Brushless info

[Gunrock22]

I want to get a BL motor, the problem is I dont know what is good. What are the positive attributes of a BL anyway? They say they have alot a torque, so does that mean I can gear it to the moon? Or are you just paying for efficiency? And what about the controller? The more amps the better? I would like to go above 50 mph, and I was on my way there until I blew my 6t P-94 on 7 cells. Do you think it is possible to go above 50 on 7 cells with a brushless? Sorry for all the questions, I just need to know what Im getting into. Thanx for any info.

[bomb-proof]

Well, weneed to know what kind od vehile you are using.
50mph in a icro Rs4 on 7 cells- no problem
50mph in a e-maxx on 7 cells - problem

[Bob Ebophalus]

u hafta tel us what car this will be in. check out the brushless thread in this forum

[Gunrock22]

I have a xxx-s so I know if it will do 50 with a rs4, then It could definitely do it right?

[Bob Ebophalus]

if u could find enough room to fit all the cells in, yeah u could prolly do 50. i would suggest a very high rpm/volt motor; look for a low # of turns, maybe a hacker b50 5 or 6 turn or a lehner 1920/5t, or another tactic would be getting a not so high rpm/volts and just getting lots of cells, this would give you more torque to pull a higher gear ratio. the second might be better since most motors have a limit of ~50,000 rpm anyways. faster that, you could throw a magnet, this would not be fun

[RCmaniac324]

Originally posted by Bob Ebophalus
if u could find enough room to fit all the cells in, yeah u could prolly do 50. i would suggest a very high rpm/volt motor; look for a low # of turns, maybe a hacker b50 5 or 6 turn or a lehner 1920/5t, or another tactic would be getting a not so high rpm/volts and just getting lots of cells, this would give you more torque to pull a higher gear ratio. the second might be better since most motors have a limit of ~50,000 rpm anyways. faster that, you could throw a magnet, this would not be fun

Actually, most BLs have a solid One-piece magnet, so you can't really "throw a mag"...... that RPM limit stated is the RPM limit of the bearings under the rotational load of the rotor......but basically, blowing a bearing results in pretty much the same outcome, just much more violently: As the bearing blows out, the rotor becomes free at one end at high RPMs. This results in the rotor slamming into the coils at high speed, most likely shattering the magnet and ripping apart the coils, as well as possibly sending shrapnel out the side of the can. This, while bieng catastrophic on its own and potentially highly dangerous to the surrounding parts of the car and anyone nearly, may be accompanied by a fried, smoking controller resulting from the shorted, destroyed coils........

Luckily this usually doesn't happen to this extreme.

Just figured I'd clarify. :)

[PatrickJ]

I cannot figure out how a brush motor can be faster than a brushless. The efficiency of the brushless means more output power. If you run at a higher ampage the brushless will be more efficient than the brush meaning more power so how can a brush out perform a brushless? The lehner 4200 and 5300 are more efficient than the common 6 cells motors and a 1920 or even the hackers are more efficient than the 4200 and 5300.

[RCmaniac324]

Where'd u hear that one from, that brushed motors outperform BL?????? Cuz wherever you heard that from is wrong... maybe under racing conditions, yea, BL aren't better yet, but in all bashing circumstances, they r much better.

[Bob Ebophalus]

Originally posted by RCmaniac324
Actually, most BLs have a solid One-piece magnet, so you can't really "throw a mag"...... that RPM limit stated is the RPM limit of the bearings under the rotational load of the rotor......but basically, blowing a bearing results in pretty much the same outcome, just much more violently: As the bearing blows out, the rotor becomes free at one end at high RPMs. This results in the rotor slamming into the coils at high speed, most likely shattering the magnet and ripping apart the coils, as well as possibly sending shrapnel out the side of the can. This, while bieng catastrophic on its own and potentially highly dangerous to the surrounding parts of the car and anyone nearly, may be accompanied by a fried, smoking controller resulting from the shorted, destroyed coils........

Luckily this usually doesn't happen to this extreme.

Just figured I'd clarify. :)

i heard this explained very well in the bl thread. if it is just the rpm limit of the bearings, why do smaller motors have higher rpm limits than bigger ones? they have much smaller bearings that shouldnt be able to handle the high rpm. he said that the immense centrifugal force would actually cause the magnet to break into pieces, which would exit the windings at very high speeds.

just thought id clarify the clarification:)

[RCmaniac324]

Ya learn something new everyday...and I stand corrected. Thanx Bob for "clarifying" me. :) :p

[Bob Ebophalus]

sure im glad to help if i can:cool: