MM esc in a revo, take a look at this:
http://therccarblog.com/2008/07/29/t...ildup/#more-17
Cheers!

the stock e-revo tires are 5.9" or 6.10" diameters ?

5.75"

If you have the 8XL and a 1515 2.5D why not run one of them instead of the 1509? If your buying the truck then you have money to spend, why not spend another couple bucks and get the right gear? Pinions might be a bit costly but the spurs are cheap. By the way, if you look through the general discussion section, I have 3 32p 5mm bore pinions I'm trying to get rid of, PM me if interested. I have a 20T, 2T, and 25T