Aircraft Spruce and Specialty Co Forum Index Aircraft Spruce and Specialty Co
The Pilots Portal to the World
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

Fwd. mounted slave struts

 
Post new topic   Reply to topic    Aircraft Spruce and Specialty Co Forum Index -> Starduster and Acroduster
View previous topic :: View next topic  
Author Message
Bob E.



Joined: 31 Oct 2007
Posts: 147
Location: Central ND

PostPosted: Sun Feb 13, 2011 7:32 pm    Post subject: Fwd. mounted slave struts Reply with quote

I started working on my slave struts today. I am going with the forward mounted strut and will be using 5/8 round instead of streamline. I built my brackets per plans and was wondering if there should be a 1/4" thick piece of plywood attached to the aileron spar where the brackets mount or is 1/16" enough? I have 1/4" plywood on the spars where my hinges mount so that is why I'm wondering.

How have you guys done the lower end of the slave strut? The plans show a short piece of 5/8" going straight up from the lower bracket and then the long length welded at an angle and runs to the top fitting. I have also seen where it looks like the strut is just bent at the bottom.

When setting it up per plans does it just end up being a trial and error fit? looks like the strut could get close to the wing spar. How about getting the same travel on the upper aileron as the lower? Any tricks for this area? Bob
Back to top
View user's profile Send private message
jsh



Joined: 19 Dec 2005
Posts: 354
Location: Burnet, TX

PostPosted: Sun Feb 13, 2011 10:02 pm    Post subject: Reply with quote

seems like there was a revised drawing of the forward mounted slave strut brackets. I have streamline tube and they are just straight from one bracket to the other....no conflict with the spar.
Back to top
View user's profile Send private message
frank



Joined: 02 Dec 2005
Posts: 456
Location: Lynn Haven, FL

PostPosted: Sun Feb 13, 2011 10:08 pm    Post subject: Reply with quote

FWIW, the Pitts guys say there is a huge drag penalty for round slave struts. I have read both their testamonials and their alleged calculations of a 10-15 kt difference when they change to streamlined slave struts.
_________________
Cheers, Frank
Back to top
View user's profile Send private message Send e-mail
mgapilot



Joined: 03 Dec 2005
Posts: 69
Location: Woodstock, Georgia

PostPosted: Sun Feb 13, 2011 10:56 pm    Post subject: Reply with quote

For what it's worth, A Pitts model 12 friend of mine said he taped a piece of aluminum welding rod to the trailing edge of his slave struts with some clear 3M leading edge tape so I did the same with mine and haven't had the aileron feedback buzz since.

Kevin Shaw
Woodstock,GA
Back to top
View user's profile Send private message Send e-mail
Bob E.



Joined: 31 Oct 2007
Posts: 147
Location: Central ND

PostPosted: Mon Feb 14, 2011 5:18 am    Post subject: Reply with quote

I also purchased a current set of plans from Les H. when he owned it. The hole for the slave strut attach is shown to be 2.5" forward of the aileron spar. I also have a small three page print, maybe I got it from you Dave B., that shows this measurement at 3 3/8". I made a card stock pattern using the 3 3/8" measurement and when I hold it up to the aileron spar it comes very close to the wing spar thus I opted for the 2.5" measurement that the large plan sheet shows.

I don't feel a straight slave strut would work with this bracket so I am wondering if you guys with straight struts (no bend or welded angle at the bottom) have the attach holes located closer to the aileron spar. I'm betting this way will work also, I'll just have to play with it a bit.

Bob
Back to top
View user's profile Send private message
jsh



Joined: 19 Dec 2005
Posts: 354
Location: Burnet, TX

PostPosted: Mon Feb 14, 2011 5:50 am    Post subject: Reply with quote

Bob, I had an old set of plans (with the rear mounted slave struts) so I built my forward mounted slave strut brackets from the revised drawings which appeared in Starduster magazine. I will be at the hangar on Tuesday and will measure what mine are. To my recollection, my streamline slave struts are approx 1/2 inch from back of rear wing spar....and the struts are straight, no bends, etc.
Back to top
View user's profile Send private message
Bob E.



Joined: 31 Oct 2007
Posts: 147
Location: Central ND

PostPosted: Mon Feb 14, 2011 9:54 am    Post subject: Reply with quote

Thanks John,

I don't think I could get by with a straitht strut with this bracket so I'm thinking your attach point must be closer to the aileron spar.

