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Last update, January 30, 2008
Main Boom Rigging
SailSetc parts (SE) and
all from
Midwest Model Yachting (MMY)
Part photos can be seen there.
Parts:
1 - Main boom kit 625 mm with fittings, MMY #100M
Comes with #160
attachment kit. Parts needed in this kit
listed here
individually for stocking reasons.
1 - Hook, MMY #178 ten pack
1 - Track slide and sheet hook, MMY #82S (boom
kit)
Track slides come with
cap screw length for what they do.
Sheet attach point, MMY #80L (boom kit)
Track slide for clew hook, (boom kit)
1 - 3 m coil of 3/64" wire for hooks, MMY #214
1 - Gooseneck/vang assembly, MMY #111.
See note below for other
parts in this assembly
1 - 18" length of 1/2" sleeve, MMY #14S
Screw stock.
Supplies:
Blue tape
Tools:
Metal saw blade
Drill and/or drill press with bits
Small file set
Metric ruler
5/64" ball hex tool
Triangle
Small hammer
Screwdrivers
SailSetc parts are finely machined, excellent
extruded aluminum parts and all well engineered for interchangeability. They are made
for several classes but much is adaptable to the EC12. The booms are used here
because they provided the controls needed, are easily installed and easy to
adjust. The rigging of these booms takes far less time than the arrow shaft
counterpart. Removing are installing the mainsail is very fast. However, all of this convenience
has a cost, of course.
Boom Construction
Look over the parts and the drawings that come
with them along with the photos here. It is straight forward with little
innovation for the EC12.
The boom arrives 625 mm long. Cut this to 555 mm
and clean the edges with a small file. Save the cutoff piece for your tool bag.
Cunningham (Downhaul)
In the boom kit is an IOM kit #160 with stuff for
the boom. Find the gooseneck insert (black) for the boom and slip it into one end of
your cutoff piece of boom. A hole will be drill into the flush end of the insert just below
where the gooseneck mount tang will go. A hole will be drilled in the tang just behind the hole for
the mast mount connection. These holes are to fashion a Cunningham guide for the mainsail
from a #178 hook. A line will tie at the tack grommet pass through the eyelet,
around the mast and back through the eyelet and connect to an adjuster on the
boom with a loop. This adjuster, and all on the boom, will be loosened and
tighten with a 5/64" ball hex tool shown here.
The use of the boom section to drill the hole
in the insert is to stand it vertical if using a drill press. A #55 bit was
used for the hole and about 1/4" deep. You will note there is a little
nail brad
in the slot to hold the insert while working with it. If you are building
more than one rig or stocking parts, drill them all while you are set up.
Take a #178 hook and straighten it like the
one in the photo. Remove the gooseneck tang from the gooseneck body.
Punch and drill a hole just aft of the mount screw for the hook. A #48 bit
was used so the hook will rotate through the hole and into the insert hole.
Assemble it as you see here and gloat over your nice work.
Place the assembly in the boom and tap the
tang
with a small hammer till it is fully inserted. Pilot drill a hole underneath
the boom for a shortened #2 sheet metal screw to secure the assembly to the boom.
Insert a boom track slide with a sheet hook (from the kit) and slide into
place near the gooseneck. This will be the Cunningham adjuster.
Main Sheetline
Install another boom track slide with a sheet
hook from your stock. This will point aft toward the sheetline guide and
will be the sheetline adjuster. The slide track with the
guide is called an adjustable sheet attachment point (Whew!). It comes in
the kit and will slide on from the aft end of the boom also. You will have
to press the guide tab into the track slide hole for it all to fit on the
boom. You will find all these parts have close tolerances and are secure
when installed. Because these are
adjustable we will not worry with where they go for now.
Clew Connection
There is a track slide and sheet hook in the
boom kit. However, for the EC12 and the foot round of the sail, the hook
will not reach the grommet without much sail dragging across the boom. You will need to make a longer
hook. In the parts list above
is #214 wire stock for this purpose and will be useful elsewhere. We will fashion a hook to attach the
clew of the mainsail later when the sail is on the spar. Park the slide with the
longer screw on the boom for now.
Gooseneck/Vang Mount
This major part assembly is called Gooseneck/kicking
strap at SE. That is for little boats and so it will be the vang on the
EC12.
Because the gooseneck body is not adjustable when
installed there is a question as to where it should be in relation to the
sail. The tack is first issue then the clew. So, let's wait on this a bit.
First install the boom to the mounting body and then
the vang to the base. Over lay this on a right triangle so that
you can adjust the vang to produce a right angle at the gooseneck to the
mast at the mount. Play with this till you understand where things are
loose and then make a mark on the boom where the far point of the vang hook
is. This mark should be considered with upward pressure on the boom and not while it is
drooping. Drill a #51 bit hole, insert the hook and reconnect it to the
vang. Okay, now that I told you how to do it the number for the hole is 183
mm from the gooseneck end and this includes the black insert.
In one of the photos here a solid spring vang
installed. This is an in stock vang that will be tested on this rig. The
photo is shown for those of you that prefer a more rigid vang with a hard
mount to the boom. The mount shown is Pekabe tang that was in stock. One
could be made from sheet aluminum. A 4-40 quick link from Sullivan was use
for the connection. The photo with the SE vang and the hook mount to the
boom is on the same boom so either one can be used during testing.
The SE vang was used in
five 2007 events including the NCR and worked fine. The SE vang (kicking
strap) will do the job just. However, the crafted solid vang is a preference
by some in the field for their tuning processes and for sheet vanging
techniques.
Parts Note: The mount is called Gooseneck
Body at SE. It can be ordered separately of the assembly from SE. You
would then need the gooseneck tang, #103t, in the SE catalog. These
parts are not stocked at MMY but you could inquire. To mention again
here, the SE catalog is free by
email request.
Cut a 98 mm length of 1/2" mast sleeve and
clean it up. Slide it on the mast for fit. This sleeve has several uses.
First it is a screw support for mounting the gooseneck body. Secondly, it supports
the lower mast so lower-lower shrouds are not needed.
For the moment leave all this as is till the
mainsail is installed. Then we will be able to mark location for the tack
grommet on
the sail and thereby determine the position of the body on the sleeve by
reference of the boom. Knowing this, the body will be attached to the
sleeve and mast with screws.
The parts for the boom are installed and it is
an assembly now. Later this will be rigged into the total Rig. The things
remaining are the hook for the clew of the sail and the final fastening of
the gooseneck body. Then we will have a hard number for this rig where that
top of the body flange will be and added to the chart above.
You are done here.
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