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Why does weight matter?
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E-Maxx King
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Why does weight matter? - 02.06.2008, 04:35 AM

Lets just say if you had >


3.3 revo 8xl #3 with truggy tires Can you use the two speed?
Truggy 8xl #2
Buggy 8xl #1

Y cant you get a revo to do 55?

Last edited by E-Maxx King; 02.06.2008 at 04:49 AM.
   
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suicideneil
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02.06.2008, 07:46 PM

Simple, the motor is only capable of pushing upto a certain 'load', that is, a certain weight of vehicle with any given gear ratio. The Revo would be the heaviest of those setups you suggested, hence you can only gear so high before the motor starts drawing too large of a current = fried esc and cooked motor. The lighter the vehicle, the higher you can gear because there is less of a phyiscal burden on the motor. Same reason why having lightweight wheels & tires is better, since the vehcile will excellerate quicker and put less of a load on the motor = less rotating mass (fly wheel effect).

If you want the truck to go faster, you need a larger motor like a Neu 1527 or something comparable, basically something capable of producing much more torque which allows for higher gearing for the same current draw, or something along those lines anyway.
   
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E-Maxx King
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02.06.2008, 08:12 PM

So you can push it to keep up with a truggy. You just need a bigger motor. K thx. Got it now.
   
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zeropointbug
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02.06.2008, 08:17 PM

Yes, the heavier the vehicle is, for a given speed, the more power it takes to move it around. None of the Feigao motors can do 55mph in a Revo 'reliably' (heck, it can hardly do 40mph reliably)... although, a 1515 Neu could do it, my 1512 can even do it, and the temps are still under 180F.


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BrianG
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02.06.2008, 08:21 PM

Yeah, just think of real 1:1 cars. You wouldn't put a typical 2.0L 4-cyl in a F250 pickup (and I'm not talking turbo/super-charging here). The weight and power requirements would overwork that tiny thing! You could make it work, but you'd have to gear WAYYY down, and then your top speed would be about that of a moderate jogger.

It takes power to move something. The heavier that something is, the more power is needed. Does it take the same force to push a bicycle as a Ford Taurus? Nope. Same thing here.
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E-Maxx King
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02.06.2008, 09:50 PM

so a 1521 is more of a mt size motor? Does feigao make a xxl?
   
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jnev
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02.06.2008, 09:59 PM

The 1521 would be a beast in a MT like the Revo (in a good way). You will have more than enough power. It should be able to reach 55mph if you choose the right gearing and voltage to run.

I have heard about Feigao making an XXL motor, but I have never seen it or anything....


   
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BrianG
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02.06.2008, 10:01 PM

Not sure about the Feigao question, but the 1512 has about the same power as an XL motor just judging by feel, and stays cooler (better more efficient motor). The 1515 is even more torquey, and the 1521 even more so. Better stock up on diffs or get the hybrids for your Revo if you get any of the bigger motors.
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crazyjr
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02.06.2008, 10:39 PM

my 1515/2.5/d is too much for my G2R with 5s, but thats what makes it fun


Work because i gotta, play because i wanna

People here hate Nitro, I love it. I start it, run it about 50 ft from me and it dies, I go after it. Perfect exercise
   
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E-Maxx King
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02.06.2008, 11:34 PM

What do you mean? The only way to get to those speeds is to get a BIG motor then program the esc to take some of the bottom end out?
   
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entjoles
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02.07.2008, 12:32 AM

i dont know about the others , but with a mm esc. the punch control can be adjusted to ease into the power
   
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zeropointbug
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02.07.2008, 01:26 AM

Let's look at this face value... many of us with some experience with these things; can tell you that you do not want to be going 55mph in a MT.

I have tried it with my 1512 Neu motor (1512/3D on 7s2p A123), it was awesome for the first few passes at speed, but after that the fun disappears and fades to being mildly boring. It is also FAR to stressful 'trying' to control the truck at these speeds... it is "guaranteed" (mark my words) that you WILL crash at some point, and severely damage the trucks equipment.

Second, if you REALLY want to do this, you only need a 1515 (you can do it with a 1512, but 1515 would run cooler, and more torque at those gear ratios).


“The modern astrophysical concept that ascribes the sun’s energy to thermonuclear reactions deep in the solar interior is contradicted by nearly every observable aspect of the sun.” —Ralph E. Juergens

Last edited by zeropointbug; 02.07.2008 at 01:30 AM.
   
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