servo choice :yes another thread :-) + BEC question

[ojnab]

Hi Guys. Im gathering up the parts for my 425 build, slowly as budgeting allows

Ive decided on Savox SC0352 (cyclic), as these have been heavily discounted at a local store
Speed (sec/60°): @4.8v 0.16, @6.0v 0.13
Torque (kg-cm/oz-in): @4.8v 6.2, @6.0v 6.5

For the tail servo, to save some $$ i though about using my spare RC Car steering servo
Kopropo PDS-2345ICS
Torque: 6.0V: 110.4 oz-in (7.95 kg-cm)
Speed: 6.0V: 0.08 sec/60°
Weight: 1.92 oz (54.5 g)

Would there be any issues using a car steering servo for the tail ??
The KoPro works just fine on a 5v BEC , even though its specced for 6v

Since the safer idea is to run a separate BEC, should I just get a 6v BEC to get the better speed from the servo's ?? rather than run them all on 5v (4.8v??)
Would a 5A BEC be enough ??
Should I, could I also use the BEC from the esc, or just disconnect it ??

Cheers
Steve

[volens31]

Steve

Cyclics - fine.

Saving money on tail - makes me worry. I've been down that route before and in the end it was unflyable. I don't know that servo make for the tail but if you're going to spend bucks then do it on the tail.

With regard to the BEC. I run my separate BEC at 5A just because I don't need the extra speed or torque. If you're not doing heavy 3D then 5A will be fine.

If you're using the separate bec then there no need to use the built in bec, bypass it by disconnecting the red wire from your throttle channel and just have the black and white wires going into the servo plug. (Don't snip it off as you may want it in the future. Just pull the pin back and isolate it using tape).

And finally, consider a DS650 or a DS620 for your tail, the extra £45 you spend will be well worth it.....

Cheers
Nick

[ojnab]

Hi Nick

The Ko-Propo servo's have a great reputation , & are anything but cheap .
Being good servos's , I thought it may be a good tail servo, since I had one thats not being used. It wasnt designed for heli's though.

I have a Futaba GY240 gyro I plan to use.

[Jerrymac]

I would agree with Nick, don't skimp on the tail. Using a decent quality gyro, and dedicated rudder servo will serve you well and keep the tail locked in.

As far as using a separate bec, it depends on what esc you are using. If it has a switching bec rated at least 5amps it should be fine, otherwise, I would recommend using a separate bec rated for at least 5A. If you use a separate bec with an optional setting of 5volts or 6 volts, make sure the rudder servo is rated for 6 volts if you use that setting. If it's not, install a voltage step-down between the gyro and servo.

Jerry