HERE
Things get vague in Step 6 of the old Estes instructions.
They don't specify how far up to glue the "flip-flap".
(Really, they called it a flip-flap!)
You've got to allow for the friction tab and the drawing does show the root edge hanging over the body tube end.
I set the tab on the fin side and guessed!
The instructions don't say where to apply the glue. I have to wonder how many of these were built with the root edge of the flap glued to the body tube.
On the right side of the picture I've folded the flap and will only apply glue to the root edge above the fold line.
More vague instructions:
The launch lug is trimmed and glued to the line between the flip flop fins. How high? Who knows!
I guessed after looking at the pictures and set it 1" from the end of the body tube.
With the flap taped down the main fins are glued on their pencil lines.
Because the fins are large -
You are best off using the double glue method and not much glue.
Get the large fins to tack in place, be sure they are straight then add white glue fillets.
The width of the tube marking guide is used to set the rudders.
Instead of holding the marking guide and gluing the fins on, I decided to use the side of the marking guide to draw a gluing line with a pencil.
For an even better alignment, the back of the marking guide was cut off at the same angle as the fold of the fin.
Actually, instructions call it "fin-flap" assembly, not "flip-flap".
ReplyDeleteNoticed that you matched up the flap root edge with the fin and left that portion of the edge square. If I'm not mistaken, there was supposed to be a slight gap between the flap root edge and the body tube (if you take the parts templates from the pattern sheet and lay them out, you'll find out that the flap is slightly shorter than the fin. Also the instructions show the root edge of the flap portion to be rounded rather than left square). Although having the flap root edge seating tightly against the body tube might give a cleaner appearance, you'll probably run the risk of the flap binding against the body tube - especially after primer and paint.
As far as the positioning of the fin-flap assembly -- I'd interpreted the general layout illustration to indicate that the hold-down tabs should be attached to the flap near the "corner" at the root edge of the flap (where it flares out), and that the forward edge of these hold-down tabs would need to be set back far enough to clear the rear edge of the body tube, but not so far back that the hold-down tabs would protrude below the rear edge of the engine when it is inserted. This pretty much ends up determining the location of the fin-flap assemblies.
Anonymous -
ReplyDeleteYou are right! I did a blog post trying to answer what I didn't do..
http://modelrocketbuilding.blogspot.com/2013/12/gyroc-part-7-post-corrections.html