Hitec 7940TH ok for a tail servo?

[A.Delaney]

I have a Logo 500 in the works. I want an HV setup for it. I was thinking about using the 7940TH for the tail and maybe the cyclics. I also thought about the 7945TH for the cyclics with the 7940TH on the tail. I wont be using a rx pack. I want to keep it clean and simple. I will be running a 6s 5000 pack to a CC Ice 100 esc. I didnt want to need an external BEC. No reciever. It will have the full size V-Bar and 2 satellites.

[prototype3a]

I would want something faster that could do 760us/560hz but as far as I know, the only HV servos that do are the new MKS and Torq servos. I'm hoping Hitec will step up and make a brushless HV tailservo.

[A.Delaney]

Im not sure how this works. Looking at the BLS251 that alot of people use for a tail servo. At 4.8 volts the Tq is 53oz-in and the speed is .06sec. The Hitec 7940TH at 7.4v makes 222oz of torque at .06 sec speed. I guess I dont understand why its not fast enough but the bls251 is.

[prototype3a]

The big difference is that the BLS251 is brushless so it is able to accelerate more quickly. Also, it runs on 760us/560hz so that gives it even more advantage. Your average digital tail servo runs on 1520us/333hz so 760/560 servos can get requested position updates almost twice as often.

The 7940TH would probably be ok but it wouldn't be GREAT.

I've found this little app to be very informative. I just wish they had more models in it.
http://www.spartan-rc.com/resources/servodb/servo.php

[myrseth]

The ht don't work as a tailservo, we tested but it's amazing for swash. On my team we fly hitecs on swash and futaba bls 251 on tail, great combo but ofc you need a regulator for the tail.

[A.Delaney]

Thanks for the link. I guess I still have some learning to do.

[A.Delaney]

Originally Posted by myrseth

The ht don't work as a tailservo, we tested but it's amazing for swash. On my team we fly hitecs on swash and futaba bls 251 on tail, great combo but ofc you need a regulator for the tail.

How about Hitec for the swash and a Outrage BL9188 for the tail?

[A.Delaney]

It says on the spartan chart the 7940TH is for heli tail. Im confused. Ok so the way I understand it is 760 is the ideal frame rate. The 7940TH has the 1520 frame rate. So its slower? I dont really know what frame rate means. Or how Hz is involved. Im such a noob.

[myrseth]

It's not slower pr say but it does not have the same signal resolution so it does not correct as often as a bls 251 which makes the futaba superior for the tail.

The hitec is amazingly strong combined with great speed which is perfect for the swash, ESP direct link systems.

I have not tested the outrage series servos so can't comment on those.

Quick updates on signals is very good for small and rapid adjustments on the tail while strength and throw speed is good for bigger throws which is on the swash that should help your understanding