D954SW High Torque Steel Gear HRC36954 Servos

Its an RC servo, what is there to say about it except: holy crap that is expensive! Well, yes, it is. But it also has a LOT of torque, a very small deadband (which can be adjusted) and is fairly quiet. I am using several of these for animatronics and they work very well. Many other (cheaper) digital servos start to "sing" when you do a bunch of very small movements, but these are mercifully quiet. Other cheap, high torque servos, (looking at you "bilda") have an obnoxiously wide deadband which might be fine on an RC car, but is terrible for animatronics or robots in general. If you don't need the torque, precision, tight deadband, and don't care about the noise, then there are a lot more cost effective options out there. If you do need it all, this is a darn good servo to get.

They come packaged in a small plastic container with various plastic servo horns you might require. I bought 2 of these servos and did not experience any sort of high pitch whine I had heard may be possible from other forums. Compared to my 20KG Generic Red servos, these things are a total luxury. The Reds were shockingly loud while these are very quite. I was not sure if I wanted to spend the money on these servos but am 100% glad that I did. Side note: these servos rotate in the opposite direction from the cheapo servos I was used to. In order to switch them (if your application requires it) you either need to be able to do that with software you are using or purchase the HFP-30 servo programmer where it is simply a case of plugging the servo into the programmer and navigating to the rotation setting and choosing the opposite of what it is set from factory as.

Incredibly accurate and precise. These digital servos are incredible, but very expensive.

I have always liked Hitec Servos, and these D series are even better

Edited 6-14-22: I recently purchased the Pololu Maestro Servo Controller and let me tell you, that made a world of difference!! Working with servos just became more fun, and dead simple. Moral of the story: Don't use a 5 dollar Servo controller for a 100 dollar servo. This servo is very precise now. Just bought 4 more (2 steel, 2 titanium). Original Review before the Maestro Servo Controller: I bought one just for testing purposes in my robot arm project, and I am very happy and will buy again. Let me state that I am no expert, but will gladly pass my experience on to others. Programmability: It's kinda tricky using the DPC-11, but at $24 instead of $60+, and really only 1 or 2 time use per servo, I figured I could manage. I was able to fine tune it to smaller sweep pattern (80 degrees instead of the max 200 degrees that you can set) by adjusting the left and right endpoints in the DPC 11 software. The resolution increases as the pattern decreases, hence repeatability and accuracy are improved as the full sweep length decreases. And I do not have to reset my min and max positions in my Arduino, (but I can if I need to). It can all be done with the DPC 11. This is all win/win for me! I like being able to slow the servo speed down in the DPC 11, and soft start is not very noticeable to the naked eye but I have not tested with an amp meter yet. Real life accuracy testing: I mounted a laser and pointed it 10" from a bullseye mark. I do notice this is not 100% accurate. I have home position set as 300 in my Arduino with PCA9685 servo driver setup. Moving to 300 from the left does not end in the same position as moving to 300 from the right. This gets more accurate with increased resolution, but I don't know if there is a servo that is 100% accurate in this other than maybe Dynamixel, which I have never tried and does not fit in my robot arm and costs twice as much. There is a tiny bit of backlash, but much less than my cheap hobby servos, but more than my expensive HSR-M9832TH. This servo moves very smoothly. Super quiet too. I am amazed how quiet this is compared to my lower end servos. To me it moves very fast at 100% speed, I slowed it to 10% (the min) is still a bit fast for my needs for a robot arm. I just slow it even more in the Arduino sketch during precise movements. The spline fits in extremely tight on first use, I hope this remains when I repeatedly remove and add the aluminum servo couplings I am using. Plenty of torque, and from what I've read Hitec underrates their power while many other servos overrate their power so don't let the numbers fool you. This uses a bit more power than my HSR 9382TH, and steel gears definitely do weigh more, but from what I've read titanium gears only real advantage in a servo is the weight, you're not getting 100% titanium and strength is likely only marginally better, if at all. I would consider that when making a decision between the 2 types. With that in mind I'll probably use 2 titanium gear models of this, the D955TW, for the outermost extensions of my arm at the gripper and wrist to keep some weight off the elbow and shoulder. From what I've read, Hitec warranty is excellent and hassle free. I will find out soon on my M9382TH, but a 2 year hassle free warranty is worth the added cost, if this is in fact true. Comes with a lot of high quality plastic fittings which I'll honestly never use, but one has a removable steel ring around the spline fitting to prevent it from cracking. 2 screws, Phillips and hex, and these screws are larger than standard servos. In the end, at this price point, I think these are a good tradeoff between a cheap servo and higher end servos. Good warranty, honest specs, pretty accurate, quiet, adjustable. Only thing missing is zero backlash, and a feedback loop😁, which is easy enough hack once the warranty runs out.

This servo is working great in my TRX4 sport. It has held up to plenty of abuse. It is not the strongest out there but for the average crawler it is plenty.