servo torque for a trex?
 

hello,
i want to know how much torque is enough for a trex? i dont have a trex right now, only a blade cp, however, i plan on getting a 7c and my lhs will make me a deal with micro servos and micro reciever. so how much torque is need for the ccpm version? what about speed? i'm no 3d flyer yet but i can do loops with my blade cp and believe that 3d is not a long way off...
any help appreciated.
thx

RE: servo torque for a trex?
 

You would not be wrong to go with 4x HS65 or 4x HS56
If your budget is a bit bigger, only get 3x, and put a digital Futaba 9650 on the tail. Of course, the only gyro you are considering id the Futaba GY401, right?
Vince

RE: servo torque for a trex?
 

and ABSOLUTLEY plan on a pcm rx, it will solve a great many issues for the extra $30 or $40 dollars...

RE: servo torque for a trex?
 

yes, when i get a trex, i'll get a 401 with digital servo. however, the deal my lhs made me was with these micro servos,
S3103
SPECS: Speed: .11 sec/60 deg @ 4.8V - .09 sec/60 deg @ 6V
Torque: 17.0 oz-in @ 4.8V - 21 oz-in @ 6V
1.2 kg-cm @ 4.8V - 1.5 kg-cm @ 6V
Length: 0.86" (21.8mm)
Width: 0.43" (11mm)
Height: 0.78" (19.8mm)
Weight: 9.5g (.3oz)
will these be enough?!

RE: servo torque for a trex?
 

Those servos will work fine if they fit. Make sure that the servos fit in the frame. Most people are using the hs65. I have HS56 and see no problems. The standard nylon gears are easily damaged in the helis. I have a friend that had HS55 servos. It worked but a few hard landings stripped the servos.

RE: servo torque for a trex?
 

I note that Align and Horizon are recommending the Spektrum DX6 and its micro servos for the current TRex 450 lines. I love the DX6 but haven't tried the servos yet. Any thoughts?

RE: servo torque for a trex?
 

i think i'll go with a HS65 metal gear version with an SE, so i won't strip servo gears everytime i crash while learning 3D.

RE: servo torque for a trex?
 

Anyone who recommends the S75 servos for a T-Rex is on crack. They are just plain trying to take you for your money.
These servos are junk. The have hideous centering.

Have I made myself clear?

I really don't like bashing products or vendors like this, but I had read a LOT about how bad these servos are. And then I got to see them in real life. Nothing I had read prepared me for how horrible the actually were.

Spread spectrum is great. But those servos are junk.

RE: servo torque for a trex?
 

i never thought that spectrum comes with the S75, those are the stock servos on a blade cp. even a new one will have like 1/8 an inch on slop. like said, hideous centering. before i read about the good servos, i thought that all average micro servos will have that amount of slop, but i guess i was wrong... definitely go with anything better than HS56, perferably a HS65.

RE: servo torque for a trex?
 

OK, I found out. The Spektrum servos are in fact junk. Out of four new ones, one almost caused a crash when it decided to quit centering and wiggled from about 1/4 left aileron to 1/4 right aileron just at liftoff. Fortunately I caught it, and the LHS gave me no grief when I traded the defective one in on a HiTec HS65. Now I'm running 4 HS65s and will never look back. The remaining S75s will be temp spares for the BCX, maybe.
Hopefully they will ship something better with the DX7.

RE: servo torque for a trex?
 

one more question, will the metal gears in teh HS 65MG increase interference?

RE: servo torque for a trex?
 

Dunno-some would say so I guess. But I'm using a DX6 system which seems to be immune to the ordinary glitches that used to plague us on 72-75 MHz. Plus the transmitter antenna is only about 4 inches long--a real feature for us living-room hoverers.
But here's the real reason I'm using HS65HBs instead of the metal geared ones--the difference in price is such that I could strip out and replace three sets of Karbonite gears for the same money. Or buy an extra servo--3 65MGs = 4 65HBs.
Those servos are so strong that for a little bitty heli like a TRex or my "Heli-Rex TMax 420" something else will probably break or bend before a HS65HB will strip. If I put a 65 MG on the tail I could probably fly the heli under water.

RE: servo torque for a trex?
 

No MG does not cause interference. What you want is the HS-65MG x 3 and I went for a JR DS3400G mini gyro servo x 1 and either a futaba 401 or JR 500t gyro.

RE: servo torque for a trex?
 

yes, i will go with 3 HS 65 MG's, so the DS3400G is better than the S9650 and the JR 500T is better than the 401? do i need that much holding power on a small heli? i will be doing 3d though, already doing stationary rolls with my blade cp.

RE: servo torque for a trex?
 

The 3400G is the best gyro servo right now IMHO. the 401 and 500T are very comparable. The 500T is a little better but needs a little more tuning to setup perfectly (but thats part of the fun). The 401 is still excellent and is very easy to setup

RE: servo torque for a trex?
 

I'm using S3103 servos on the round, and on the tail. I've had no problem with these servos. They're good and strong. The only beef I have is that They aren't digital so I can't take advantage of my GY401's digital capabilities on my tail. I'm actually leaning toward the 577 from Helidirect for my tail. I got 4 S3103's with my 6EXH radio.

Also, I tried using an e-flite servo on my tail (per the LHS's recommendation). I was doubtful, and my doubts were not unfounded. The tail was completely out of my control. So I moved it to pitch (had one S3103 w/ stripped gears). What happens there is that once you get to a certain angle, the force on the blades pull the linkages and tow the servo along with, causing maximum pitch only recoverable by dropping the head speed. (That was spooky, and straight-up pissed me right off)

Those servos should not be marketed for anything other than sub-micro 'toys'.