Actually, this is further from my post on digital and analog servos but I am quite confused so here goes.

I am about to purchase a GP Reactor Bipe. The aileron require 4 mini hi-torq servos (Futaba S3102, 9650, Hitec 225MG, 81MG etc). Now I had bought 6 # 225MGs last year out of which one failed even before we finished putting together the airplane they were intended for. Suqsequently, I used the servo test feature on my 9CAP and ran them for nearly half an hour continuously.

Now my question is should I use these 225MGs on the Reactor Bipe or get the S3102s. Basically the question is Futaba or Hitec?

Ameyam

The 225 standard gear servo is one of my favorites and I do use them in copious quantitys for many 25 sized airplanes and on ailerons of of many sixty sized airplanes.

I avoid the metal gear not because of cost but because of better resolution and centering with the plastic gears. The HS 81 you mention is to light for the job, metal gears not withstanding.

John

John,

my mentor is suggesting to check if the Reactor Bipe can accept standard servos (was quite sure they dont) and if not whether the wing can be modified to take standard servos. May be you could enlighten me on this.

Personally, I would also like to put in 3010s everywhere on that airplane, if it allows me.

Irrespective, I have been torturing the remaining 5# 225MGs using the servo test feature on my 9CAP for the last 45 minutes without any problems. Also, I found that the cost of ordering the 4# 3102s is the same irrespective of whether I combine with the Reactor Bipe or not. Given these circumstances and if the wing does not accept standard servos, do you suggest to use the 225MGs anyway? And will they be suitable for the Bipe 61 size with a FS91 SII engine?

Ameyam

OK, I ran them till my TX sounded a warning (total 1.5 hrs) doesnt seen to be a problem. Any suggestions?

Ameyam

G'day

I have used a vast number of Hitec servos. In all that time, only one has ever failed. I have used a smaller number of Futaba and JR servos and none of them has ever failed. The one Hitec that did fail worked initially but once fitted to a plane no longer worked so I removed it and later used it for parts.

I think that your one dead HS 225 is like my deal HS 422. Occasionally in the world of electronics, you do get a failure but usually it is very early in the life of the component. If you have components that work for some time, they are probably going to keep working for a normal service life.

I have seen a few old servos (over 15 years old) become noisy in time as their potentiometer gets dirty but this is just normal wear.

I think you can happily use those Hitec servos and any others you may buy and also any other servos with a recognised brand name on them.

That said, from time to time - and it will usually be a long time - you may have the very occasional failure.

My apologies for not getting right back but had to do an EAA Young Eagles gig at the airport this morning.

I can only say what I would do given your circumstances and the answer would be just like the old Army expression: Smoke'em if Ya Got'em. Sure I would use your 225mg's and not be afraid to in the least but thats only if there are four aileron servos which I beleve you said.

I do not know anything about the reactor since none have shown up here, so can,t answer anything specific.

The servo-cisor feature of your radio is very cool. I use an old dedicated Ace servo driver with the exercise feature and I do use with all new servos before they are ever installed for burn in. I don,t get too carried away with it but run them all for about 15 minutes. Its my feeling that indeed this will catch a few and can say honestly that the catchs I have made this way seem to run around 1%. While I use almost all hitech these days and that rate seems quite close to the other major brands I have used.

John

Read through the Manual and found that the ailerons do accept standard size servos. I have 5x 3010 servos, So I will need 2 more. I will also need larger servo arms (didnt see that before though)

Ameyam

I've used quite a few of the 225MG's and I would say they would be just OK if used one per aileron (4) 60 bipe or (2) sport 40 conventional wing. For elevator or rudder on a 40 size, defiantly not! Bear in mind these have gear trains that seem to have zero tolerance for over travel, slightest flutter or minor bump of the control surfaces. That being said, I have two in the wings of a Tiger II that have about 300 hard flights and still tight, smooth and fast.

