MBX6T: more steeringpower

[Gv288]

Hi, currently I'm running a MBX6T CC2200kV Mamba max ESC on 4s 6500mAh
With Mike's conversion kit. I have heavy Maximizer Beadlocks on it with, again, heavy 40-series Mashers.

My current steeringservo is the HITEC7955, which puts out 24kg (333 oz./in.) torque on 6V. After doing some research it seems that the ESC puts out 5.1V to the servo. So I have effectivly 24kg x 5.1V/6V = 20.4kg (283oz./in.) torque (is this correct?)

Anyway, it's not enough. So I can go for an external BEC, but I'd rather not.
So I'm looking at this servo: Hitec 7980
http://www.hitecrcd.com/products/dig...hs-7980th.html

Which put’s out: 38kg (500oz./in.) on 6V, does this mean: 32.3kg (425oz./in.) on 5.1V?
dimensions: 43.69 x 22.35 x 39.88mm (1.72 x 0.88 x 1.57inches)

The questions: is my reasoning correct on the torque VS volt, and will this servo fit Mike's conversionkit??
Thanks

[Arct1k]

You need an external BEC... a 7980 is a larger servo and wont fit in without new posts etc. Its also a HV servo so needs 7,4v ie an external BEC

In between you have a 7950 which is normal size but also needs 7,4v and an external BEC.

I'd start with an external BEC set to 6.2v with the 7955 and go from there.

[j.f.s]

I know this isn't what you were asking but I got real curious. :)

I'm running a 6T with a Savöx 1256TG //Torque(@4.8V oz-in): 222.2 or 16kg, Torque(@6.0V oz-in): 277.7 or 20kg// which is plenty even with 40 series tires.

Mine can turn the wheels fine and if I hold the tires the servo saver will do it's job. Servo will turn to it's end points.

Are you sure it isn't you're servo saver being set too loose so that the servo is turning and the servo saver engaging prematurely?

[Gv288]

That's actually a very good point, I'm going to check that tonight.
I'm allready very addicted to this hobby, but still learning a lot every day, Thanks.

Any guidelines on how strong the servosaver should be set?

[j.f.s]

The default setting is 4mm between the adjustment nut and the chassis IIRC. I believe mine is set to 6 or 8mm.

Forgot to mention that I use an external BEC, the Castle 10A version, to save some load from the ESC. The Savöx servos are known to be amp hungry. I believe the MMM BEC provides 3A max.

[swiftneed]

I have bothe servos the savox and the hitec one on the xray xt8 and the other my mbx6t and they turn just fine with both servos and dont have steering problems with any tires including beadlocks

[SV6000]

I too had similar steering servo issues, the fix was not a bigger servo but an external bec. The internal bec on the MMM does not give enough AMP to run the higher torque rated servos.

[Gv288]

Problem solved: it was the servosaver, set way too soft
(it's my first MBX6 and I bought it secondhand)

Everything running smooth now:

http://www.youtube.com/embed/9aO8NpQPSkY?hl=nl&fs=1