47yok

Stock servos. Read in an earlier post that the stock servos can run on 7.4. Rx only supplies 6 volts. The servos have more power. I figure the 1.4 volts is almost 25%.
So that should be a healthy increase maybe.
Just trying it out. If it doesn't work I'll get another servo. I already have 1 hs7954sh which does 403 inoz at 7.4. I'll just get another or try switching the servo savers to the mgt springs. Supposed to be stiffer.
See what happens.

47yok

This is how I adjusted the throttle curve last night.
Worked very well.

47yok

Just plugged it in and checked. No smoke tonight.
Then it on and tried steering. Pretty snappy now. I the servo savers being upgraded will help more also. Gotta go. Lipos to run out. Yippee!!

Overdriven

iTrader: (18)

Servos don't have to be power hungry to see the benefits of an external bec, as long as it's more capable than an esc's internal bec. Any Bec is just a power source and like any other power source there will be voltage drop under load. I once hooked up a multimeter to measure the amp draw of a servo while sawing the transmitter wheel back and forth. I saw an average draw closing in on 1amp with spikes up to around 1.5amps. Even on a 5amp rated bec your going to see the normal 5.5v it puts out drop lower under load. Strap on a 10amp bec and the voltage will drop less because it can put out more amps. Raise the voltage and your going to draw less amps, Ohm's law, wattage = volts multiplied by amps. Any load, servo, motor, etc is going to draw a certain wattage. Divide watts by amps and you get voltage or vice versa.

It's not scientific but my nephews LST had LED's on it plugged into the receiver and they dimmed a lot when you steered. With a Castle 10amp bec set to the same 5.1v the MMM esc puts out the LED's dimmed less because the external bec is capable of more amps so voltage under load doesn't drop as much. With the external bec set to around 5.7v the LED's didn't dim at all and servo performance was improved. I eventually settled on 6.3v for that truck to keep from burning out the LED's and the servos liked it too. More voltage equals less amps drawn. A bec may be rated to 5amps or 10amps but that's the max, doesn't mean voltage won't drop when you try to draw that many amps. That's the part nobody tells you.

RX doesn't supply 6v, it supplies whatever the esc's internal bec puts out. In the case of the Sidewinder8 esc that comes with the XXL2e that's 5.5v. BTW the receiver can pose a power restriction to the servo(s) if they're trying to draw enough. This is usually only an issue with high power servos, multiple servos and/or a heavy vehicle. But the harness you were using was initially made for 1/5 for this very reason to ensure the servos get all the juice they need without any potential power restriction of running servo power through the receiver.

Edit: Glad everything worked out for you in the end.

themanwithnonam

ah ok, missed that. I have the mgt springs and it made noticable diffrence.

themanwithnonam

I don't want to start a fight about this, but Ohm's law is volt = current x resistance. Let's call it's V = IR if you think of the servo as the resistance it simply states that when you have higher voltage it will draw more amps not less. if the resistance is i.e 2ohm

1) 7.4V = I x 2 => I = 7.4/2 = 3.7 Ampere
2) 5.5V = I x 2 => I = 5.5/2 = 2.75 Amps

I see it this way -> With a higher voltage the wheels will turn in say 0.5 secs
With a lower voltage the wheels turn slower in, lets say 0.8 secs the wattage used to turn the wheels may be the same as watt is defined as energy over a period of time. But in order to turn the wheels faster more juice (amps) is needed and it's possible to draw more amps with a higher potential. (Volts).

What I'm trying to say is

High voltage = more amps drawn a shorter period of time
Lesser voltage = less amps drawn over a longer period of time.
The same amount energy (VxI) is used measured over time.

47yok

How difficult is it to swap those springs?

themanwithnonam

Very easy but I only done it once 3 years ago. If I remember correctly you buy the mgt servosaver and use the stock servo arm(s). Not sure if the mgt came as a kit for all splines or if you needed to buy the correct version for your servo?

themanwithnonam

Some more info here

http://www.rctech.net/forum/monster-...ng-servos.html

EDIT: Even more info: http://forums.thetoyz.com/index.php?showtopic=7755

47yok

I think it was an old post of yours. It was in with the one doing the single servo mod. Looked into that but 2 of the links posted aren't any good.
So couldn't find 2 of the parts.
Then read your idea. I like it. It said to use servos from the mgt.
Thanks.

47yok

Thank you.

themanwithnonam

jr version being discontinuned apparently?
http://www.amainhobbies.com/rc-cars-...sc25167/p27218

47yok

The xxl2e has spektrum 601 servos in it now. I'm trying to find spline count. Then I can order the mgt saver.

themanwithnonam

Spektrum is rebadged jr's or savöxes - I would guess the ones in xxl2 is jr's? Hence, 23 spline. Please verify once you find out for sure what it is.

47yok

Yup this is what I found out from 2 different places. Rebagded Jr's and 23t.