lbenton

iTrader: (48)

Some esc's have it, and there are external options. But my question is would it be best long term to simply run a direct wire from the 2S lipo to the radio/servo?

No more brown out worry with high demand servos.

Not using internal BEC on the ESC will in theory cool that down a little bit.

Why is this not a normal practice?

Seems like it would be as simple as it is effective.

King DORK

iTrader: (53)

Unless the servo and/or receiver are rated for 8.4 volts it's probably not a good idea. A peaked lipo is 8.4v.

Randy_Pike

iTrader: (6)

Back in the "good 'ol" days that was a common practice.

There's really nothing wrong with doing that as long as your servo is rated for the 8.4v.

Dave H

Some old school Tekins provided a power wire for this purpose, provided full pack voltage. Some KO servos had an extra input wire to hook up this way too.

There are those who suggest the voltage change over a run, and thus inconsistent performance is an issue. Never noticed it myself, your mileage may vary.

ufoDziner

iTrader: (39)

For these and a other reasons, I run a 300mah receiver pack in each of my cars. I don't think it's common because it's less convenient. Here's my 4wd:

rcjunky1

iTrader: (10)

In 1/10 its not needed and more wiring for a BEC. With the new tekin stuff with HV BEC's built in it may be more common.

DjAlusiv

I run an external BEC with my Tekno 410. It is cheap and provides flawless power. It really just drops the voltage and provides a cap. With the power in my lipos there is no need to host an additional battery.

Badger5

For me one of the advantages of this could be that high current draws are not routed through the receiver. I know modern receivers are very good and rarely give trouble but I have had experience where a high powered servo caused the servo wire connector in the receiver to become brittle from heat. I just get the feeling that modern servos could be drawing more current than the servo and receiver wires and connectors should be taking.

Perhaps in the future we will see speed controllers with a separate supply for the steering servo?

Davidka

iTrader: (86)

Unnecessary. The servos causing brown outs are poor quality, not "thirsty", unless we're talking about 400iz. 1/5 servos. With servos appropriate for up-to 1/8 racing it's a non-issue.

lbenton

iTrader: (48)

I thought the "High Voltage" style servos were designed to run on a direct feed off of 2S lipo. They are rated at 7.4v but I would think that if the idea was to be lipo powered they could handle the 8.4v fresh off the charger deal also.

Davidka

iTrader: (86)

That is correct. Their original purpose of them was for 2s lipo radio packs in nitro vehicles. Racers seem to want them because they have more output torque, but that's unnecessary for most applications. 200oz is all that is needed for most classes of racing. We've had servos that powerful at 6v for 15 years or so.

TY@TEAMTEKIN

I think it has more to do with servo speed than torque in 1/10 applications. A fast servo definitely doesn't hurt.

lbenton

iTrader: (48)

The way I see it, strong is easy to find... but many of them are sluggish. A good HV servo has a lot more snap going back and forth.

My current project / agenda is to migrate all my cars to 7.4 servos that have ample torque and a .11 or less time.. (seems like breaking the .1x barrier has a price jump to it as well as a more of a torque sacrifice)

DjAlusiv

So this would include Savox and Hitec then? I have had brownouts with both of them when not running external power. Of course castles internal BEC is not the greatest either.

thecman26

iTrader: (112)

With a little research you can find many servos that will meet your requirements and do it on standard BEC's...

http://www.servodatabase.com/

FWIW: In 1/10th scale an external BEC is not needed at all.
Here's a good suggestion: @6v 168oz & 0.09s
http://www.amain.com/product_info.ph...tal-Gear-Servo
All that for $50, highly unlikely to be matched in a HV servo for as much $$$...