Go Back  RCU Forums > RC Airplanes > RC Jets
Reload this Page >

Composite Roo 2 or 4- 8411 for elevon?

Notices
RC Jets Discuss RC jets in this forum plus rc turbines and ducted fan power systems

Composite Roo 2 or 4- 8411 for elevon?

Old 03-06-2002, 12:51 PM
  #1  
johnnyjet
Thread Starter
My Feedback: (4)
 
Join Date: Dec 2001
Location: Prattville, AL
Posts: 418
Likes: 0
Received 0 Likes on 0 Posts
Default Composite Roo 2 or 4- 8411 for elevon?

Composite Roo 2 or 4- 8411 on the elevons

Hi I am finishing up a composite Roo I pick up at fl jets. (Thanks Don)
My questions are 4 JR 8411 over kill for the elevons or will 2 JR 8411 do as well, like the old Roo?
I really need some help with this one.

Thanks

Johnny Klinner

AKA Johnnyjet
Old 03-06-2002, 01:23 PM
  #2  
Jackjet
Senior Member
My Feedback: (1)
 
Jackjet's Avatar
 
Join Date: Dec 2001
Location: Apple Valley, CA
Posts: 1,137
Likes: 0
Received 0 Likes on 0 Posts
Default Composite Roo 2 or 4- 8411 for elevon?

Johnnyjet,
use 4 of them-your aircraft and turbine are worth it.


Jackjet
Old 03-06-2002, 02:06 PM
  #3  
CobraJet
My Feedback: (4)
 
CobraJet's Avatar
 
Join Date: Feb 2002
Location: Parker, CO
Posts: 536
Received 1 Like on 1 Post
Default Composite Roo 2 or 4- 8411 for elevon?

Johnny,
You can also use the 8231's, 4 of 'em. JR lists them as the ideal choice for ailerons on an precision pattern airplane or jet. They're rated at 88 oz/in which when ganged will give you 176oz/in. ~$90.
Old 03-06-2002, 02:08 PM
  #4  
Gary Jefferson
My Feedback: (167)
 
Join Date: Jan 2002
Location: Lebanon OH
Posts: 1,359
Likes: 0
Received 1 Like on 1 Post
Default Composite Kangaroo

Johnny, I bought one of the composite Kangaroo's at Florida jets as well and Don and Mark at Planes Plus both recommended using 4-8411's for the elevons. I don't know if it is required but that is what they recommended to me. I am using 4 myself.
I don't want to find out the hard way that I should have used 4 instead of two. Like JackJet said it's worth the extra money.
Just so you know, if you call Planes Plus you can probably get the 8411's for about that same price. I bought 8 of them recently for $100.00 each I think.
They have them by the boat load because they setup Giant scale planes which are ganged and require testing a number of servos to get them to match. Gary Jefferson
Old 03-06-2002, 02:13 PM
  #5  
Pete S-RCU
 
Join Date: Dec 2001
Location: Prior Lake, MN
Posts: 694
Likes: 0
Received 0 Likes on 0 Posts
Default 8411's

I use two on my Roo, plenty of power.
If you're using four for safety reason's, you have twice the chance of failure, if one fails and the other is fighting it who wins?
Will the stalled servo drain the batt pak?
What position will it fail in?
In short its anybody's guess which is better, servo failure is very uncommon, and if you pay attention they usually give indications before they fail.
Plus two is cheaper.
My .02 worth.

Pete Stapleton
Old 03-06-2002, 02:43 PM
  #6  
bkf
Senior Member
My Feedback: (5)
 
Join Date: Jan 2002
Location: Rochester, NY
Posts: 1,506
Likes: 0
Received 0 Likes on 0 Posts
Default Composite Roo 2 or 4- 8411 for elevon?

Johnny: Is it going to be split elevons? Bkf
Old 03-06-2002, 02:46 PM
  #7  
Modelman
Senior Member
My Feedback: (7)
 
Modelman's Avatar
 
Join Date: Dec 2001
Location: Fisher, IL
Posts: 415
Likes: 0
Received 0 Likes on 0 Posts
Default Composite Roo 2 or 4- 8411 for elevon?

BKF and Pete,

The composite Roo has split elevons unlike the Sheeted Roo.

Craig
Old 03-06-2002, 02:50 PM
  #8  
bkf
Senior Member
My Feedback: (5)
 
Join Date: Jan 2002
Location: Rochester, NY
Posts: 1,506
Likes: 0
Received 0 Likes on 0 Posts
Default Composite Roo 2 or 4- 8411 for elevon?

Thanks Craig! I did not know that. So much for the stone age me. Bkf
Old 03-06-2002, 03:02 PM
  #9  
lov2flyrc
My Feedback: (24)
 
lov2flyrc's Avatar
 
Join Date: Dec 2001
Location: Daytona Beach
Posts: 6,102
Likes: 0
Received 0 Likes on 0 Posts
Default Composite Roo 2 or 4- 8411 for elevon?

