rc-plane

I am new to big planes so I need some advice. I was wondering what type of servo I need for the throttle? For my glow planes I usally have a standard cheap servo but I was wondering with the big planes do I need more? High speed maybe?

I dont have a clue so please help!

I almost forgot. Is there a new version of the 5955TG I think its the 7955TG. Whats the difference. Its only like $5 more.

Thanks

rc-plane

camss69

My Feedback: (46)

The 7955 has a higher resolution, I think that's the only difference, same motor, same speed and torque rating.

You can use a standard servo, popular throttle servo is the hitec 225mg, I like the JR 8411, I'm currently using a JR DS821 which seems to work well also.

Speed is good for throttle servos.

MetallicaJunkie

i like to use the hitec 225 mg's also known as mighty minis, i chose metal gear to help withstand the vibrations of a gas engine http://www3.towerhobbies.com/cgi-bin...mini&search=Go

bgold

I read Joe Hunt making the argument that the throttle was every bit as important as any flying surface and you should use the same quality servo there as anywhere on the plane. When reading his whole reasoning it certainly made sense.

Zeeb

My Feedback: (41)

There's usually quite a discussion when talking about what servo to use for the throttle i.e. standard, analog, digital, nylon gear, metal gear, full size or mini.... Get the idea?

You'll just have to read the responses and pick something you like, but I personally would stay away from anything that is not full size and does not have metal gears. I stressed over the question and since I've been quite impressed with the Hitec digitals I've started using, I elected to use the 5625 Hitec so I could program it's throws, center and get me a high ATV setting on the throttle servo for better control especially just coming off the engine idle where the gassers are really sensitive. Depending on your engine and install, there's only so much that can be done to maintain a good mechanical advantage/throw relationship and that's where the programmable servos come in handy.

As for the differences between the 7955 and the 5955; the biggest difference right now is that the 7955's aren't going to be available for some time yet. I've decided to wait for these servos for the new Comp-Arf I have sitting here since they are capable of a 2048 resolution as well as overload protection. So they can be setup such that if a servo should get bound up or stall, it won't pull a whole bunch of electrical power and possibly compromise your system.

You also don't need a 300 plus ounce servo on the throttle, but if you want to go that way to keep them all the same and the money isn't an issue, then go for it....

JMHO, YMMV....[8D]

BaldEagel

There is a reasoning that you should not use digitals on the throttle, due to the vibration constantly trying to move the servo back and forth from its current position and the battery drain that would impose as they have a higher holding power, this is not my thory but on Quique Simozini's web site. Personnaly I use a standard metal geared servo, because I have some, can't see any reason for not using small size servo's as long as they have the power.

I set my servo's up so that at closed throttle (stopped engine) the servo arm is pointing up the throttle rod, this gives me a slow opening on the beginning of the movement, where most of the effective throttle control is and increasing movement up the stick position, with a throttle curve in the Tx as well you can get a linier reponce, of course the best way would be to set the whole thing up so that you get half revs at half stick position, that's half the revs between idle and flat out.

Mike

Tired Old Man

My Feedback: (1)

I like to match the throttle servo speed to the flight surface speed. I can't stand it when the throttle lags behind the rest of a plane in a maneuver. Especially in a hover!! I've used minis, standards, digitals, analogs, coreless, metal, and nylon gears. So far I prefer a coreless or digital servo with metal gears in standard sizes.

Now if you've just gone out and put a grand or three in your first gasser/giant, why skimp on the throttle servo? IMO it's just as important as any other servo in the plane.

Disclaimer: Your experiences may be different from mine

rc-plane

You know yall sure dont make this easy!

Zeeb

My Feedback: (41)

I warned you....

Flyjets

My Feedback: (51)

My Take

Torque is not that important anything 60oz works.

Speed is kinda important.

Position Accuracy is the most important as one or two clicks off at each throttle movement might Kill a Gasser.

Case size if the Servo is near any Heat Source the size of the Case should be standard side. I have seen the Mini and Sub Mini fail from heat.

Digital is unnecessary if U can find an Analog that meets the above requirements.

Ian

rc-plane

Thanks

JoeAirPort

My Feedback: (41)

I'd go HD on the throttle. Lot's O' vibrations. I used to think mini's were fine till I added up the damage risk. Now they are 5945 andr 5955 on my two gassers.

rc-plane

I just realized I have some DS 821 digitals.....how would that work?

rc-plane

????

Zeeb

My Feedback: (41)

You're just gonna have to go back and read the responses you've already gotten and decide for your self as you'll not get a consensus of opinion on using those, sorry 'bout that...

rc-plane

Thats what I wanted to know I just forgot I had some

Starfighter

My Feedback: (78)

Hi: My name is Ken, and here's my 2 cents:

Install a hi-speed NYLON gear Analog of 50+ oz. in. rating. Why NYLON vs METAL:
The NYLON will have zero backlash/tighter deadband and more accurate centering after displacement(input). The metal gear is not as tight, and will not be as accurate. Also, DO NOT install digital on the throttle. Believe it or not, a digital on the throttle is not as accurate, will consume more power as well. If you must go digital, then use one with NYLON gears.(can't emphasize enough).
Don't believe me? Well, I've been flying giant scale since the "Olden" days (when all we had were 40 -60 oz. in. analogs w/ brittle nylon gears), and have seen the hobby/industry grow. You see, been doing this for 50+ yrs. now. So, I feel that I can make a suggestion based on considerable experience. (Been a Pattern flyer for years as well. Remember Jason when he was 12 and flying at one of our events here many years ago [no, he didn't win].)
Also, what if I tell ya the none other than QuiQue Somenzini recommends the same (Heard of him?. Well, SURE you have.) But, take this for what is is, Advice. It is up to you to decide which one from all the suggestions you have received, is best for your needs.
Good luck with your project.
Ken (Starfighter)

rc-plane

Thanks for your comment and yes I have heard and look up to all of those people. Like I said I just found them so I decided to ask about them.

Thanks for your help

Tired Old Man

My Feedback: (1)

The 821's will be just fine. I might be one of the lucky ones but in 35 years of r/c I've never had a throttle servo failure. Linkage yes, servo, no. When I don't have anything else laying around I'm quite content with an 821. Typically I'll use an 8411, 8611, 0r 4721, but the 811 is acceptabel for me as well. The firstthree are massive overkill for torque but perfect for speed and precision and matched to the rest of my servos. One is metal geared, the other two nylon. If your linkage is good and the servo correctly mounted the gear type won't really matter.

Different strokes for different folks I guess. I'm not Que Que for sure.....

rc-plane

Does anybody have a servo suggestion for Hitec because I want to have all hitec

JoeAirPort

My Feedback: (41)

Post #12

UH60 Crewdog

I use a Standard Servo from Futaba S3003, Its cheap and reliable. I use a throttle cable for my 26CC Gasser for the vibration. I'm in the military so the budget does matter. I have never had a problem with this set up. Depending on how far you set the cable on the horn and the throttle on the engine make a big difference on the reaction speed of the engine. Even though I have a slower servo it doesnt have to move far at all to hit open throttle thus fast responce.

Good luck and happy flying