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Old Jan 20, 2003, 12:44 AM
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Wayne's Gulp Pictures #1

Here are a couple of images of my just finished Gulp DS. I am still finishing the construction article.
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Old Jan 20, 2003, 12:45 AM
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Wayne's Gulp Pictures #2

Here is image #2.
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Old Jan 20, 2003, 12:49 AM
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Wayne's Gulp Pictures #3

Here is Image # 3. The best place to be when I fly may be...behind the 8-ball. Thanks to Dan Borer for the Excellent Graphics!
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Old Jan 20, 2003, 12:58 AM
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Wayne's Gulp Pictures #4

Here is the half covered wing showing the RAD installation. This is a very good combination. RADs are 32 degree using HS-81 Servos.

Note Ballast Tube installation above RADs. 0.5 inch Carbon tube from Aerospace Composite Products.
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Last edited by LWThompson; Jan 23, 2003 at 10:34 PM.
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Old Jan 20, 2003, 01:04 AM
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Wayne's Gulp Pictures #5

Here is a picture of the lead for the Ballast, the marked location of the tube and at the very top is the new 0.5 inch Carbon tube. Also note my first attempt at carbon fiber lamination in the elevons at the bottom of the picture.
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Old Jan 20, 2003, 01:13 AM
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Wayne's Gulp Pictures #6

Here is a modification to the Gulp DS. I used a 0.5" square Basswood block to have two tow hooks. One in front for Bungee Launcher and one just in front of the Spar for hi starts. And no I am not going to try to thermal it. I think it adds some strength to the bottom and I was not concerned about weight.

Also you can see the installed RAD pocket in the elevon. The small hole behind the pocket is for the hardened wire which I chose not to cut off. It does however make for a nice alignment.
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Old Jan 20, 2003, 01:25 AM
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Wayne's Gulp Pictures #7

Here is another modification to the Gulp DS. I laminated the tail with a carbon fiber veil. So does this make it a "veil tail". This is so light that you can see through it. Note scrap on left and lettering underneath.

Note to self... do not use wax paper for this again.
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Old Jan 20, 2003, 01:33 AM
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Wayne's Gulp Pictures #8

Here is a close-up of the RAD / Servo installation using HS-81. You can also see the Gorilla glue I used on the carbon pultruded spars and the center spar joint which Steve Drake explained very well in the instruction manual. I also filled the rest of the center spar cavity with slow epoxy since weight was not a big concern. No Stress risers here.

Also note that the servo lies just outside a faint line where the fuse ends. This together with the servo wire being folded back and then out will allow me to get the servo out easily without having to take apart the wing/fuse which is 3m 77'ed together.
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Old Jan 20, 2003, 01:47 AM
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Wayne's Gulp Pictures #9

Here is the backbone of the Gulp DS. The wing cord centerline is left to right (or visa versa). The Top and Bottom pultruded carbon spars each have a center joint that I made with the provided uni-direction carbon tow and slow epoxy. I first glued the two wing halves together with 5 min. epoxy (extra dihedral added). Then I epoxied the bottom spars together, taped up the joint with masking tape, and laid it on the bottom of the wing to cure. Same for top. Then I laid in a bead of Gorilla glue the full length and presed in the spar. After that cured, I filled in the center spar joint cavities, top and bottom, with epoxy to the top of the foam. Again, weight was not my concern.
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Old Jan 20, 2003, 02:00 AM
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Wayne's Gulp Pictures #10

Here is a shot of the Carbon laminated elevons. No, I do not own stock in a carbon fiber company; this was just me doing my engineering thing. I think Steve's kit for laminating the elevons would have worked better than what I did. I purchased 2" bi-directional laminate and epoxied it the the 1.75 inch wide elevons on the top only. Three coats of epoxy to get it kinda smooth. I did not have a vacume bagger so I just laid it face down on some wax paper. When it became firm but not rigid, I trimmed it as close as possible; ruined the siccors. Two days later, I sanded it to shape. I used Ultracote covering that looks like carbon fiber for the bottom.

Note to self... Use something smoother than wax paper; like mylar next time.
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Old Jan 20, 2003, 02:11 AM
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Wayne's Gulp Pictures #11

Here is a picture of the wing taping. Note that I wrapped 2-inch bi-directional tape around the leading and trailing edge. It is available at Walmart and made by 3M. I ran a 1-inch strip of reinforced tape down the spar to help hide it. I don't think it improved the rigidity of the wing any; I could not bend it before the tape was applied. I also X-taped the tip top and bottom so that as I bash it and crash it, maybe the tips will not curl as much. You foamie guys know what I mean
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Old Jan 20, 2003, 02:23 AM
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Wayne's Gulp Pictures #12

And finally, here it is ready for it's first flight. The 8-balls are from Dan Borer (dborer@earthlink.net). He did a great job. I used Ultracote bright yellow, and Ultracote fake carbon fiber for the wing tips, tail and canopy. It looks very good in the sun.

And how does it fly you ask...

IT FLYS LIKE IT IS ON RAILS. IT REALLY DOES. It penetrates upwind very well and has excellent energy retention. I can stall it, but I have to make it stall. I have not been able to create a high-speed stall yet. At very slow speeds, it stalls straight ahead and recovers immediately. I did notice one odd thing though. When making an upwind run, the MH45 airfoil actually likes the "faster" air and appears to "accelerate" away from the other guys. I have looked at the airfoil with the airfoil comparison tool ( http://eiss.cnde.iastate.edu/calcs/frames.shtml ), and I understand the aerodynamics, but it is just a cool feature.


Thanks to Steve Drake (www.SteveDrake.com) for designing it.

Let me know your Gulp tips and tricks. I am going to order a Gulp SR soon.
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Old Jan 27, 2003, 07:55 PM
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Where can I find more info on the RAD style of control linkages (servo "arm" connectors, angle of torque rod, etc.)? Pros/cons of setup?

This guy looks soooo clean...
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Old Jan 27, 2003, 08:16 PM
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Rialto, CA
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Here is the link to the Rotary Drive system. http://www.proptwisters.org/rds2/index.html Lot of info on materials, pre-manufactured items, and theory. I bookmarked it, figuring one of these days I'll have to give it a try.

Jack
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Old Jan 27, 2003, 08:27 PM
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Nice Job , it looks like a Super Gryphon a.

I did not quite get your RAD servo thing though , are you just running the surface off of the output shaft?

Earl
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