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Archive for December, 2012
Posted by burkefj | Dec 25, 2012 @ 09:46 PM | 12,010 Views
Thanks to my lovely family who got me enough foam, and electronics to make another rocket glider. They also gave me a half a day repreive yesterday and today to work on it. I've been wanting to try a spaceship one , but have been worried about CG, twisting and stiffness of the tail booms. It came out ok, I wound up having to put some parallel stiffeners on the bottom of the wing to help prevent twist.

I couldn't find a decent 3-view that I liked or thought was right, so I just did this freehand from a book I have from pictures and relative sizing. I think it captures the look if not perfect scale. The full flying control surface placement was dictated by the fact that I wanted to put the pivot rod accross the fuse and tie it in just in front of the rocket motor mount. This helps reduce the twist of the tail booms and worked well, and actually came close to where they are supposed to be. Since I was doing a cruciform structure, I had to move the wing placement to the middle of the fuse instead of the upper portion, but I don't think it makes that big of a difference in look. I did not add the later stub strake fins in front of the control surfaces yet till I fly it and see how it does without them. Due to the lack of stiffness of the booms, I glued in carbon tubes in each one and laminated a 3mm cover over the tube, that made them very stiff. The wing still had some twist so I used two carbon tube spars as well.

I mounted the servos as far forward as I could to...Continue Reading
Posted by burkefj | Dec 20, 2012 @ 11:47 PM | 12,467 Views
I decided I wanted to try doing one of the proposed Delta wing configurations for the X-15-3 plane, I chose the one normally modeled with the diamond wingtips...I made it simply by taking my X-15 plans, stretching the fuse the scale amount(about 10 inches) and changing the top view to a delta with wingtips. I added some 3mm covers on the sides of the fuse to sort of give it a look like the fairings had. It gives it a bit more body. It's all completed except for painting now, and the fairings added quite a bit of stiffness to the body. It came out at 55.5" long and about 21" wing span which is slightly oversized just for wing loading. Weight is right at 13 oz rtf, but without paint, so assume about an ounce more finished.

Update 12/21/12 Since the world didn't end yet, i had enough time to paint the Delta X-15 and do the markings. Came right out at exactly 14 oz rtf. Pictures show it next to the X-15-2

Update 12/27 Good maiden this morning. CG and throws were spot on as was glide trim, very nice!
Here is the cg calculator I used:


Flight video:
X-15-3 Delta Configuration RC Rocket boosted glider (0 min 41 sec)

Here's a scaled down version with CG location