[txaggie08]

I'm assuming(don't have one in front of me) that ESC on the SCX board is based off fets correct? And these fets are why there is an RPM or turn limit on the motor capable of running...

Why not do what Mini Z and xmod guys have been doing for years and stack the fets to improve performance?

Here's a tutorial: http://www.atomicmods.com/Categories/Tutor...T-Stacking.aspx

Has this been tried and failed, or do I need to go break out my fine point iron and order some fets

**edit**

Looking at the board we're putting an awful lot of voltage through a single fet. The mini-z and xmod boards, stock, run a lot lower voltage on aprox the same can size......with 2-4 fets....stock.... no wonder they're burning out.

 

[Brett Davis]

Looks like a good idea, still waiting to get the cash for my set but how long do the chips usually last with normal use?

The description ruined me straight up with "requires advanced soldering skills"

patience I have though

. With a bit of practice though I would give this a go but at the moment I have never soldered anything.

But it looks like it could work don't know if anybody has tried, but I am pretty new here though.

Brett

 

[txaggie08]

Life span should be very long.....mos fets are driving pretty much everything now, from amps and radios to speed controls....... any power handling.

The more you have, the more power handling you have.

"advanced" is a relative term. There's four very small solder joints to make....CAREFUL is a better term. I'm going to order some fets this morning I think.

 

[Brett Davis]

let me know how you go

Brett

 

[txaggie08]

I ordered 4, I'm hoping two might allow a 21500 motor to run well. it will come close now, with about 2/3 again the power handling capacity(the estimate I've read from the mini-x crowd), it should be good.

Most of the people I run with enjoy speed. We like lane changing strategy, but doing it at a higher speed.

 

[LDFan]

There are two reasons why this is a bad idea.

1) The position of the FET is on the bottom of the digital chip and if you try to stack it you will not be able to mount the chip to the chassis due to the increase in height. Of course, you can still double it up but you'll have to utilize wire jumpers to place the 2nd FET in a remote location.

2) Remember that there are FETs' in the Pit Box / Control Unit that provides the power for the cars to run. If you increase the amount of power that the digital chips will draw, you will also be over taxing the Control Unit and probably blow it in the process (especially if running six cars w/ doubled up FET's). Now, if you intend to do something like a Simple H mod to the Control Unit and thus give it greater power to compensate, then no big deal but unfortunately no one that I know of has done this yet.

Finally, I've had my SCX-D system now for about four years and in my opinion (as well as my fellow racers), we prefer to keep the speed the way it is with the standard RX-42 motor. The reason for this preference is all about what digital racing is all about; strategy employed w/ lane changing. The whole idea of racing digital is to navigate yourself amongst a crowd of competitors and find a way to get the best line to win the race. Having an all out speed war doesn't play well in this situation because you've just reduced the amount of thinking time needed to form a strategy and next thing you know everyone is crashing. And with everyone crashing, a sense of rhythm can't be established to have a good competitive race. For analog racing, you can go as fast as you want since the strategy there is simply speed and handling w/o any worry of hitting anyone.

Obviously, I expect some to disagree with me on my take for digital and that's okay. It's just my two cents.

Dave

 

[txaggie08]

I knew that answer was coming. This is about what it's about for everyone....as I said, we enjoy the extra speed and acceleration. To me , it requires more thought, more planning, to run faster more consistently. At some point you physically cannot take a turn at any higher rate of speed, therefore requiring the large motor down the straights to make it any faster. Just my .02$, Not everyone runs/thinks/does things the same way.

I do not foresee major issues with the control unit. as I understand the system, at this point it's putting out FAR more power than the cars would have to have, the weakness is in the car itself, not the power provision. There are individuals running 6 cars with 21500 motors in the now. The car is the failure point.

I have no real plans of mounting these in stock SCX cars, but rather using them in the much nicer slot.it units.

 

[LDFan]

I hope you're right.

In any case, keep us updated on your progress.

Thanks,

Dave