Double Sets of Fins - Need Advice

Double Sets of Fins - Need Advice

Post by LisaAS » Sat, 16 Sep 2000 12:38:59



I'm getting ready to put two sets of three fins on a single body tube.  Are
there any special tips or tricks in lining the top and bottom fins together? Do
most people put on the top set then line up the bottom set, or line a top and
bottom up, then rotate the tube 120d and line up another top and bottom.

TIA,
Lisa

 
 
 

Double Sets of Fins - Need Advice

Post by Bryan Chuc » Sat, 16 Sep 2000 14:55:24


Lisa,

How close are your fins?

If they're within a few inches, here's a trick that I used for my recent
build of a PML Endeavour. I did two fins at a time with mid-cure epoxy, the
forward and rearward. To help line them up, I used a Chip Clips from the
local Safeway grocery store. Presto! Straight fins! This worked great for
me.

If your fins are surface mount, perhaps attach one fin and let it dry. Then
add the second, rearward fin and attach the clip to assist you in getting it
straightened up.

If the fins are farther than a few inches from each other, you might
consider using two dowels, body tubes, etc., on each side of the fins to
help you roll them into alignment. I've applied this technique to launch
lugs to get 'em lined up.

Hope this helps.

Bryan


Quote:

> I'm getting ready to put two sets of three fins on a single body tube.
Are
> there any special tips or tricks in lining the top and bottom fins
together? Do
> most people put on the top set then line up the bottom set, or line a top
and
> bottom up, then rotate the tube 120d and line up another top and bottom.

> TIA,
> Lisa


 
 
 

Double Sets of Fins - Need Advice

Post by baDB » Sun, 17 Sep 2000 13:05:54


Lisa,

Put a marks on the tube 120 deg apart.  Then (if a small diameter
tube) use the door stop on any door frame to draw three lines the
entire length of the tube.  glue your fins on these lines.  If a large
diameter tube, a piece of angle iron (or aluminum) works great.

Bob


Quote:

>I'm getting ready to put two sets of three fins on a single body tube.  Are
>there any special tips or tricks in lining the top and bottom fins together? Do
>most people put on the top set then line up the bottom set, or line a top and
>bottom up, then rotate the tube 120d and line up another top and bottom.

>TIA,
>Lisa

 
 
 

Double Sets of Fins - Need Advice

Post by Mark Simpso » Mon, 18 Sep 2000 15:01:44


For bigger rockets, I attach the biggest fins first and make sure that they're on
straight. After the glue dries, I take two long metal angles and 2 c-clamps and
clamp the channels to the fin.  I, then, slide the smaller fin into the groove
created by the metal angles and voila! perfectly aligned  fins.

Mark Simpson
NAR 71503 Level II

Quote:

> I'm getting ready to put two sets of three fins on a single body tube.  Are
> there any special tips or tricks in lining the top and bottom fins together? Do
> most people put on the top set then line up the bottom set, or line a top and
> bottom up, then rotate the tube 120d and line up another top and bottom.

> TIA,
> Lisa