Servo Question
06-07-2008 | 08:33 PM
#1
Thread Starter
Member
Joined: May 2007
Posts: 30
Likes: 0
Received 0 Likes
on
0 Posts
From: ReginaSaskatchewan, CANADA
Servo Question
I'm building a Dynaflite Super Decathlon, with a 89" wingspan. The instrustions say to use 5 High Torque Servos. I would like to know which servos would be the better ones to use. This is my first larger plane and i'm not sure which is best. I was told maybe try servos from Spectrum DS821. But I don't know anything about Spectrum. Are these good Servos, or should I look at different ones?
http://www.spektrumrc.com/Products/D...ProdID=SPM3702
http://www.spektrumrc.com/Products/D...ProdID=SPM3702
06-07-2008 | 09:23 PM
#2
Senior Member
Joined: Dec 2001
Posts: 2,889
Likes: 0
Received 0 Likes
on
0 Posts
From: Bemis,
NM
RE: Servo Question
The DS 821's are pretty darn good sport digitals. I've been using two on split elevators. You may not need 5 digitals onboard, but they are a definite asset on elevator. You can use analog's on the other control functions. A good strong economy analog is the HiTec 625 metal gear. You can check out HiTec specs here. > http://www.servocity.com/html/hitec_servos.html
You can also find some pretty good deals on ebay, when dealers split up the Spektrum sets, and sell new DS-821's in sets of 4.
> Jim
You can also find some pretty good deals on ebay, when dealers split up the Spektrum sets, and sell new DS-821's in sets of 4.
> Jim
06-09-2008 | 09:08 AM
#7
My Feedback: (6)
RE: Servo Question
ORIGINAL: GeeBeeJim
The DS 821's are pretty darn good sport digitals. ...
The DS 821's are pretty darn good sport digitals. ...
Quoted from here: [link]http://spektrumrc.com/Articles/HobbyWire.aspx[/link]
New Guidelines for DS821 Servo Use
Tuesday, February 20, 2007
The DS821 servo is a powerful, accurate sport digital servo recommended for RC airplane applications up to 1.20-size. For helicopters, the DS821 operates best with 30-size glow models, and up to 50-size electric. Loads and vibration in larger models may cause premature failure of the servo resulting in damage or injury to property and persons.
Important: Do not use liquid thread lock with the DS821 servo!
Do not use any form of liquid thread lock to secure the servo arm screw to the output shaft of the DS821 servo. Chemicals in these liquids react with the polycarbonate gear set causing the plastic to become brittle, fracturing the final output gear.
Tuesday, February 20, 2007
The DS821 servo is a powerful, accurate sport digital servo recommended for RC airplane applications up to 1.20-size. For helicopters, the DS821 operates best with 30-size glow models, and up to 50-size electric. Loads and vibration in larger models may cause premature failure of the servo resulting in damage or injury to property and persons.
Important: Do not use liquid thread lock with the DS821 servo!
Do not use any form of liquid thread lock to secure the servo arm screw to the output shaft of the DS821 servo. Chemicals in these liquids react with the polycarbonate gear set causing the plastic to become brittle, fracturing the final output gear.
Rafael
06-09-2008 | 09:57 AM
#8
RE: Servo Question
With larger models you're typically looking at a high torque metal geared servo with at least 100 oz/in of torque. Hitec 645 MG's are good as well as JR ST125MG servos. Don't skimp on cheap servos, your airplane will thank you. 
While those Spektrum servos are great servos, they are not well suited to giant scale.
While those Spektrum servos are great servos, they are not well suited to giant scale.