You don't need all the servos in an aircraft to be the same...or even the same brand...you can even mix digital and analog.....HOWEVER....you can not mix servos on the same control surface....ie 2 3010's and 2 225's on the ailerons....control surfaces like 4 aileron servos all 4 need to be the same brand and model servo

Read through the manual (again) and it accepts standard servos in the ailerons as well. So I will be putting 3010s all over. I am using 3200mAh LiFe battery so capacity will not be a problem. My concern has now shifted to the connectors. Will be soldering the servos on the top servos direct to the y-connector and likewise the bottom servos. I am worried (due to similar problems on my Reactor 46) regarding the male-female connector that connects the top and bottom wings to the extension coming from the RX. On my Reactor 46, the same connector would lead to glitching in either of the wings almost every week. Is there another way to address this connector problem?

Ameyam

For removal of the wings you will have to keep at least some servo plugs just as you would in a simple monoplane it would be normal to keep at least one servo plug for each aileron servo to facultate quick and easy wing removal.

With that airplane for wing removal it would require at a minimum of at least one plug per aileron servo in addition to the actual plug into the rx.
I routinely use soldering for servo harness or extension etc. to eliminate an excessive number of plugs. This is where folks get into trouble, stacking on numerous various extensions and Y's. Where extranious plugs are problamatical is when its just a connector that is never unplugged and buried in the airplane somewhere, these are most likely to corrode and cause problems at some point. A plug that is often unplugged for transport is less likely to cause problems at some point.

With that airplane if I were not going to use one channel per aileron servo (and most won,t) I would most likely use two two aileron servos per channel. In doing this I would use a simple short Y chord (you don't even have to solder a custom chord) into the Rx, right or left channel and the servos I would splice in and solder extentions of the perfect length to facultate easy wing assembly or disassembly.

John

John,

you know I could actually use one connector per servo into the RX. I have a 6008HS 8C RX and there are 8 servos. However, if I do that, I simply increase number of connectors and hence possibilities of failures so I wont do that.

This last flying season, I did the former with my Reactor 46. And almost every week one of the ailerons seemed to keep moving after the other had stopped. That was tracked down to a connector problem every time. Finally I gave up and soldered the entension wire direct to the servo wire. So far this has solved the problem.

So, what I will be doing is, taking a y-extension and soldering its ends direct to the servo wires without intermediate connectors. That way I will eliminate the bad connector issue. Thus I will be driving two servos off one channel. Wont I need a servo reverser for this? My mentor was saying it wont be required.

Also, the manual recommends using 1.5" aluminium servo horns for rudder and 1" for aileron. However, seeing that I will be using standard servos, they come with "1.5in nylon cross-shaped horns" and "1.25in nylon 6-spoked horns" by default. Will I need these aluminium horns then?

Ameyam

Your mentor is correct. When two aileron servos are connected either with a Y or hardwired together for one side of the aircraft such as a biplane then there is no need to reverse one servo as long as the mounting and pushrod orientation is the same in both the top and bottom wings.

On the high strength servo arms (metal) which are intended to minimise servo arm flexing it is my opinion that since you are not using very high torque servos to start with that I would be comfortable with the plastics. These are all choices on how you are going to fly the airplane and only you can really answer that.

John

Was concerned with the issue of wiring the servos. As I read it, you are suggesting putting two servos, say on the LHS wings on one channel and the two servos on the RHS wings on another channel. In that case reversing is not required. However, it is not possible to do that physically. [8D]

As I see it, each wing becomes one unit. So if I were to use one y-extension for each wing, I would connect the top LHS and RHS servos to one channel for the top wing and the bottom LHS and RHS servos to another channel for the bottom wing. Only then would I be able to store the wings seperately and then assemble on field. However, this would cause both servos to turn in the same direction. Since they are opposed to each other in terms of installation, when one servo in one wing raises the aileron, the other in the same wing lowers the other aileron. This satisfies the "aileron" function so my mentor is right about that. But it also means that I will not be able to use a flap function. Also, that way I still have some control if any one of the connectors fails (EEK! What am I saying)[X(]

Then again for this kind of airplane and its handling characteristics, I will not require a flap function, isint that correct? Just thinking aloud here

With respect to servo arms, I dont like to fly very fast so it is not likely that the nylon arms will twist over. Just wanted to know whether the length in those arms is sufficient as to what the manual recommends.

