Servo Specifications for 40 size profiles
 

I just wanted to tap the Bro's knowledge on servos.

I'm trying to find the best/most cost effective servos to use in my Sledge. After having so much trouble with Hitec servos lately, I've decided to start using JR servos but I was just wondering how many ounces of torque is needed for good performance in a 40 size bird.

I'm extremely weight sensitive and like to build as light as possible.

RE: Servo Specifications for 40 size profiles
 

Standards are fine for any 40 size birds. I love all my Hitec and Futaba Servos, with a couple of exeptions. If you look at the specs on a Futaba 3004, it's over 70oz on 6v, way more than you'll need. I REALLY like the new Hitec standard size digitals on my Sledge. They have great holding power. But knowing that there are Bros flying 40 size planes with hs85's and hs225's and hs 605's (thier worst servo IMO) I think we can safely say servo selection is very open to personal preference.

RE: Servo Specifications for 40 size profiles
 

Standard Servos will work well.

If you beat the rudder to death, put a Metal Gear job on it.

RE: Servo Specifications for 40 size profiles
 

I've become kinda partial to the Hitec HS-5475 HB digital servos....... I recently go 4 for $120.00 shipped from [link=http://www.donalds-hobby.com]Donald's Hobby Center[/link]. So far I like them really well.

They are fairly fast, good torque, and the centering is very percise......

rcam

RE: Servo Specifications for 40 size profiles
 

Yeah, that's them. I couldn't remember their name/number

RE: Servo Specifications for 40 size profiles
 

OK, so 70 oz is way more than you need, what is the low end? 30oz, 40oz, 50oz?

Are most standard servos around 40 oz?

RE: Servo Specifications for 40 size profiles
 

Airjunky you could maybe try and get something like a 539. I love the 539's and use em on virtually all of my planes. They are a wee bit faster than the std 577 and they are strong. Nice 4.7kg BB servos. You also get another one now which I think is just a brother of the 539, think they call it a 537 or something. :D

RE: Servo Specifications for 40 size profiles
 

the 3004 is a standard servo. My point was that standards are plenty. As BH said, the hs85 are in use in many .40 sized planes as well as 225's.

I actually think a lot more about the strenth of the gear train when I pick a servo than torque, though you have to be reasonable. If you go with a small servo, get the metal gears, as the smaller plastic gears strip easily. Hitec's new composite gears seem to hold up very well so far so that helps get more strenth without the MG weight.

FWIW: here are the specs on the ones I referenced

hs85 41 oz
hs225 56 oz
hs425 (standard) 61 oz

I think you could set a 40oz min if you needed a guide, but as I said, I wouldn't use an 85 w/o metal gears.

RE: Servo Specifications for 40 size profiles
 

Thanks Gordo. I'm not buying any more hitec servos. I've bought 7 and 3 went bad installing or within 3 flights. 1 HS-85, 2 225MG's

I think I'll use 40oz as my guide.

RE: Servo Specifications for 40 size profiles
 

Standard servos work, that all you can say. They do NOT work great. 3D airplanes of any size benifit greatly from Fast servos. Its really amazing to hear people say "man i wish i could fly like that" and they have bottom dollar equipment. you check any of the big boys planes you wont find standards in any of them.

RE: Servo Specifications for 40 size profiles
 

I agree, that's why my new Composite -ARF YAK 2.6m will have JR 8611's all around. Well, not quite, the throttle will have a low end $89 120oz .18 speed JR 2721 MG servo only :):D;)

RE: Servo Specifications for 40 size profiles
 

Ive noticed a lot of post regarding hitec 5645s and hardly a post about the much quicker but slightly weaker 5625s. They are the same price.

5625
Speed: 0.17 sec/60 degrees at 4.8V
Speed: 0.14 sec/60 degrees at 6.0V
Torque: 109.7 oz/in at 4.8V
Torque: 130.53 oz/in at 6.0V
Length: 1.59" (40.6mm)
Width: 0.77" (19.8mm)
Height: 1.48" (37.8mm)
Weight: 2.11oz (60g)


5645
Speed: 0.23 sec/60 degrees at 4.8V
Speed: 0.18 sec/60 degrees at 6.0V
Torque: 143.03 oz/in at 4.8V
Torque: 164.2 oz/in at 6V
Length: 1.59" (40.6mm)
Width: 0.77" (19.8mm)
Height: 1.48" (37.8mm)
Weight: 2.11oz (60g)

RE: Servo Specifications for 40 size profiles
 

Well.........since Jess runs 225's and Paul and Gator have a huge variety of standards, and BH runs 85's and Bill and I both run standards, and doesn't Gary have standards? Well, I really don't see the servo as the deciding factor on how well you can fly a plane............

