Overkill? 30kg/403oz servo

[wallot]

i need at least 18kg servo for my heavy truck with bigjoes on commandos

I have Proline Steering kit
The new JR looks very good but it might be overkill.

DS8711 ULTRA TORQUE SX
Specs
Type: Digital Ultra Torque
Torque: 347 oz/in @ 4.8V, 403 oz/in @ 6V (30kg@6V)
Speed: .19 sec/60° @ 4.8V, .15 sec/60° @ 6V

Milder version

DS8611A Digital Ultra-Torque MG Servo
Torque: 260 oz/in @ 4.8V, 320 oz/in @ 6V
Speed: .18 sec/60° @ 4.8V, .15 sec/60° @ 6V
Gears: Alloy w/ metal/nylon B1 gear

Or the classic Hitec HS-5955TG
Speed: 0.19 / 0.15 sec @ 60 deg.
English Metric
Torque: 250 / 333 oz.in (4.8v/6v) 18.0 / 24.0 kg.cm
Size: 1.57" x 0.78" x 1.45" 40.00 x 20.00 x 37.00mm
Weight: 2.18oz 62.00g

Weakest and cheapest

Motor Type: Coreless
Bearing Type: Dual Ball Bearing
Speed: 0.24 / 0.19 sec @ 60 deg.
English Metric
Torque: 200 / 250 oz.in (4.8v/6v) 14.4 / 18.0 kg.cm
Size: 1.57" x 0.78" x 1.45" 40.00 x 20.00 x 37.00mm
Weight: 2.18oz 62.00g

Or am I just crazy and Futaba S9351 High Torque will do?
FUTM0236
Volts Torque Speed
4.8V 153.0 oz-in. 0.16 sec/60°
6.0V 192.0 oz-in. 0.13 sec/60°

I just cant decide. JR servos are supposed to be one of the best.

[BrianG]

Personally, if money were no object, I'd get the strongest one if you have a high steering load. Also, be aware that the higher torque servos will require more power from your BEC; I wouldn't be surprised if that 403oz-in servo can take 2-3A average with 5-6A peaks.

[Mike.L]

333oz of power will be enough.

I run a JR Z9000T in my Muggy with 40 series Mashers. My servo puts out around 300 oz/in. or torque. It does the job, although I don't think that a 400 oz/in servo would be overkill. Just make sure that your BEC can keep up with the current draw.

[wallot]

UBEC can handle 3A cont. with 5A peaks. I dropped JR email asking for detailed specs of the DS8711.

Can reciever handle so high current going through?

[BrianG]

It would depend on the thickness of the traces on the PCB, but I would say yes since they are kinda short. I would also keep the servo wire short to reduce resistance since it is pretty small wire.

[wallot]

would it be ok to do connect servo directly to UBEC? (+ and - to UBEC and - and signal to reciever) of course UBEC to reciever as well :)

There are ubecs that can do more than 3A continuous. They just cost a lot more.

[MetalMan]

I am quite happy with the Hitec 5955-TG I have in my Revo. It turns the tires with lots of authority. And it helps that I got it brand new for $75 (my employee price is $82).

[crazyjr]

^^ same here

[BP-Revo]

I would have to vote for the 5955TG. I have one in my G2R and its plenty.

Also, even though JR's new servo has a whopping 400oz+ of torque, it has "just" metal gears. In my opinion, once you hit the ~200oz mark, you really need Titanium gears, and thats just what the 5955TG has.

The 5955TG should pretty much outlast your truck.

[wallot]

As I am still bit afraid of Hitec reliability a decided to go for 320oz JR 9000T - all gears metal

the 8611A is AIr version thats why one gear is plastic.

[Serum]

LOL! I guess this poll was quite useless then.. Look at the results /posts and what you bought.. :)

The hitec has got tough gears.

[wallot]

well the Z9000T has same parameters as HS-5955TG so everyone wins :)