Hd Servo Recommendations


Hey guys.

I'm looking for recommendations for a heavy duty servo, the same size and power requirements as the EZ-Robot HD ones, but at least twice as strong in regards to torque and holding positions, and that will also play nice with the EZ-B.

I know that most, if not all servos will work with the EZ-B, and I have looked online to see what's available, but I'm hoping someone can recommend a strong reasonably priced servo you might be using and would suggest.



Hey man,

We bought some heavy duty servos for what we were doing, but they still only lift a few pounds I think. You might still want to do some research on them, but they sound like what you might want.

They're called Hi-Tec (HS-5685MH) servos; here are two websites that talk about it: https://www.servocity.com/html/hs-5685mh_servo.html#.VVvYoPlViko

We also bought some metal hubs for it instead of the plastic ones they have. Let me know if you want the link for that.



Thanks for your response and recommendation. The Hi-Tec HS-5685MH you linked to is rated for 12.9kg-cm stall torque at 7.4v, where as the EZ-Robot HD servo is rated at 15.0kg-cm ST which is not strong enough for my needs, so it's not quite what I'm looking for but thanks all the same. I want something around the 30 to 40kg-cm range (or more) at the same voltage.


@Steve G... Unfortunately, I think it will be hard to find a standard sized servo that can output that much torque... Even the giant scale servos in inMoov only produce about 25kg-cm...


Check out Pololu.com, I think I remember seeing a couple of servos that can lift
up 1600oz/in, and run at 12vdc. A bit overkill maybe but really cool !


Hi Steve,

Not inexpensive at all but the HS-7950TH will give you a Stall Torque at 7.4V of 486oz/in (35kg.cm). It's very pricey at about 150 USD at Servo City. I have a few of these in my B9 arm and they work nice and are tough little standard size servos. However like all Digital servos they do have a whine when holding load.

"Ultra Torque" HS-7950TH

User-inserted image

If you really want to add some monster torque install them into a RobotZone Gearbox. Expect to pay about 220 USD or less at ServoCity for this setup depending on what you order. You can also put a smaller and less expensive servo in these gearboxes and drop the price. The gearbox alone will cost about 70 USD:

RobotZone Gearbox & Servo

User-inserted image
User-inserted image
User-inserted image



I'm beginning to think your right. I've had a good long net search without much luck, and the couple I did find were crazy expensive. The only one I did find so far that comes close to what I'm looking for is this. It's slightly bigger (at 6.5x3x5.7cm) but I may be able to work with it and look's strong enough, and not a bad price either...

User-inserted image

Btw, I'm pleased that David C and yourself enjoyed your trip to the inner sanctum. Sounded like you had a great day at the office. I'm supper jealous, but maybe I'll get there, one day. Tongue


Thanks for the link. I saw the servos you were talking about, but I'm looking for something to run on a 7.2 / 7.4v set up. I did see this however this which doesn't look to bad, and the price is right.

User-inserted image


Thanks for the recommendations Dave. The HS-7950TH is a bit on the pricy side as you say (but I've seen worse though), but does look a lot more like what I'm looking for so it's something I just may conceder. The gear boxes do look like a great option, and something I may consider investing in for a future project, but for what I'm looking for now, I have space restraints so unfortunately these I wouldn't be able to use one of these.

Thanks guys. Smile


Wow, nice find @Dave... but the price!



Yeah I gotta admit, that's the one thing holding me back from ordering one. Price.


@Steve.... Can you not use a cheap geared DC motor and potentiometer in your joint that you are controlling? However, I realize servos are more of an elegant solution to moving joints....