A Discussion on Servo Usage
03-31-2008 | 06:29 AM
#1
Thread Starter
Senior Member
A Discussion on Servo Usage
I'm terribly confused, so perhaps you more experienced guys can help me out. I have two classic pattern planes with the standard Futaba S3004 servos. Since the servos back in the day weren't very fancy I figured these would be fine. Recently, I've looked at some recommended setups for slower and slightly smaller aircraft with similar sized control surfaces. Every one of these are recommending servos with a minimum of 72 oz/in of torque. Considering the 3004's only have 44.4 oz/in of torque, are my servos an accident waiting to happen, or is this a marketing ploy? [
]
]
03-31-2008 | 09:10 AM
#2
Senior Member
RE: A Discussion on Servo Usage
Nathan,
Good question about servos.
I recently returned to RC after more than 20 years away and so much has changed. We used to fly .60 size "pattern planes" and Quickie 500 racers with servos that were weaklings as compared to the torque ratings of modern servos. How did we ever get away with it? My suggestion would be to use your standard Futaba S3004 servos for throttle on your classic pattern planes, and any other planes you may build. For your control surfaces, a good choice would be the Futaba S3152 Servo Digital Standard Hi-Torque. SPECS: Speed: .22 sec/60° @ 4.8V, .18 sec/60° @ 6V Torque: 69 oz-in @ 4.8V, 87 oz-in @ 6V Tower has these now listed at $29.99 Those old Kraft servos I used years ago were priced at about $35. That would be more than 100 bucks in today's dollars.
Regards
JC
Good question about servos.
I recently returned to RC after more than 20 years away and so much has changed. We used to fly .60 size "pattern planes" and Quickie 500 racers with servos that were weaklings as compared to the torque ratings of modern servos. How did we ever get away with it? My suggestion would be to use your standard Futaba S3004 servos for throttle on your classic pattern planes, and any other planes you may build. For your control surfaces, a good choice would be the Futaba S3152 Servo Digital Standard Hi-Torque. SPECS: Speed: .22 sec/60° @ 4.8V, .18 sec/60° @ 6V Torque: 69 oz-in @ 4.8V, 87 oz-in @ 6V Tower has these now listed at $29.99 Those old Kraft servos I used years ago were priced at about $35. That would be more than 100 bucks in today's dollars.
Regards
JC
03-31-2008 | 09:47 AM
#3
My Feedback: (1)
RE: A Discussion on Servo Usage
Another option are the JR DS821 digital servos. They are supposed to be a bit better than the Futaba 3151's and 3152's (I own all three).
http://www.horizonhobby.com/Products...ProdID=JRPS821
The good news is that the DS821's come with the Spektrum radios. Lots of people who are buying the Spektrum radios want larger servos for giant 3D planes, etc. So, they are selling brand new sets of four DS821's on the 'Bay. I won four of them a few weeks ago for $59.99; that's $14.99 each.
Just search for "DS821" and you'll see a bunch of auctions.
David
http://www.horizonhobby.com/Products...ProdID=JRPS821
The good news is that the DS821's come with the Spektrum radios. Lots of people who are buying the Spektrum radios want larger servos for giant 3D planes, etc. So, they are selling brand new sets of four DS821's on the 'Bay. I won four of them a few weeks ago for $59.99; that's $14.99 each.
Just search for "DS821" and you'll see a bunch of auctions.
David
03-31-2008 | 09:48 AM
#4
Senior Member
My Feedback: (14)
RE: A Discussion on Servo Usage
It depends.
If you're going to fly 3D models with very large control surfaces and huge amounts of throw, you need the modern hi torque servos.
If you are going to fly more or less traditional models, even old pattern models, you don't need anything more than what you already own.
Remember the KPS-14 & 15 servos that many of us used years ago? I never had a failure that wasn't caused by a dumb thumb or hanger rash problem. Ditto the Futaba FPS-28 or the Orbit/Micro Avionics PS3 and PS4 servos. I ran the hottest .60 engines that I could afford back then and I flew a lot.
If you can afford the more expensive servos available today, you will be pleased with their performance, but whether they are worth the investment is purely subjective.
Your FPS-3004 servos are nearly twice as strong as the old Kraft servos that many flew in pattern in the old days.
Ed Cregger
If you're going to fly 3D models with very large control surfaces and huge amounts of throw, you need the modern hi torque servos.
If you are going to fly more or less traditional models, even old pattern models, you don't need anything more than what you already own.
Remember the KPS-14 & 15 servos that many of us used years ago? I never had a failure that wasn't caused by a dumb thumb or hanger rash problem. Ditto the Futaba FPS-28 or the Orbit/Micro Avionics PS3 and PS4 servos. I ran the hottest .60 engines that I could afford back then and I flew a lot.
If you can afford the more expensive servos available today, you will be pleased with their performance, but whether they are worth the investment is purely subjective.
Your FPS-3004 servos are nearly twice as strong as the old Kraft servos that many flew in pattern in the old days.
Ed Cregger
03-31-2008 | 01:06 PM
#5
Thread Starter
Senior Member
RE: A Discussion on Servo Usage
Cool. Since I'm into pattern (obviously) I always use little throw and keep maneuvers smooth and broad. I'll end up changing them out anyway, but really wanted to know if it was wise to fly in the meantime. I'm sure glad I won't be forced to ground two aircraft at the beginning of the season.
Have fun guys - Spring is here!!
Have fun guys - Spring is here!!
