7.4v servo wiring

[tomtom]

Hello,

I've just bought a used KO RSX. I used a KO 2413 with a mini Spektrum receiver (3500) for electro offroad. Without plugging the cap on the receiver, both are working without issue (got an Orion and it needed the cap).
Still, the RSX seems power hungry so I thought about powering it directly from the saddle lipo by cutting the red wire on the receiver side and solder it to the + of the esc.

Does it sound right to you ? :confused:

Any advises against doing so (7.4v power) ?

I planned to use this wiring to avoid any glitches from the servo at full throttle.

Thanks !

[MattW]

There is no need - you'll increase the voltage to the servo, which in turn will increase the speed, and ultimately kill it (all be it eventually).

This is something that people used to do to bog standard servos about 10 years ago, but I haven't ever heard of anyone doing it to a decent servo.

The latest KO servos are very fast, i think you'll make it too fast to even be usable if you run it off full battery voltage.

So for me, it's a no!!

[tomtom]

I thought it was made to be powered by a 2S lipo, so no risk of blowing it.

Thanks for the advise :thumbsup:
I will run it like a normal servo.

[simoncrabb]

The servo specs seem to state it will be fine at 7.4v if that's what you want to do. Massive increase in torque, but hardly anything in speed. Wouldn't be too quick Matt :-)

For 10th off-road I'd be tempted to use is in the receiver with a capacitor if necessary but nothing more.

[MattW]

In fairness, you're probably right in that it wouldn't blow - as many servos are made to run in Gas cars and this often means running off a 7.4V receiver pack. However, it's still a no from me!! Honestly, I know factory sponsored KO drivers that believe their current servos are too fast as it is!! So making it faster doesn't sound like a great idea - or as I say, not something I would do personally - just IMHO of course.

[rsj]

Did you get the response or power version of the RSX?
I have recently bought and installed a High Voltage servo in my 1/10th. The RSX-power was my first choice on spec's but it was a bit over my budget so I settled on a Spektrum S6100 which has slightly less torque. I have wired it direct from lipo as you are thinking of doing and it works well. Rather than cut the servo wires I removed the red terminal from the plug and have connected this to a male terminal from a Y lead soldered into the lead between batt and esc, this way the servo or esc can be removed easily without soldering.
hth

[tomtom]

I got the Response one.

Well, first I need to wait for the new car to fit the servo properly but it seems to work alright without cap. Not as much current draw as expected.

Thanks rsj, one of the first to try it and report. Guess I got to try both (even if the speed increase is a big downsize for me).
My first point was to avoid issues with the receiver.

[rsj]

Think you should be ok on the speed, theres only 0.01s increase from 6v to 7.4v and even then it will only be 0.02s quicker than a 1258.
If it is to quick you can program the servo itself but not sure how you do this, think you need a program card or something? A shorter servo arm would also slow things down a bit if theres room and still enough lock or poss adjust exponential rate on transmitter to slow down initial response. I've done the exponential as it helps smooth out what my over eager thumb keeps doing.
Good luck with the new car

[tomtom]

Thanks !

I run a Vega RB5, the new car is the new RB5WC with a long chassis conversion.