The body tube was marked for the fin positions earlier in Step 3.
The fin alignment slots were too tight on the fins. It took a little sanding with 400 grit to widen the slots.
GOTCHA: The instructions recommend tacking the fins on first with medium Super Glue. I wouldn't recommend this, Super Glue seals the surfaces and effects the adhesion of the glue fillets that follow.
Super Glues become brittle over time and those joints could fail. Super Glues are good for strengthening the ends of body tubes and stiffening up card stock shrouds, not for basic model rocket construction.
TIP: Glue on one fin before using the fin alignment tool. Let the fin dry, then slide on the alignment tool over the glued on fin.
This will steady the alignment tool and makes the second and third fin much easier to place.
The same method is used for the smaller, forward fins. Glue one on, slide on the tool and follow with the second and third fins.
Chris, does gluing on the upper smaller fin work better with the supplied tool or by attaching the bottom fins then using Popsicle sticks and cloth pins to align the fins - I've seen you do it that way in the past?
ReplyDeleteAlso, Semroc provided you three fin alignment tools, you thought you may use two, but did you just use one of them?
Hi Scott,
DeleteThe model is too small to use the Popsicle sticks and clothes pins. I used a pencil line down the body and visual alignment to get the two sets of three fins in line.
Three tools are supplied but I only used one.