Servo bench testing

[Enterprise]

Because of the impending snow storm Vulcan, we got together and did some testing on the new servo and a Savox 2231.

TGY-3509MG got 420 oz-in
Savox 2231 got 460 oz-in

Now with the two big Savox the whole rig is moving so they probably put out more than that. The mouse trap still needs improvement, but they are very powerful. So far the Turnigy seems impressive for the money. It tested in the same ballpark as the BLS-157 and the Savox 2270. Long term, who knows.

 

[skibum44]

Finally did some testing with my MKS HV777s that are going in my 91" extra. They peaked at 478oz-in and 5.93Amps. You could see numbers in lbs in the video... Couldn't figure how to change my Rapala scale to oz. I think I need to replace my cheap RX packs... They seems to be staging pretty bad, but so far pretty impressed with the servo. So far so good for $107 ea.

[video=youtube_share;cuBkhHAEywY]http://youtu.be/cuBkhHAEywY[/video]

 

[Enterprise]

Cool, another data point. I like how you did you amp meter. When I used the H9 servo meter, the torque fell off due to a lot of line loss inside the thing. Next time I will hook a regular amp meter inline with one of my powersafes as they are already setup on the bigger connectors.

 

[gyro]

Isn't that a lot of amps?

 

[Enterprise]

Yes, 7955s draw about 3 amps. Realize that is at full stall current. You would only see that spike for a few millaseconds in flight. The servos get hot doing this testing. This is where brushless servos shine.

 

[skibum44]

478oz-in requires a decent amount of power... I was actually expecting more amps then I got.
Not a worry for me as Enterprise said it is full stall current that the 50cc they are going in will not get close to. Also the the 9110 power safe RX is good to 30A continuous and 50A peak, so I would need 6 fully stalled servos to even get close to max continuous current rating... I'm only running 5. Also, voltage will sag more on the RX batteries with that load so 5.93A per servo isn't likely running 5.

 

[Enterprise]

That is why for the test rig we will use a BEC so that we don't get the voltage sag and get consistent results.

 

[ghoffman]

I revised my servo tester. Now I think I will get a better current meter as well.

 

[skibum44]

Here is one of he elevators for my 91" extra to show the speed.
[video=youtube_share;5B3llwr0z9w]http://youtu.be/5B3llwr0z9w[/video]

 

[ghoffman]

That is why for the test rig we will use a BEC so that we don't get the voltage sag and get consistent results.

I plan on using a power supply from Tom Lianza.