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-   -   7xl specs? (https://www.rc-monster.com/forum/showthread.php?t=1528)

MetalMan 11.10.2005 09:46 AM

The motors in a series, like all of the L motors, for example, are rated the same in terms of power. At their rated amperages, they should in theory all have the same torque. But, they will all have different torque constants, with the fastest motor having the lowest torque constant, which is why it pulls all of those amps.

Serum 11.10.2005 01:51 PM

not entirely true metalman. It's the power of the magnet that decides what power the motor can put out. The copper normally isn't the limiting factor.

Serum 11.10.2005 02:00 PM

It's brushless, think different.. :p the energy that is needed to turn the shaft around takes more energy with a higher KV rated motor, than with a low kv motor. it takes more energy, because the magnet give the resistance to the magnetical field, because of this magnetical field moving faster with a higher KV number, the amount of energy is the same if you calculate is back. the torque stays about the same. it's the current and the rpm's that differ.

Serum 11.10.2005 02:10 PM

The reason why i got to this;

My plettenberg bigmaxx made wheelies with the savage on 16 cells. It did the same wheelies on 8 cells. because a motor can't deliver more power in a certain rpm range, because of the limit that the magnet/magnetical field has got. with this high eff. motors, you are in this limit. (otherwise you would have got a motor with 100% + eff.)

Serum 11.10.2005 02:26 PM

You can see ALL motors from the same range, loosing their efficiency at a certain point (it all is at the same point of torque they need to deliver) they all suffer a sudden eff. drop.. (they start getting hot at this point, which is a logical consequence)

reason for this is the statisfaction point of the magnet. and that is what i'm talking about. ALL motors from a certain range can deliver the exact same torque. Question is ; have you got the A's to feed the high KV monster... :D

Basketti 11.10.2005 05:18 PM

So the lower the number the faster it can go, the more rpms it has(7xl is faster than a 9xl), but they have the same amount of torque.

So whats the point of having a 9xl if the 7xl has the same amount of torque and is faster?

Serum 11.10.2005 05:32 PM

Runtime. and the max current the batteries can deliver. and the fact that the 7XL might be too hot for the setup (like running 20 cells on it, it takes a 8 or 9XL to do so)

Basketti 11.10.2005 06:22 PM

oh ok. so the 9xl has more run time than the 7xl, and it can also handle more cells than the 7xl? i see:). thanks for clearing that up for me :).

I might get a 7xl and a 9xl when i go brushless and use the 7xl for bashing at the park and doing jumps, and use the 9xl when im at home or dont need the extra speed but will be nice to have extra run time. good idea or not?

squeeforever 11.10.2005 08:02 PM

why not just an 8xl. alot cheaper.

coolhandcountry 11.10.2005 08:15 PM

Why not just gear the 9xl up to do your jump and such? Unless you trying to jump a house. :D It has some good power and run time. Just a thought. A 8xl may be a good choice. I have not run a 8xl so can't help you there.

Basketti 11.11.2005 12:53 AM

Jump a house, hmmmm maybe lol. i'll try and jump the carport first lol.

how much difference in runtimes and speed is there between the 7xl, 8xl, 9xl?


coolhandcountry 11.11.2005 10:25 AM

9xl 25 min 16 gp 3700 can tell you after the weekend on the 7xl. same truck.

Basketti 11.11.2005 06:23 PM

wow 25mins thats cool. were you going slow or going pretty hardout?

Im gonna use 16 ib3800 cells so it should be about the same as what your getting with the gp3700's.

oh and another question, i read somewhere on here that the bearings in the 8xl and 9xl can handle more rpm? why dont they put the same bearings in the 7xl cause its a faster motor?

squeeforever 11.11.2005 06:43 PM

well not really sure about the bearings on the 8 and 9xl but i would spend the extra 10 bucks and get the wanderer. its got better bearings than the feigaos. basically the same motor though.

Basketti 11.11.2005 06:54 PM

oh yeah that was it, mike was getting the wanderer 8xl and 9xl and they have better bearings. i think i'll get a wanderer then.


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