RE: Servo Specifications for 40 size profiles
 

:eek:

RE: Servo Specifications for 40 size profiles
 

Well of course not silly snake........We're not talking about big boys, there aren't any "standard" servos for a 40% plane......We're talking .40 size profiles.......And Jess isn't happy with the lifespan, not the speed or Torque. If you ask around, the VAST majority of the ProBros are useing standards and a lot of them fly circles around you and I. All we have been saying is that standards are very well suited to .40 sized profiles, not that they are the only option.

I'm not even pushing Hitecs here, just using the examples I know. He wanted to know what the standard base was for these planes. They aren't $100 servos!

RE: Servo Specifications for 40 size profiles
 

I was won over by 85MGs when I put them in the Pen Knife and had a compeletely different plane on my hands. I did the same to my Switch Blade and it was a much better plane. I've never lost one in flight and they seem pretty fast and can use the big Dubro control horns. I don't fly all day long like Jess so while he would kill them quick I will not. Add to that tham I am a mediocre pilot at best and I think that the 85 MGs are perfect for my application. I actually expected more people to tell me that running 85 MGs is crazy.

RE: Servo Specifications for 40 size profiles
 

After an UNGODLY amount of abuse in 3 Tacos my origional 85mgs are still rocking. They ahve the guts for your plane, and are very cost effective, and light. Good for me! I'm thinking of useing 85's or the new ones with the composite gears in my next special bird. But my "everyday" planes will have the lowly, practicaly useless standards.

RE: Servo Specifications for 40 size profiles
 

:eek:

RE: Servo Specifications for 40 size profiles
 

well, all I can say about the Hitec junk is that their centering is sooo baaaaad that it's unreal. You constantly have to trim the plane because the f$@#%& servo doesn't center right. Locking up in flight ain't to nice either. Just had another 225MG (that makes 3 within 2 weeks btw) go bad on me. Last Hitecs for me. Prefer any standard JR Servo over Hitecs for my profiles.
Now if you want a cool servo on your profile, get a JR 3421 Digi. Of course it's not going to cost you $29.99 but at least you have a reliable servo on your plane. Just my $0.02

RE: Servo Specifications for 40 size profiles
 

Steve, I like to build light. Standard servos are heavy/bulky. I bought the HS-85's and 225MG's because of their power to weight ratio. On paper, they should be good performers and you get good bang for the buck.

Unfortunately, as with most things, I got what I paid for. I've learned my lesson, now I'm trying to find a good replacement of the same weight/power for these.

Have any of you JR guys used 331 micros?

Ulf- those 3421's are nice, but at $85 a servo, a little out of my league.

RE: Servo Specifications for 40 size profiles
 

The Futaba 3001 (Precision BB) is my servo of choice right now.

In the past I have used S148's, the 3003's, and the 3004's, and have stripped gears, and had pots go bad on all of them. The 3003's were particularly bad.

Ironically, all of these servos are rated at 57 oz-in of torque on a 6volt battery. not 70. And they are still quicker at .19 sec than I am.

I have had no problems with the 3001's. They run about $20 a peice.

RE: Servo Specifications for 40 size profiles
 

I still prefer my futaba 9001s. At 6 volt they have 72 oz torque and .18 speed. They have a coreless motor and the good pot for excellent centering. They are a bit heavy at 1.7oz but I will live with that unless I build something really light. I have used several Hiitec 225s based on their specs. Aside from the weak gear train they are still the poorest centering servo I have ever used. I use them in my Quickie planes but full deflection of the servo only gives about 1/4" total travel so centering isn't an issue as much. 3D throws really accentuate a poorly centering servo as well as slop in the geartrain. When I first got my EF Edge I mounted some new 3004 servos. There was so much slop in the gear train, I had about 3/4" slop travel in both ailerons! I changed to the 9001s and 90% of the slop was gone. The rest was coming from the supplied linkages.
Now if only I had the skills to put them to good use! maybe I'll just have a couple of the good pilots fly my stuff tomorrow.
Later,,,Matt

RE: Servo Specifications for 40 size profiles
 

My bad on the Torque, I was going off memory.......sorta like flying by feel.......

RE: Servo Specifications for 40 size profiles
 

I've got a couple 9001's on the tail of my 1/4 scale Citabria Pro, thought I would need the torque. Seems like a nice strong, and tight servo. I used 3001's on the ailerons, and an old S148 on the throttle.

They would probably work very well on a .40 size profile too. But I don't want to pay $30 a peice for my knock-around birds. And they are only 1/100th of a second faster. Not that I would notice if they were half a second faster. However, I do know pilots that say they can tell the difference.

RE: Servo Specifications for 40 size profiles
 

I stand corrected on my memory of who has said what....I should speak only for me, and I should have learned that a long time ago!!:)

My new position: Standard servos suck, they are useless. Any standard servo should be shot, then ran over, then sunk to the bottom of the ocean. Any plane with atandard servos will clearly crash...If not dirrectly from the servo failure then from the dumbass that would even think about using it!!!! Further more, every company that makes standard servos is clearly doing the hobby a disservice and should be boycotted, as should all companies that sell them, or that recomend them for thier planes.:D:)[8D];):eek:[X(]