gregman50

I'm getting ready to put together the 35% Extra 260, the manual calls for two servos on the rudder @ 180oz. torque, my question here is would one 7955 (333oz.) be enough for the rudder or should I go with a 8711, the only reason I don't like the 8711 reports say after about 25-30 flights the gears get slop in them and they are not programable either. I'm not going to 3D the plane, just sport fly with it. All the rest of the surfaces will have 7955's for the exception of the throttle. Thanks in advance.

sweetpea01

My Feedback: (10)

I have no experience with the Hitec servos but I know alot of folks running 1 8711 on the Rudder.

I run 2 8611a's on the rudder in a push/pull configuration in the tail though.

Ferocious Frankie

My Feedback: (7)

The general consensus is that 1 8711 will do the work of two 5955s. There is a report on Troy Built Models from the author saying that when he did knife edge loops with 2 5955s they were strong. After he switched to a 8711 he noticed no difference in rudder authority in the knife edge loop.

Here's the quote from TBM:

"JR-8711 vs Hitec HS-5955 in actual use. This test started with using one HS-5955 servo in my 35% Extra 260. I had just enough rudder power to perform a knife edge loop. However I noticed that the rudder lost power later on in the flight. Apparently this was due to the servo heating up and losing power. I added a second HS-5955 servo and the difference was tremendous. Rudder authority was like a foamy plane. I then switched to one JR-8711, and there was no detectable change to the rudder authority compared to the two Hitec HS-5955 servos. This confirms that the above test results of 152 oz-in vs 280 oz in is realistic and usable."

smarks

Try it with one 7955, if not enough, add another one later. I bet one will work though. I wouldn't use an 8711 because of the gear slop issue. If you can wait, Hitec will have a 400 oz. servo coming out hopefully in March/April. HS7950TG.

gregman50

Thanks Smarks, I have heard about the issue with the 8711 and did'nt really want to go with it. I will try one 7955, if it does'nt seem to be enough I will add another. I think that the type of flying I do it will be sufficent.

Smacka

This is the servo I am waiting for (HS7950TG) and will install in my AW 85cc Yak 54. I am in the planning stages of the build now, and I think these Hitecs will be the cats arse! I will definitely be going through a learning curve with the programming and the new programmer. It'll be a hoot! I am looking forward to the challenge.

Have fun!

gregman50

Yea, I may just wait on the 7950 for the rudder, it will be late March or April before I get to fly again, due to work here, maybe the 7950 will be on the market by then.
I need to buy me a programmer, the last time I programmed my servos I borrowed a friends so I think that I am using Hitec servos all the way I will just go ahead and invest in it.

jkhorvath

My Feedback: (1)

I originally built my Aeroworks 35% Extra 260 with a single Hitec 5955 in the rudder and found that it would not hold a knifedge. I added another Hitec 5955 and felt a world of difference in the rudder. Note that this is running 4 cell NiMh packs at 4.8 volts. If you are building this aircraft with 4 cell Nickel chemistry power, then use two Hitec 5955's or 7955's for the rudder

cap10b

All,
Im flying an Airtronics 94780 423in/oz metal heat sink case, metal gear digital true standard case servo in a 50 cc composite plane. So far so good. If
this continues I plan to run two in a 2.6 Comp Arf 260. Lighter stronger faster than 8611a and 8711 (Of which I own a bunch of) so If all works out
I may sell some planes with servos and restock with ATX 94780.

jds

gregman50

I will be using Li-Ions with regulators which will give me the 6.0 volt to the servos. That will be 333oz. for a single 7955.