I am also thinking whether 75AX or FS91SII (have both of them). That would be a whole can of worms to open, but if I do decide on the 75AX, I will need the muffler extension adapter to allow the stock muffler to clear the fuse. The 75AX gave me some issues with keeping it running last year on a certain airplane. But I think it may have been a tank height issue and fuel type on that specific airplane (have kept it oiled and sealed and never used synthetic on it since we moved to synthetic-castor blend, Klotz-100, a bit later). They weigh almost the same and will turn the same prop and drink the same amount as well. What is your thinking on the same?

Ameyam

OK in regards to servo reversing. Even in the case of two servos on elevator when using split halves (the most common need for reversed servos) depending upon servo mount orientation/positioning and linkage orientation its not absolutely neccessary to use one reversed servo. Its quite possible to not use reversing just by the simple expediant having the output arms on the opposite sides when the servo is mounted in the rear fuselage. However linkages must be paralell and identical and that means one servo is mounted higher than the other on the fuse sides and this is why its not often done this way by ARF'ers.

Even on a simple monoplane with two servos the servo mounting and output arms must be approriate for the application. I think we are both on the same line of thought but not sure[8D]

On the engine choice I don,t know your airplane so won,t go there and often my choices for engine types usually does not go with the popular flow anyway.

Just a word on the muffer extension though. I dislike pitts type box mufflers enormously and will not use them, overwhelmingly my choice is almost always a stock type muffler when not using a pipe with the two strokes. This often results in a difficult fit in fat fuselage airplanes with the guys always thinking of extensions and so forth. There really is a much simpler way and that is a simple muffler tunnel. Very easy to do just involving whacking out a notch in the firewall wherever needed and just shape some sixteenth inch sheet into a concave shape and glue in with some thin ca to form a rudimentary tunnel. Easy to do on most airplanes.

John

We are on the same line of thought with regards to the servo setup

No pitts type mufflers for me as well. I got one for the 75AX intending to use on the problematic airplane with engine at 90deg but never used it. GP usually build a muffler tunnel into their ARFs. But in the Reactor Bipe they decided otherwise. It would be a good idea to try 135 deg installation but first I would have to test my 75 AX on another airplane for that.

The 91FS results in a much cleaner install with the muffler sticking out from below due to the in-cown extension I have already purchased. It also means that the cooling cutouts in the cowl can be oversized and on the underside so that there is the best cooling effect (India is a hot place in summer, you know). I think the engine decision will be decided primarily based on what is available at the time I start putting together the Bipe. That itself is atleast a season off from now and by then I will know how the first FS91SII performs in the Topstar (Flip-3D) so I am not too concerned for now. Am still undecided on the horn issue though, will decide at purchase time.

Anyway, thanks everyone for the help

Ameyam

As I noted in your other thread, I am using micro metal gear servos(in the ailerons) and now have over 40 flights on the plane. No issues whatsoever with the strength. I have been flying the plane hardmy favorite move is a blender into an inverted flat spin, then into a hover. I used a 9" extension on the aileron servos on the top wing, which feed thru the fiberglass wing stanchion. I then use a Y harness to connect both right top & bottom and left top and bottom servos inside the fuse. I use dual aileron mixing just as if there were one wing and the Y connects the top and bottom wing.

BTW, the plane flies very nice "free flight". Yesterday, my battery came loose during flight, and after a few minutes: whoops, there goes the battery out the battery hatch. Since I'm just using the BEC from the speed control, I had no control. Plane was fortunately upright, and landed power off at about a 30 degree angle. Tore the gear off, but didn't even brake the prop! Didn't tear up the fuse much at all; should be able to glue the gear plate right back in. Looking forward to many more flights with this plane!