Kick A** Servo for IMAC

[scaleguy]

Well guys you might think this should be in the electronics forum but I just had to post this here since most of us who are or will be flying 28% and larger aerobatic aircraft are always looking for brute force servos for them.

Came accross this add in the December 04 isue of RCM. Well you might say yeah big deal 220oz, Hitec can match that... difference is in the size and the weight of the servo. I happened to be in HobbyHobby and he has a wall of these 8611s. Apperently the car jockeys have been using this for a while for stearing!

I was also looking at the Hitec 5745 but man it's a baheemoth next to the 8611 puts out less or about the same torque.

Hmm maybe for my 68" Yak rudder and definately for just about everything on my 87" Yak.

[AJCoholic]

Jim, the jet guys have been using the 8611 for a while too. They are a brute no doubt.

[Cecil Marshall]

Jim:
How much is HH selling them for?

[scaleguy]

Cecil,

Sorry meant to include that in original post.... $159.99 each! :yikes:

[AJCoholic]

$149.99 at Great Hobbies

[scaleguy]

$149.99 at Great HobbiesAndrew,
Thanx for pointing this out. Tom at HobbyHobby will match any published price.

I would assume you got price on-line and I expect he would match that too. :D :D

[AJCoholic]

its the catalogue and on line price and remember no PST, and free shipping over $100

[Bob Hudson]

The JR 8611 is truely a great servo. ( "kick ass" )
http://www.horizonhobby.com/Shop/ByCategory/Product/Default.aspx?ProdID=JRPS8611

Another alternative would be the new Futaba S9152
http://www.futaba-rc.com/servos/futm0211.html
http://www.gpmd.com/cgi-bin/wgpinf100p?&I=FUTM0212

Both of these servos are bigger than you need ( in my opinion) for anything under 80".

The JR 8411 would suffice. Even the JR 4721 analogue would do. ( if you're on a budget.) Hell, they put out 120 inch/ounces !! We were flying 35% Carden Extras and CAP's with 1 on those on ailerons or elevators just a few ( 2 or 3 ) years ago before technology passed them by.


Just a caution about the "kick ass" models ( mentioned above ),

They have a slightly bigger case size ( wider and longer) and mounting screw footprint that the "standard sized" servos. They "may not" fit your servo bays if you are looking for a "drop in replacement" with more horse power.

http://www.rcflier.com/pics/smiley-flag.gif

[Rob]

Bob i have had 3 4721 go bad on me and i dont think i have them in too big of a plane. ( 80" hanger 9 Cap 232 15lbs) I can see one going bad but three all doinf the same thing ? i have replaced them with a diffrent servo and have had noproblems so far.

[Bob Hudson]

Bob i have had 3 4721 go bad on me and i dont think i have them in too big of a plane. ( 80" hanger 9 Cap 232 15lbs) I can see one going bad but three all doinf the same thing ? i have replaced them with a diffrent servo and have had noproblems so far.

Rob,

I am interested to hear of your problems.

Specifically what application did you have these servos on? ( aileron, or elevator, or rudder? )

thanks

[ronm]

I would be interested to hear about 4721 problems too, as I have 5 of them in my 1/3 scale IMAC plane!! :shock:

[Rob]

Two of them were on my aileron and the other was on my elevator. it had 4721s on everything. i still have one on my Rudder and two on my elevator. (i am going to replace them all when i get some money.) I bought the plane used and the guy i bought it from said the servos only had 20 flights or so and i know i didn't event get 10 before the first one started to jitter. Not a normal jitter more like a flop. It was in my ailerons then the other on the other side started to go and now the one an my elevator. all seem to be doing the same thing. When around the center they start to flop alot not just a little. My aileron would move 1/8 up then go to 1/8 down so a total of 1/4in of movement. NOT NICE TO FIND WHILE FLYING. If you would like you can call me and i will explain more if you would like pm if you want.

[scaleguy]

Bob,

Thanx for the input. Yeah I thought it would be overkill for my 68" Yak but I think the servo of choice for my 87" Yak!

Ron how did you find the 4721? Are they a good value?

[ronm]

I guess I got about 50-60 flights on them, first on my 80" Cap, then on my 96" Laser. They seem to be working perfectly. One airleron servo hums a bit, but I think it just doesn't know the words??!! :wink:

I wonder what caused Rob's to fail like that?

Rob, did you ever send them to be checked out to see what went wrong?
At about $120/ea it would be worth it.

[AJCoholic]

Hey, sometimes even expensive servos fail.... I had numerous failures over the years, including 3 of 5 brand new coreless high torque contest Airtronics servos, and two JR 4000 super servos.

Like the guys who have failures with any other brands (hitec for instance) dont let it worry you too much if you are not having any troubles.

Even the 8411 has reported failures...

I would like to try some of those 8611's in a jet sometime to compare to the Hitec HS 5945's I run currently.

[ronm]

Andrew, three good quality servos failing on the same plane at around the same time is just a little bit suspicious! :?

[AJCoholic]

Yes Ron, but they have no direct relationship (you hope! Maybe they did come from the same production batch) to yours....

My point (and it is only my opinion) that if you see a guy have such a failure, it is not tomean that all of a sudden all of these particular model servo are suspect, get my point?

I coulndt believe that I paid $130 a pop back in 1995 for these top of the line Airtronics servos, and 3 of the 5 failed on me within a few hours use. But sometimes S**T happens eh?

[Rob]

I havent sent them back yet i will be boxing them up anf shipping them off. I will ley you know what was wrong with them when i get them back. I wasnt trying to scare andyone but i was just letting you know about my experence with the 4721S thats all.

