Question? What's good in cheap servos these days?

[Xpress]

Bart you should've gone with the HS-1005SGT for all surfaces.

I'm betting you'd make a lot of people LOL with that decision. $100 airplane, $1800 in servos

 

[tailskid]

Using them on a H9 110" Beaver right now....no problems. 130oz. torque for $30!

https://www.promodeler.com/DS130DLHV

 

[Snoopy1]

Looks really good for $30. It evan has 6 top screws on a 30 dollar servo.

 

[Jetpainter]

I'm considering some Promodeler servos for my next airplane and read today that there can be an issue with them when using a Spektrum Powersafe receiver. Evidently from what I understand there can be power spikes from the servos, I guess trying to feed voltage back into the receiver. On a PowerSafe it won't let the voltage feed back into the batteries so it spikes the servos and can evidently get as high as 9 volts from a 2s LiPo setup. The newer Hitec servos like the 9380 do something similar and come with a P.A.D. Power Absorbing Device that plugs into the receiver to solve this.

Anyone know anything more about this? I'm going to contact John from Promodeler and see if a PAD would solve this for his servos as well.

 

[Snoopy1]

I have heard the same but not how it was resolved. But as you have explained a capacitor will take care of voltage spikes, just have to pick the correct size and type.

 

[Alky6]

I'm considering some Promodeler servos for my next airplane and read today that there can be an issue with them when using a Spektrum Powersafe receiver. Evidently from what I understand there can be power spikes from the servos, I guess trying to feed voltage back into the receiver. On a PowerSafe it won't let the voltage feed back into the batteries so it spikes the servos and can evidently get as high as 9 volts from a 2s LiPo setup. The newer Hitec servos like the 9380 do something similar and come with a P.A.D. Power Absorbing Device that plugs into the receiver to solve this.

Anyone know anything more about this? I'm going to contact John from Promodeler and see if a PAD would solve this for his servos as well.

I have seen 9+ volt spikes in my telemetry from the first gen 9 channel powersafe receivers that I have (using 2s lipos). It does seem realistic that a capacitor should solve that problem. I am curious to hear what John says.

 

[Jetpainter]

I have seen 9+ volt spikes in my telemetry from the first gen 9 channel powersafe receivers that I have (using 2s lipos). It does seem realistic that a capacitor should solve that problem. I am curious to hear what John says.

I emailed him and asked, I'll let you know what he says.

 

[Xpress]

The PAD would mitigate voltage spikes (as that's what our Brushless do) but they only come with the servos from the factory.

 

[Bartman]

mine are still in the box, haven't worked on the plane much since before Christmas when I was doing basic rehab stuff to it.

 

[Jetpainter]

The PAD would mitigate voltage spikes (as that's what our Brushless do) but they only come with the servos from the factory.

I've decided to use 7954's