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<DIV><FONT face=Arial size=2>Keith,</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>On the square for lining up the rudder
post. </FONT></DIV>
<DIV><FONT face=Arial size=2>If you have perpendicular lines layed out on your
table you just lay the square on the line that is perpendicular to the
fuse. This way you can tilt the square forward or back(in the case of a
canted rudder post) and still have a square post. Of course a scribed line
in the center of he post is needed. I use the Great Plains center scribe
for this as it will make a center line that will conform to a tapering
hinge area.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Wayne G.</FONT></DIV>
<BLOCKQUOTE dir=ltr
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=tkeithb@comcast.net href="mailto:tkeithb@comcast.net">Keith Black</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=discussion@nsrca.org
href="mailto:discussion@nsrca.org">discussion@nsrca.org</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Monday, October 25, 2004 1:24
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: Building Lasers</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial size=2> think lasers are hugely helpful in some
cases. I find them particularly helpful when trying to draw a straight line on
an unlevel surface, or a particularly large area such as a line across an
entire room. An example of an unlevel surface for modeling would be drawing a
straight line right down the center top of a fuselage from the top of the fin
to the front of the nose, or when drawing a line down the side of the plane.
In both of these cases you're working with a curved surface and the laser will
follow the contour (be sure it's lined up correctly).</FONT>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>The down side to lasers I've found are: One, the
laser I have has a relatively thick beam as compared to the accuracies we
need, between 1/16th" and 1/8th" depending on distance. It's harder to be
exact that you would think. Second is that you can sometimes be misled when
the beam goes across surfaces that curve further away or closer to the source
of the beam. This will distort the beam unless it's exactly even with the
location you wish to draw the line. </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT><FONT face=Arial
size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>After messing with lasers in the past to try and
do alignment I feel the best way to align the stab is to have a level table,
put a scribe line on the rudder post and use a square to make sure the fin is
perfectly perpendicular to the table. Then when mounting the stab use a height
gage to make sure the stab is exactly the same height from the table at all
points (front corners, back corners, center fronts, center backs). This will
yield a perfectly aligned stab, height wise at least. You also need to make
sure the stab tips are aligned equal distance from some center point in
the front of the plane (I won't go into this, the best bet is to buy Bob
Noll's tapes).</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>What I sometimes find difficult in this process
is eyeballing the square and the rudder post to make sure indeed the fin is
exactly 90 degrees to the table. In some cases you can butt the square right
up to the rudder post, but in other cases you can't do this, or the rudder
post is at an angle. This is when my eyes play tricks with me since the square
isn't up against the scribe line. In this case a laser may be useful, however
remember that the laser must be perfectly lined up behind the rudder post
(side to side) or the angle of the laser combined with an angled rudder
post will cause the line not to be true.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>For the alignment of the main wing it's necessary
to use some type of measuring gadget, like Bob Noll describes, to make sure
the wing tips are equal distance from the stab tips, but when it comes to the
wing tips being lined up height wise to the stab tips I think this can be done
more accurately using the eyeball than with any measuring tool (at least the
tools I have). If you stand ten of fifteen feet in front of the plane and
position yourself exactly in the middle of the fuse you can raise and lower
your head and see if the wings are even with the stab. Also do this from
behind the plane. This can be done with incredibly accuracy. In fact, I've
done it using measuring tools and afterwards found that my tools couldn't get
it as accurate as my eyeball. And since you've made sure the stab is correct
it's a good measure for the primary wing (I set my stab first). </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I've used the a laser to confirm my eyeball
measurements for the wings being level with the stab, but due to the thickness
of the beam, and the fuzziness around the edge of the beam, it's tough to get
it to the accuracy of my eyes.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>BTW, I didn't pioneer these methods. It's thanks
to other modelers that have shared their approaches to doing things that I
know this. Out of all the different methods that have been suggested to me
these are the ones that I find work the best.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>For anyone who's new to building, or just wants
more tools for their building arsenal, I strongly recommend Bob Noll's tapes.
The one for alignment is called "Perfect Airframe Alignment". You can order
them at 610-746-0106. He has a set of four tapes that go through many of the
difficult parts of building a pattern plane.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Keith
Black</FONT></DIV></DIV></BLOCKQUOTE></BODY></HTML>