Does anyone have experience with the high-torque HS-7975HB or the high-speed HS-7966HB? They specify extremely fast speeds of .14 seconds and .10 seconds on 4.8 volts respectively.

These servos are about the same price ($45-ish, Tower Hobbies) as the seemingly popular HS-5645MG/HS-5625MG "toque" and "speed" servos. Their specified transit times are .23 and .17 respectively, on 4.8v.

I'm guessing metal gears are stronger than Karbonite gears... whatever Karbonite is... but does anyone here have a word against the faster Karbonite servos? I'm looking for a servo to go into a Rustler and then possibly into a Slash 4x4 at a later date. Gotta love those Tower Hobbies "we miss you" 25-off-50 coupons!

the karbonites aren't metal, but they are supposed to be a lot better than stock.... i have a karbonite geared servo in my rc18t, and i bash the heck out of it... haven't had any problems

I have the HS-7975HB. Go with that for 2WD SCT or your Rustler, etc. About 150 oz of torque, .10 time, its perfect for 2WD. The other is a little low on torque and high on speed. Your voltage is wrong though, to get 144 oz torque and the .10 sec time you have to run it at 6.0 v vice 4.8 v however.



Control System: +Pulse Width Control 1500usec Neutral
Required Pulse: 4.8-6.0 Volt Peak to Peak Square Wave
Operating Voltage Range: 4.8-6.0 Volts
Operating Temperature Range: -20° to +60° C (-4°F to +140°F)
Operating Speed (4.8V): 0.13sec/60° at no load
Operating Speed (6.0V): 0.10sec/60° at no load
Stall Torque (4.8V): 119oz/in. (8.6kg.cm)
Stall Torque (6.0V): 144oz/in. (10.4kg.cm)
Operating Angle: 45 Deg. one side pulse traveling 400usec
360 Modifiable: Yes
Direction: Clockwise/Pulse Traveling 1500 to 1900usec
Idle Current Drain (4.8V): 3mA at stop
Idle Current Drain (6.0V): 3mA at stop
Current Drain (4.8V): 200mA/idle and 2.0 amps at lock/stall
Current Drain (6.0V): 240mA/idle and 3.0 amps at lock/stall
Dead Band Width: 2usec
Motor Type: Coreless Carbon Brush
Potentiometer Drive: 6 SliderIndirect Drive
Bearing Type: Dual Ball Bearing MR106
Gear Type: Karbonite Geas
Connector Wire Length: 7" (178mm)
Dimensions: 1.57" x 0.78"x 1.45" (40 x 20 x 37mm)
Weight: 1.87oz (53g)


For 4WD I prefer more torque to get all the wheels around in my SCTE, granted it's a heavier truck. Also if your receiver can handle 7.4V, I know the Futaba FASST can, it means that you can run the servo directly from your 2S lipo.

HS-7945TH Multipurpose Ultra Premium High Voltage Digital Servo

http://www.hitecrcd.com/photo.php?pi=887&size=four


Motor Type:7.4v
Wind Coreless
Bearing Type Ball Bearing
Speed (6.0V/7.4V):0.12 / 0.10 second @ 60°
Torque oz./in. (6.0V/7.4V):250 / 319
Size in Inches:1.57 x 0.79 x 1.50
Weight oz.:2.40

Thanks for the input! That 7945TH looks great, but it's way more money than what I'm looking to spend. Under $50, I've been choosing between the 7975HB and the 5645MG. The 7975HB's specs look better, but my concern is durability. You haven't had any issues in land vehicles with the 7975HB being non-metal? I figure going digital is a worthy step up from the 645MG? I'm looking to have fun getting around a track, but don't expect to get into hardcore competition.