How about ballancing them. The plans show to fill the short 5/8" tube with lead shot and epoxy to ballance the ailerons. Is this necessary?
Back to top
View user's profile Send private message
John Singer



Joined: 03 Dec 2005
Posts: 131
Location: New London, NH

PostPosted: Mon Feb 14, 2011 12:05 pm    Post subject: Reply with quote

Bob
If you are concerned about additional drag from round tubing, you can
convert the round tube to streamline shape by inletting * a half round grove and epoxying a balsa wood strip to the round tube, Shape it to streamline contour, cover with lightweight cloth and paint. Weight increase is very small.
John Singer

* Gunsmiths use such a tool to inlet rifle barrels into a stock.
_________________
John Singer
Back to top
View user's profile Send private message Send e-mail
Starduster History



Joined: 30 Nov 2006
Posts: 735
Location: St. Helens, Oregon

PostPosted: Mon Feb 14, 2011 2:14 pm    Post subject: FWD Mounted Aileron Struts Reply with quote

Bob give me a call on this if you get a chance. Dave
_________________
Dave Baxter
Starduster History
Back to top
View user's profile Send private message
jsh



Joined: 19 Dec 2005
Posts: 354
Location: Burnet, TX

PostPosted: Mon Feb 14, 2011 4:43 pm    Post subject: Reply with quote

Bob, the only control surface I balanced was the elevator.
Back to top
View user's profile Send private message
AndrewK



Joined: 09 Jun 2009
Posts: 28
Location: Dallas, TX

PostPosted: Sat Feb 19, 2011 6:11 pm    Post subject: Reply with quote

frank wrote:
FWIW, the Pitts guys say there is a huge drag penalty for round slave struts. I have read both their testamonials and their alleged calculations of a 10-15 kt difference when they change to streamlined slave struts.


Saw this on another board I frequent recently. It is older footage but still very good. Shows how drastic the difference between round and streamlined shapes can be.

http://www.youtube.com/watch?v=ftq8jTQ8ANE
Back to top
View user's profile Send private message
frank



Joined: 02 Dec 2005
Posts: 456
Location: Lynn Haven, FL

PostPosted: Sat Feb 19, 2011 8:06 pm    Post subject: Reply with quote

I have not used this in years:

"QED"

QED is an initialism of the Latin phrase quod erat demonstrandum, which means "what was to be demonstrated".

In this case VERY effectively so.

So make em streamlined!
_________________
Cheers, Frank
Back to top
View user's profile Send private message Send e-mail
davet



Joined: 02 Dec 2005
Posts: 588
Location: Indiana, Trafalgar

PostPosted: Sat Feb 19, 2011 8:43 pm    Post subject: Reply with quote

An excellent education in a few minutes.

I guess I'll scrap my plan to use 1/4" round rods for bracing the underside of the horizontal stabilizer. I had always thought they would save weight over the streamlined struts, and surely wouldn't increase drag, due to them being only 1/4" diameter.
_________________


Dave Tharp
Cardinal RG
Starduster Too (building)
Back to top
View user's profile Send private message
Bob E.



Joined: 31 Oct 2007
Posts: 147
Location: Central ND

PostPosted: Sun Feb 20, 2011 7:39 am    Post subject: Reply with quote

Yes, that is very eye opening. jsh emailed the clip to me a few days ago and there is now some streamline on its way to me.

Davet- I thought of the tail brace wires also. I had some lowers made up out of some 5/16" stainless rod as the plans say something to the effect of "make out of at least 5/16" as damage from rocks may occure". Thinking about it now I can't see why 1/4" wouldn't be enough. I think my old Citabria only had one 1/4" rod top and bottom. I'm going to keep the rods but may change to 1/4".

Do any of you other guys have wires on the bottom of you tail? Or, have any of you changed from the streamline tube to wires and noticed a big difference? How about wire size? 1/4" or 5/16"??
Back to top
View user's profile Send private message
frank



Joined: 02 Dec 2005
Posts: 456
Location: Lynn Haven, FL

PostPosted: Sun Feb 20, 2011 10:52 pm    Post subject: Reply with quote

Bob E.
Our AD2 had streamlined tubing beneath the horizontal stab, streamlined flying wires above. It seemed the right combination for potential pebbles, rocks, or larger objects coming at it from the ground side. Please do not ask about landing lights or unusually tall PVC runway boundary markers!
_________________
Cheers, Frank
Back to top
View user's profile Send private message Send e-mail
Display posts from previous:   
Post new topic   Reply to topic    Aircraft Spruce and Specialty Co Forum Index -> Starduster and Acroduster All times are GMT - 7 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by Aircraft Spruce Worldwide Distributor of Certified and Homebuilt Aircraft Supplies