Enterprise7

Which would work better for 3D-4D aerobatics on an SD Models 30% Extra 260? (just on the elevator and ailerons)
Elevator servo(s) torque requirement - 100 oz/in
Aileron servo(s) torque requirement - 120 oz/in

The choices and their specs:

Hitec 5625MG $45 Hitec 5645MG $45
torque: 131 ounces torque: 168 ounces
speed: 0.14 seconds speed: 0.18 seconds

Both have 3 pole motors and way 2.11 ounces.

mtwister

I think your servo choices are the bare minimum you should run. The 5645 is a good servo, but slow, so not so great for 3D. the 5625 is fast, but low torque, not good for a 30%. I think you'd be a much happier person by investing just a few more dollars and moving up to the 5945's. Then you'll get serious speed and power. Oh, and btw, the ailerons are very very important on a 30% to have sufficient servo's. Those are some big surfaces man.

greyhound man

My Feedback: (5)

Exactly what MTWISTER said, I have a 30% SD yak and am running 5945's on the ailerons and I have been thinking of upgrading those to stronger servos as they are ok, but lacking in authority at high speed. personally I think you will be disappointed in anything less than a 5945 or equivalent.

rcairflr

My Feedback: (44)

My vote would be for none of the above. Go with all HS-5955's, for the extra up-front investment you will have servos that will last a long time, have little to no gear wear and will move into any airplane you buy as you move into 33-35% airplanes.

camss69

My Feedback: (46)

Agreed

gooseF22

AGREEE 100%
Im going to be a little stronger with you. My suky had 5645's on it, and we canned em for 5955's. the difference was simply unbelieveable. the thing is a monster.. It has all 5955's on it. I got rid of the dual rudder servos and run one pull pull with the 5955 too. Plenty of power for the 33% size. When you go up to the 35%, then the new 8711 becomes the heat before you have to double up 5955's. I know alot of guys that run one 5955 per surface on 35% and love em. I know alot of guys that run 8611s in the same.

One of the best flying yaks I have seen in the 30% is a buddy's aero works yak with all 8611's. It is fast, precise, and a wonderful flying airplane. He sold all his other servos.

the only thing I use a 56 series servo for nowadays is a throttle or choke in a GS. I am also not a fan of the 6 series analogs either.

Mty vote 5955's or JR 86/67 series for GS planes. On midsize planes, Im less picky, but I have been liking JR digitals, or the new sport 821 digitals that come with almost every JR radio. On the hitec side, I would stick with the 59 series.

AHPowelson

My Feedback: (37)

It's always easier to spend someone else's money.. If you're on a tight budget, the 5645's are fine. They are slow and don't center that well, but will not be a potential point of failure. If your budget allows, 5945's are the way to go. 5955's are even better, but simply overkill unless you're really trying to be serious about things. 5625's would ok on the elevators, but not enough on the ailerons, IMO. I run 5945/55's on everything; however, I do have an old 87" EF Yak that I use strictly has a beater/knock around plane with 5645's on the ailerons and elevator. It's had a few years and a couple hundred HARD flights worth of abuse and the ol' 5645's are still running strong. It all depends on what your budget allows.

Hawk21

My Feedback: (7)

well the 5645 is slow but can do the job right, I did set up one
30% TOC (SD) yak with 5645 all around an is flying with out problems.
But if you can put a better servo, I would recomend the 5985 or 5955

flying skunks

My Feedback: (7)

5625's on Ail
5645's on Ele
5985 on rudder
currently using this set up on a 30% Dietrich 260 and works flawless.
Donnie

tkilwein

I have a AW 36% Katana with HS5955TG's all around. Had 5645's in elevator halfs, they do not center well and have slop.
The 5955's are they way to go IMO if you have the extra cash.