Pada590

I am a beginning 3D pilot. I am currently assembling a Katana V2 70. I found very cheap and powerful Towerpro MG995 11,8KG servo`s.
Would I feel the difference between this servo and for example the Futaba S3050 (72 oz-in)
Any recommendation on the difference between analog and digital servo`s ? Any of the control surfaces to give priority ?

AFSalmon

My Feedback: (3)

Never heard of those but it has been my experience you get what you pay for with regard to good servos. I've been bit by cheap import servos myself. But to answer your question, if you are a beginner 3d pilot, you have much to learn before truly taking advantage of digital servos. Yes there most definately is a difference in responsiveness and precision but as a beginner you could certainly save a litttle money by sticking with good analogs for now. Later you could upgrade to digitals in say the 67" Fusion and really put on a show. As a minimum though, the Kat 70 should use at least 70 oz servos. I like 90 -110 myself in these size birds.

Pada590

thanks for this advice. When you mentione torque do you refer to 4.8 Volt or 6.0 Volt and which voltage do you recommend to use ?

AFSalmon

My Feedback: (3)

Well the torque output obviously is affected by the rx voltage. When I specify torque I am referring to real torque during flight so if you use a 4.8V pack then you'll need stronger servos to be equivalent to weaker servos on 6V. I always use 6v packs as this is the easiest way to get more speed and power from your servos.

flyhi2005

i got kat 70

futaba 3004 all around + 6V -1200 amps!!!
engine - tower hobbies 75 [sm=punching.gif]

XJet

Yes, you really would feel the difference when using the Tower Pro MG995 servos -- they are rubbish.

I recently reviewed these servos and they are absolutely awful. Very poor damping, massive overshoot, a deadband that is far too tight for the motor/gearbox and a feedback pot that wears out in a few short hours of use.

They are indeed a *CHEAP* servo. I'll be posting a full review/comparison on my new website later this month.

If you're going to fly hard-out then you probably want servos that will offer you at least 90oz-in of torque. I've used the Futaba 3010 which are fast and strong -- but sloppy, too sloppy IMHO for good 3D. They're also nylon-geared which might not be a good idea if you're getting *really* radical.

The other alternatives include Hitec's 625 (or the digital 5625) or 645 (5645). However, latter ones are a bit slower and as far as I'm concerned you can't have servos that are *too* fast when flying 3D.

Metal gears are a very *good* idea for larger birds like the Kat70 if you plan to throw it around or do tail-touches.

Most important of all, run a 5-cell receiver pack. It'll make whatever servos you use faster and torquier -- for very little extra cost or weight.

AFSalmon

My Feedback: (3)

I've also found that the new Hitec karbonite gear digital servos are very good choices for 70 and below size planes. The advantage is the karbonite gears have ZERO slop and do not wear like the metal ones will over time.