HS 7954
 

Hi All:
I bough 8 HS7954 servos and they present a weird behavior: the travel speed is not constant. They slow down as they get close to the center. More bizarre, if you give a tiny touch to the opposite direction (eg. full right and then center with a bit of left and back to center) the servo does not slow down!

I have compared these 7954 with 7955 side by side using the same RX channel and the difference can be seen, both on the change of speed as it nears the center and the full travel. Both servos are programmed identical. I was told that the 7954 and 7955 are identical except for the steel gears. I have videos that prove this. I can't believe that 8 servos are just bad. Is it a characteristic ?
I hope to find the truth behind all this.
Thanks
JC

RE: HS 7954
 

A quick update about all this issue:
I have been told both by phone and in writing that the HS7954 and HS7955 are identical except for the steel gears. Now I am told that the 7954 are different and the "problem" I experienced is normal for this servo... Well not a problem anymore, just the servo is like that!


There are several things that I want to bring up about all this:

1. Advertising should be done in a more clear way so there's no surprise.
2. Why Hi Tech makes such a degrading performance characteristic into a servo ?
3. How come Hi Tech didn't know about this before ? If this is a characteristic, how is that it is not published/not known by their own people ?

Just a thought.

JC

RE: HS 7954
 

The difference is the gear material (steel vs. titanium) and the high voltage chip used to make it 7.4 volt compatible. There was nothing wrong with your servos, they perform as they are supposed to but when comparing it as you did with your video to a 7955, the return at neutral with the 7954 will slow slightly when compared to the 7955 because of the difference in using a high voltage chip in that servo.