[AJCoholic]

Just to be clear, all I was trying to do was suggest that just because Rob has had a problem with these servos that Ron shouldnt be worried crazy about his, thats all... nothing more :)

[scaleguy]

Andrew,

Yes I think everyone will understand the intention of your post.

It is the same issue with just about anything manufactured today wether it be a servo, TV, car, fridge whatever. Sometimes you run into Murphy full force. I think no one brand is worse then the other.

I will probably stay with the Hitecs I bought, 5645s, for my 68" Yak but might give the JRs, either 8411 or 8611 or combo of both on my 87" Yak. Heck I might even try some coreless Airtronics servos. :wink: :wink: But never ever Futaba. I just don't like having to cut off the tab on the connector! :wink: :wink: :lol: :lol:

My only regret now is that I wish I had a got the 5625s, there response time is faster. :( :( Still might go to something a little stronger for the rudder though... man is she big!

[ronm]

Don't get me wrong Andrew, I'm "extremely curious", not "worried crazy" :wink:

[PurgatorY]

I havent sent them back yet i will be boxing them up anf shipping them off. I will ley you know what was wrong with them when i get them back. I wasnt trying to scare andyone but i was just letting you know about my experence with the 4721S thats all.

4131's and 4721's were the frontline JR pattern servos for years, its what I was using when flying pattern on JR never once had a problem with any of them....great servos in their day.

I also had JR 4000's/7000's, the precursors to digitals, also great servos except they ate too much battery. In fact I still have them and use them on occasion :)

As for failing 3 servos on the same plane, that seem strange to me....perhaps the wrong application for the servos?

I have a couple of friends who have 8411's, I am not impressed with these at all....in a matter of a few hundred flights the pots are toast and they start to flutter around neutral when you turn on the radio, it goes away as soon as air load is on the surfaces but a high end servo should last longer than that.

[Tiger]

I have always held high praise for the 4721's. They are truly a great servo although they are a little dated now.

I have had two go south on me, but it was caused by excessive mid throttle vibration in the tail surfaces. The pots get worn very fast on any servo if the vibration is bad enough. Maybe this was your cause to have three go bad so fast? The symptoms you described sound a lot like mine.

Cheers!
Dale

[AJCoholic]

As for failing 3 servos on the same plane, that seem strange to me....perhaps the wrong application for the servos?


Hey Chad, sometimes things just DO happen... in my case when I had three of five fail they were very, very lightly used (in a 60 size heli - they were their contest heli servos) and I basically just flew around. Later two failed in a plane, a 1/4 scale giles one on an aileron and one on an elevator. The servos in my case "worked" - ok they moved - but as soon as you applied the lightest load they stalled. I just chocked it up to a bad run or something.

But when you consider how rare that is, for even two servos of the same type failing in a single airframe together, considering how many people are flying in just North America alone... its not common at all.

[PurgatorY]

As for failing 3 servos on the same plane, that seem strange to me....perhaps the wrong application for the servos?


Hey Chad, sometimes things just DO happen... in my case when I had three of five fail they were very, very lightly used (in a 60 size heli - they were their contest heli servos) and I basically just flew around. Later two failed in a plane, a 1/4 scale giles one on an aileron and one on an elevator. The servos in my case "worked" - ok they moved - but as soon as you applied the lightest load they stalled. I just chocked it up to a bad run or something.

But when you consider how rare that is, for even two servos of the same type failing in a single airframe together, considering how many people are flying in just North America alone... its not common at all.

Thats what you get for buying Airtonics LOL :twisted:


The strangest thing I ever had happen was two aileron extensions failing at the same time, on the same day.......at the Worlds right before official practise like 5 minutes before my time slot.....no way thats a coincidence...damn gremlins thats what does that :) Had to switch time slots with my teammate, dismantle my airplane drop out both servos and replace the extensions in 15 minutes. I was so nervous about the problems I ended up using my backup model for the practise.....what happens BOOM my nice backup YS 140DZ ate itself to peices LOL Good thing I brought 3 motors :-)

[scaleguy]

Hey Chad,

Two things....

1) So what servos do you use now?

2) How did you sneeak that big avitar in? Did Jason open up the size restrictions for avitars and didn't tell anyone? Or are you using a link in your avitar section.. do tell!

[PurgatorY]

The Hitec HS-5559TG look interesting especially when powered with 6V

http://www.hitecrcd.com/product_fs.htm

Dennis

[Gary Maker]

The Hitec HS-5559TG look interesting especially when powered with 6V

Hey Dennis, I think your dyslexia just kicked in. I believe that should be HS-5955TG LOL. Sorry, couldn't resist that one :wink:

[PurgatorY]

Hey Chad,

Two things....

1) So what servos do you use now?

2) How did you sneeak that big avitar in? Did Jason open up the size restrictions for avitars and didn't tell anyone? Or are you using a link in your avitar section.. do tell!

Hi Jim

1) I have been using the following Futaba servos without a single failure for the past few years..... 9252, 9151, 9402, 9204, 9602, 9650, 3150, 9150, 9154, 3101, 3102, 3107. The applications range from pattern, 3D fun fly (40 - 140 size), 3.5 cc pylon to park flyers.

2) If you link to a picture hosted on another site (ie: your personal webspace) it can be any size that you want :) At least until Jason finds out and kills that possibility :)

[PurgatorY]

The Hitec HS-5559TG look interesting especially when powered with 6V

Hey Dennis, I think your dyslexia just kicked in. I believe that should be HS-5955TG LOL. Sorry, couldn't resist that one :wink:

Thats ok I was drooling over the new Revolution 52cc engine I had in my hands when I was typing it.

Dennis