The VS was a little harder then the HS, but
like anything else, you have to work around all the little problems. My last bulkhead, the
812, was canted to the left, bowed inwards, and tilted back. This put the VS in a really
crooked position, and complicated things. I first started by marking centerlines on the
back of the 812, all the way down to the tailwheel mount, and marked a centerline on the
back of the VS rear spar. I clamped the VS into position, and using the mark on the back
of the spar, and the mark on the tailwheel mount, I got the rear spar on center at the
bottom.
I then got the VS vertical by hanging a
plumb line down through the hinges. I double checked the vertical position by measuring
from the tip of each side of the HS to the tip of the VS. Make sure you measure to the
rear of the VS, since the angle relative to the centerline of the fuse is not set yet.
Once everything is in position, verify that it is straight by eyeballing it from a
distance. Make sure you check that your hingeline is still straight. Use a 6' level or
other appropriate straight edge, and lean it up against the top edge of your hinges. If
they all touch the straightedge, then the line is straight. Verify this by using a
tightwire through the hinges as per the manual. When everything looks good, drill the bolt
attach points at the bottom and at the 812B angle. Be careful to catch the edge distance
on the 1/4" bolts that go through to top of the tailwheel weldment. I had to drop my
VS down a little lower by filing 1/8" off the bottom of the rear spar, and 1/16"
off the lower edge of the skin at the front of the VS. This gave me the edge distance
required (Tom at Vans told me to get 1/8" or more, since proper edge distance is not
possible here). I later found out that there is a much easier way. If you can't catch the
weldment with the top bolts, simply add two more bolts lower on the VS. There is a
dimension on the plans that I missed, measured from the lower hinge bracket on the VS to
the top of the 812B angle. Make sure you make this measurement.
Now it's time to set the angle relative to
the centerline of the fuselage. First, find the center of the front edge of the VS and
mark it. I did this by wrapping a piece of string from the center of a rivet on one side,
to the center of the same rivet on the other side, marking the position of both rivets on
the string, then laying it out on a table and marking the center between both points. Now,
tape the string back up, with the outer marks on the 2 rivets you used. The center mark
will designate the center of the VS. Transfer the mark. The center of the turtledeck was
determined by measuring from the tip of the HS on each side until a center point was
found. I verified it by eyeballing down the fuse and lining up my forward centerline with
it. The string trick could also be used on the turtledeck. My VS required about a .063
shim on the right side to get it centered.
With everything centered and lined up, it's now time to attach the front
spar. The first thing I did was cut about 3/4" off the end of the front spar, so it matched up with the top of the HS front spar. With my 681 attach plate
clamped to the front of the VS front spar, I still had about 3/16" to go to make it
meet the HS front spar. I made this up by putting a 1/16" shim between the VS spar
and the 681 plate, and a 1/8" shim behind the HS front spar. I did it this way
because it's easier to rivet thinner materials. Riveting a 1/8" plate to the VS front
spar seemed a little more challenging then just bolting it to the HS front spar. I drilled
the 4 attach holes all wrong, and had some hassle getting them through. I took the HS off
the fuse, and pilot drilled through the 810 and 814 to make sure the holes were perfectly
centered. I was quite proud of myself for thinking ahead, and thought I had a great idea
until I realized that my angle drill would not fit between the bulkhead and the HS spar,
so I couldn't use the pilot holes I just drilled to finish the job. I ended up finding a
very short #40 bit, and drilling best I could through the center of my #30 pilot holes,
then finishing up from the back side. It wasn't all that bad, but just a heads up to make
sure you can get to those holes if you're gonna drill them from the front of the HS.
The VS was a little harder then the HS, but
like anything else, you have to work around all the little problems. My last bulkhead, the
812, was canted to the left, bowed inwards, and tilted back. This put the VS in a really
crooked position, and complicated things. I first started by marking centerlines on the
back of the 812, all the way down to the tailwheel mount, and marked a centerline on the
back of the VS rear spar. I clamped the VS into position, and using the mark on the back
of the spar, and the mark on the tailwheel mount, I got the rear spar on center at the
bottom. 
I then got the VS vertical by hanging a
plumb line down through the hinges. I double checked the vertical position by measuring
from the tip of each side of the HS to the tip of the VS. Make sure you measure to the
rear of the VS, since the angle relative to the centerline of the fuse is not set yet.
Once everything is in position, verify that it is straight by eyeballing it from a
distance. Make sure you check that your hingeline is still straight. Use a 6' level or
other appropriate straight edge, and lean it up against the top edge of your hinges. If
they all touch the straightedge, then the line is straight. Verify this by using a
tightwire through the hinges as per the manual. When everything looks good, drill the bolt
attach points at the bottom and at the 812B angle. Be careful to catch the edge distance
on the 1/4" bolts that go through to top of the tailwheel weldment. I had to drop my
VS down a little lower by filing 1/8" off the bottom of the rear spar, and 1/16"
off the lower edge of the skin at the front of the VS. This gave me the edge distance
required (Tom at Vans told me to get 1/8" or more, since proper edge distance is not
possible here). I later found out that there is a much easier way. If you can't catch the
weldment with the top bolts, simply add two more bolts lower on the VS. There is a
dimension on the plans that I missed, measured from the lower hinge bracket on the VS to
the top of the 812B angle. Make sure you make this measurement.
Now it's time to set the angle relative to
the centerline of the fuselage. First, find the center of the front edge of the VS and
mark it. I did this by wrapping a piece of string from the center of a rivet on one side,
to the center of the same rivet on the other side, marking the position of both rivets on
the string, then laying it out on a table and marking the center between both points. Now,
tape the string back up, with the outer marks on the 2 rivets you used. The center mark
will designate the center of the VS. Transfer the mark. The center of the turtledeck was
determined by measuring from the tip of the HS on each side until a center point was
found. I verified it by eyeballing down the fuse and lining up my forward centerline with
it. The string trick could also be used on the turtledeck. My VS required about a .063
shim on the right side to get it centered.
matched up with the top of the HS front spar. With my 681 attach plate
clamped to the front of the VS front spar, I still had about 3/16" to go to make it
meet the HS front spar. I made this up by putting a 1/16" shim between the VS spar
and the 681 plate, and a 1/8" shim behind the HS front spar. I did it this way
because it's easier to rivet thinner materials. Riveting a 1/8" plate to the VS front
spar seemed a little more challenging then just bolting it to the HS front spar. I drilled
the 4 attach holes all wrong, and had some hassle getting them through. I took the HS off
the fuse, and pilot drilled through the 810 and 814 to make sure the holes were perfectly
centered. I was quite proud of myself for thinking ahead, and thought I had a great idea
until I realized that my angle drill would not fit between the bulkhead and the HS spar,
so I couldn't use the pilot holes I just drilled to finish the job. I ended up finding a
very short #40 bit, and drilling best I could through the center of my #30 pilot holes,
then finishing up from the back side. It wasn't all that bad, but just a heads up to make
sure you can get to those holes if you're gonna drill them from the front of the HS.
