I had hope to re-use the fins and air scoop on the rebuild. But, cutting them off the cone body made a big mess.
I could use the rear bulkhead. It was cut, removed and the edges sanded to clean it up for gluing again.
The picture on the left shows the angle of the rod if the launch lug were glued under a fin and along the angled cone body. I was always concerned about the off center thrust going up the launch rod. This might be the cause of some tail wagging Vulcan flights I've read about.
The picture to the right shows how I ended up gluing the lug, under the airscoop.
Looking from the rear shows the final position of the lug. (The picture makes it look like the lug is crooked, but it is straight.) The back of the lug was glued to the end of the tail cone. The top of the lug was glued to the inside of the air scoop. This is a better angle than just gluing it down the sides of the angled body.
It's not perfectly aligned with the internal motor mount tube, but it's at a better angle than the instructions would have you place it.
FOLLOWUP:
The rebuilt Vulcan was flown at the schoolyard on April 18 with a B6-2 engine.
There was no tail wagging during boost. As the model reached apogee there was a little wiggle, but not what I had read about in other reviews. Maybe the straighter lug glued closer to the body helped!
Excellent idea. My old Vulcan is still in flying shape. Surprising since it has spent the last few years in our garage. I'm going to give your idea a try tonight. Hoping for another B6-4 Field launch tomorrow, so with a little luck and decent weather.......
ReplyDeleteThanks Wallyum,
ReplyDeleteI think the straighter lug closer to the central tube helps.
But, in subsequent flights I've noticed a slight wiggle after the boost phase, when the model is slowing down, right before ejection.
Let me know if you see a difference in your flights.