|Jan 04, 2012, 02:49 PM|
Bomarc Upscale rocket glider
Started this this morning, an upscale of my bomarc pusher or rocket boosted glider, this will be for 29mm rocket motors.
The nose looks a bit short since the top view is not on the centerline of the fuse, due to the high mounted wing, the side view nose will be another foot longer. Length will be about 80 inches, and wingspan 30"
Update 1/08/2012 Finished the ramjet pods, with carbon rods installed to go through the fuse and styrene skid reinforcement. I wanted to keep the air flow through the ramjet pods to reduce drag, so I left the front tapered portion profile and did an xform support for a thin bt101 tube for the rear portion, and wrapped them with chrome monokote. I think it will give the right look but still be fairly light. The body tubes added almost 4 ounces of weight.
I made a 12" spruce bar to mount the rail buttons on and installed them into the fuse with carbon rods to glue into the fuse for support. I then laminated styrene sheet on both sides to support it and to act as support for the ramjet mounting rods to go through. It seems pretty stiff. Ready now to slice the top fuse and slot and tab it and attach to the top view.
Update 1/09/2012, finished it except for the tan nose. Total weight with balast and motor rtf is 39 ounces. Looks like it will be a candidate for G-33's.
Update 1/11/2012 Test flight success! G-40 was a bit hard, the G-33 was a better boost, glide was pretty good, it was windy and the model wanted to bind on the rail due to being blown side to side. All in all, a well mannered glider.
To fix the problem of binding on the rail, I glued a 1.5" double thick strip of styrene on the bottom of the rail button mount and then mounted the rail buttons on that. The wide plastic gives enough bearing surface to keep the model from twisting side to side and reduced the binding to a non issue.
Update 1/15/2012: I formed new ramjet tubes from 3mm depron covered in chrome monokote. It saved 2 ounces of weight from the rear end compared to the rocket tubes, and I was able to remove 1.25 ounces from the nose, so about a 10% reduction in weight.
Update 9/31/2012: Had two great launches this weekend on the last two G-33's. I my effort to find a replacment that is actually still made, I think I can use the Aerotech G-38 FJ which has slightly higher thrust but not too much more, and the loaded weight is 25 grams less which means I can pull another 25 grams out of the nose so I can save another ounce and a half.
The depron tubes with chrome monokote held up well on boost and landing even though we were flying on a hard plowed field..
Here's the video
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