Craig,
I am using 2 8411's, 4 is way overkill! But if you got the $ then go for it....If $ is a concearn, use 4 of the cheaper digital hitec servos, you can get 4 hitecs for the price of 2 8411's. probably dont need more than 65-70 oz/in of torque for each half of an elevon but definitly go digital!
just my $.10
Todd
Old 03-06-2002, 04:56 PM
  #10  
Modelman
Senior Member
My Feedback: (7)
 
Modelman's Avatar
 
Join Date: Dec 2001
Location: Fisher, IL
Posts: 415
Likes: 0
Received 0 Likes on 0 Posts
Default Composite Roo 2 or 4- 8411 for elevon?

Hi Todd,

I believe your reply above to me (Craig) was meant for Johnnyjet.

But your reply does raise a question for me. As Johnnyjet is building the composite Roo, many have replied regarding using ony two BrandXXX servos. The composite Roo arrives set-up for four servos (two pre-cut and skin hinged elevons/servo wells per wing).

Those of you who are recommending two servos... are you basing your reply on the sheeted wing version of the Roo? Or are you implying that the composite Roo can somehow have it's two control surfaces per wing glued together and driven by only one high power servo?

Thanks all,

Craig
Old 03-06-2002, 05:18 PM
  #11  
tamjets
My Feedback: (2)
 
Join Date: Dec 2001
Location:
Posts: 4,586
Likes: 0
Received 0 Likes on 0 Posts
Default 8411's

I and the rest of the Roo gang in San Jose fly with 2 8411's.
Between us 4. We had log in at least over 200 flight. We didn't notice any kind of problem.
We clue split elevon to one piece.
Tam
Old 03-06-2002, 05:43 PM
  #12  
lov2flyrc
My Feedback: (24)
 
lov2flyrc's Avatar
 
Join Date: Dec 2001
Location: Daytona Beach
Posts: 6,102
Likes: 0
Received 0 Likes on 0 Posts
Default Composite Roo 2 or 4- 8411 for elevon?

Craig,
Sorry, your right my post was intended for johnnyjet. To answer your question, you can glue the split elevons together and use one servo instead of two, in that case use the 8411's. If using split elevons then there is no need for the amount of torque the 8411's provide and suggest you use a less expensive servo like the new hitec digi's, you can buy TWO hitec 5625 servos for the price of one JR8411 with no problems. Everyone has their own opinion on which setup is better (one servo or two) but I personally have had no problems with the one servo setup. Two does offer redundancy but limited, depending on how the servo fails...Hope this clears some things up...
Todd
Old 03-06-2002, 06:13 PM
  #13  
johnnyjet
Thread Starter
My Feedback: (4)
 
Join Date: Dec 2001
Location: Prattville, AL
Posts: 418
Likes: 0
Received 0 Likes on 0 Posts
Default Composite Roo 2 or 4- 8411 for elevon?

Thanks all

That is the information I needed.
I have 3 new 8411 now and could pick another this weekend.
My major concern was the hassle of setting up the 4 servos in the wing and aligning them perfect.
I don’t want to use 4 channels of the receiver and I am not ready to try the matchbox (yet!).

I do appreciate all the good answers.

Tam you may not remember but you were delivering a split exhaust pipe in front of the jetcat tent at
Fl jets I walked over took a look and said “too cool”. O well.

Johnny
Old 03-07-2002, 04:24 AM
  #14  
tamjets
My Feedback: (2)
 
Join Date: Dec 2001
Location:
Posts: 4,586
Likes: 0
Received 0 Likes on 0 Posts
Default Composite Roo 2 or 4- 8411 for elevon?

[
Tam you may not remember but you were delivering a split exhaust pipe in front of the jetcat tent at
Fl jets I walked over took a look and said “too cool”. O well.

Johnny [/B][/QUOTE]

John,
I run across so many peoples. Hard to remember everyone by name. Unless we do some kind of special project.
Only things I can remember from FL Jets is RAIN and RAIn and RAin and Rain and rain.

Tam
Old 03-07-2002, 01:44 PM
  #15  
c/f
My Feedback: (1)
 
Join Date: Jan 2002
Location: evansville, IN
Posts: 883
Likes: 0
Received 9 Likes on 8 Posts
Default JR 4721

Iv'e been using this servo (2) for past year in my planes plus ARF roo I bought @ Superman 00.. 128oz if I remember correctly.
Duall ball bearinged and coreless motor. My roo uses 1/16" up elevons for trim @ most. It is 17lbs dry with AMT Mercury for power... The dual setup is all the safety margin you need....I've seen many of digital servo powered giant scale AND helis, destroyed because the owners were not concious of the rapid discharge curve they impose on battery packs.
IMHO this model is a trainer, K.I.S.S. , the weakest link has got to be the squashed rudder fins. any slop that sets up a high speed ocillation would surely put this model in the ground versus digital servo selection over premiums......02

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.