smoking joe

What rib should I start spoilers from and end. I wanted to use the simple T/E stock and what size would you recommend. Smoking Joe

Tall Paul

Were I to do another GL wing, I'd add spoilers about like those on the GP Spirit.
They'd be made of 1/8" soft balsa, 1" chord, 3-bay span, outboard end 1 bay in from the poly break.
Kevlarâ„¢ thread to pull open, small gumband to close.
A mini servo has more than enough grunt, as the airlow over the wing has relatively little force at GL speeds.
The movement.. I use a 3-position switch on the several planes I have spoilers on.. closed, 1/2 open and full open. 1/2 open is more than enough to bring them down.
Dr. Drela OTOH on his competitive 2Ms uses enormous spoilers, 28"x1-1/2" on the Allegro_E_Lite for instance, but his wings are seriously stronger than the GL and he competes in the upper echelons where getting down NOW is important.
The support structure: extend the leading edge sheeting to the dihedral break.
Add the shear webs shown in another thread, and put the spoilers aft of the l.e. sheeting.

smoking joe

Tall Paul. Where do I find the thread on the shear webs and sheeting, also I'm making this a 3 piece wing, although my flying field is next door, I drive a Pulsar any may go else where to fly. Thanks for all your help. Smoking Joe

kamakasi

My Feedback: (3)

I'm in agreement with Tall Paul. Except that I would use 1" trailing edge stock. I you let the leading edge of the stock stand tall about 1/32" you can sand it to the airfoil without losing any stiffness. I also use a small spring attached to the leading of the wing to pull the spoiler closed. This way I never have a rudder band to replace. The reason you want to hold he spoiler closed is that if you wind up with a tear in the bottom of your covering it can produce a positive pressure inside the wing thus forcing the spoiler open.

Tall Paul

It's the "hinging rudder & elevator on Gentle Lady" thread here..

Tall Paul

Because the spar in the GL and Electra wing interfere with the usual set-forward of the spoiler, this method will work for these to permit the maximum up deflection..

aeajr

My Feedback: (2)

I don't have a GL but I do have GP Spirit and a Sagitta 600, both with spoilers. I will post some photos that might be helpful.

Both have the spoilers set at the back of the spar, where the sheeting ends.

These photos are of the Sagitta. I have these connected by strings to a single servo, Hitec HS-81, in the fuse.

aeajr

My Feedback: (2)

These shots are of the Spirit. In the Spirit I have servos in the wings operating the spoilers.

smoking joe

aeajr the pics of the spirit will help that is my next project they appear to be 3 bays long and 1" te stock smoking joe

aeajr

My Feedback: (2)

The spoilers in the Spirit are 3 bays by 1 1/4 inches operated by servos. They only open to about 60 degrees because the arms on the servos are very short. However that is adequate to set the Spirit down. It is a floater, like the GL. I don't fly it in competition.

I originally put them in to help me get out of strong thermals as I almost lost the plane once during an early flight. The spoilers would help me pull out of strong lift.

The Sagitta spoilers are string operated and go full 90 degrees. The Sagitta is a faster plane so the extra angle helps. I might fly this one in competition. I have never seen the spoilers open on a launch but I could see how that could happen. The only thing holding them closed is a 1/4 oz weight on the spoiler, and airflow. I have looped the plane during pop-offs on launches and have not noticed the spoilers opening in this situation, but I suppose it could happen.

Frankly I found the strings easier to balance than the servos as both planes have the spoilers on one channel. They both work just fine. Between the weight on the spoiler lid in the Sagitta, and the servos in the Spirit I figure the string method is similar in weight to the servos in the wings as those servos are about 1/4 oz.

These links are to discussions on spoilers in the Spirit that you may find useful.

http://rclibrary.com/viewtopic.php?p=127#127

http://www.rcuniverse.com/forum/fb.asp?m=1375310

http://www.rcgroups.com/forums/showt...7&goto=newpost

aeajr

My Feedback: (2)

This link is to a photo series by a person adding spoilers to a wing.

http://66.55.23.12/gallery/spoilers1/index.html


This is an article on spoilers
http://www.skybench.com/report/spoilers.html

Good luck with your project. We would love to hear progress reports. Perhaps you can take some pictures along the way and post them so your learning can help others.

Bumstead

My Feedback: (2)

Tall Paul, your avatar says California but, you must have spent some time in Pittsburgh
Gumband...that's so burg like.
Never heard it anywhere else