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View Full Version : Alright I got my choice of my next motor...


Bung-drew
2011.09.06, 08:31 PM
1. Atomic standard BB motor
2. Atomic US standard motor
3. Kyosho x speed

I just need to know how each of those motors perform in terms of torque and speed based on my batts and gear ratio,running orion 900s and 9T/54T pinion and spur gear...LET THE FEEDBACK BEGIN!:D

EMU
2011.09.06, 08:51 PM
Atomic Standard BB motor will be the fastest of the group. Due to the low ratio you state (9/54t) I would definitely recommend this motor over the others. With a slightly larger pinion (10 or 11) it would be perfect for almost any track.

All three motors are speed motors, meaning that they dont have much low end torque, but have good RPM. The ATM US motor should have the least RPM, but most linear torque curve. The Kyosho X-Speed will have a little more RPM than the US, but less than Standard BB since it is about a 50 turn motor, while the standard BB is a 48t. The less turns, the higher RPM. The Standard BB is also the only bearing motor in the mix.

Batteries dont have too much to do with it, most 750-900mah rechargeable batteries are close to the same performance. The difference is marginal.

Bung-drew
2011.09.06, 10:12 PM
Thanks for the info EMU,I would also like to know how to make my ride run quiet without that high pitched "whine" when u gun the throttle?

herman
2011.09.06, 11:51 PM
i've read somewhere that the special spur/pinion gear with the different pitch 64/126 pitch (by pn) are much quieter...

http://www.kenonhobby.com/assets/images/2WD-Gear-Ratio.jpg

color01
2011.09.07, 01:57 AM
Brand new pinions and spur gears run the quietest. :) 64p and PN 126p gear sets are both very quiet when brand new, but the 64p gears will eventually make some noise while the 126p gears stay quiet until they break. To an extent I like having a little bit of noise, if only to tell how the car is doing -- if you want to run the 126p gears you have to be a little more vigilant about maintenance and visually making sure the teeth aren't worn out, because the sound isn't going to tell you a whole lot. Hope that helps. I'm currently running the 126p gears. ;)

unearthed name
2011.09.07, 02:28 AM
get the 126 pitch spur/pinion drew. be careful. they're fragile. improper gear mesh will damage them

Bung-drew
2011.09.07, 10:24 AM
Well that will mean I will have to get a ball diff,unless they have replacement spur gears that can fit my current gear diff=P

cowboysir
2011.09.07, 11:29 AM
If you have a gear diff you may want to check that ratio again...I don't think there's a stock gear diff with 54 teeth.

Atomic BB standard is my favorite of the three on stock asf fets.

Bung-drew
2011.09.07, 03:19 PM
Since the atomic BB motors can fitted with ball bearings,I am assuming this motor is the coolest and least current draining among the 3?

EMU
2011.09.07, 05:11 PM
I think it drains the most current out of the three listed... It has less turns/winds, so it has more RPM.

After reading though other posts, I see that you are using a gear diff? That would make your gear ratio 9/44, not 9/54 as previously stated. All three of these motors will be overgeared at that ratio for most tracks. An 8/44 should be good for all of them.

Bung-drew
2011.09.07, 06:26 PM
Alright I think I shall go with the US standard motor due to it's more linear torque curve as u mentioned,meaning a good balance of torque and RPM? Any benefits in terms of punch etc?

EMU
2011.09.07, 09:20 PM
The US motor will be slower than the Standard BB. Similar curve of power, just considerably less power. The US spec motor I think is 60t, so it goes between the power of the stock motor and the x-speed, but closer to the X-speed... Standard motor is faster than the X-speed.

herman
2011.09.08, 02:10 AM
nice to hear that you're going to keep it stock... :D
actually i kinda like the whrrring noise coming from the motor too...

i've read somewhere that even numbered pinion gears sound quieter than odd numbered pinion gears or was it the other way around? (i.e. 6t,8t is quieter than the 7t, 9t)...

haven't run my cars in quite a while... and don't really know if this is really true... can anybody attest to this?

sometimes when they're noisy, there is usually some dirt in between the teeth on the spur / pinion gear... so don't forget to brush your teeth regularly... that way they don't wear down that easily... :D

color01
2011.09.08, 02:35 AM
Hard to tell, and I doubt it. :p 13t and 14t (64p) sounded the same to me, as do 27t and 28t (126p -- well, there's hardly any sound here).

It is true that theoretically you can get weird harmonics if the spur/pinion ratio is nice and round (say, 6/42, 7/42, 11/44, 13/52, etc.) but I think our gears are light enough that they don't really have enough inertia to resonate much. :)

Bung-drew
2011.09.08, 03:12 AM
Alright I'm probably going to get just the standard BB motor for now...the guys at atomic collectives have gave me their recommendations:)
I will also intend to get some grease for my gear diff,I'm gonna try tamiya mini 4WD gear grease,amazing stuff for these little cars should work well on mini z gear diffs too.:D just gotta try this out lol...almost forgot, a smelly new set of...(make a guess?)

EMU
2011.09.08, 04:19 AM
The 6t pinion is a little noisy because of how few teeth there are, and how great the angle between the teeth is. Typically the larger the pinion, the less noise it will make since the gears will mesh better as they rotate. 7t uses the same shim as 8t, so its a little loose and makes a little noise. 8t and 9t are the quietest of the stock pinions and motormount/gear diff combo... With an aftermarket mount with fine adjustment for gear mesh, the difference between 7t and 9t noise is marginal. The gear diff resonates the sound more than the ball diff, so it is more audible.

When I drove gear diff, I used grease for looser less grip surfaces, and no grease for higher grip surfaces. Looser surface = tighten the diff action, higher grip = more free diff action. With a ball diff, you can dial in a little slip, so its sort of reversed if you use the diff as a slipper, which is not recommended.

herman
2011.09.13, 01:51 AM
thanks again for the info e... :D