J.A.E. Racing JAE12G4 Hybrid Instruction Manual

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Z I P P M A N U F A C T U R I N G
JAE12G4
Hybrid
A Zippkits R/C Boat
Building Instructions
2014 JMP Hobby Group LLC –Indiana USA
www.zippkits.com
Toll Free (866) 922-ZIPP

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The JAE series was designed and developed as a result of a joint venture between IMPBA Hall
of Fame member Rod Geraghty, David Hall, Ron Zaker Jr. & Martin Truex Jr.
The main difference between this hull and all the others is the use of sharp edges on the bottom
of the sponsons and tub, as opposed to curved surfaces. This helps break any surface tension
of the water and makes for a faster boat.
This design approach has been built, developed and tested a great deal.
The 12G4 Hybrid kit is a light version of our popular JAE 12G2 kit. About 25% lighter…
This reduction in weight is substantially faster, and is still robust enough for everyday heat
racing. The JAE 12G holds several world speed records.
The Hybrid refers to a mix of all of the JAE 12G versions. Light, but not too light. Strong, but not
too heavy. Easier to build too.
In addition to a marine engine, you can use any air cooled 12, 15, 18, 20 (small block) car or
truggy engine, with excellent results.
The kit is not hard to assemble, as all of the hard stuff has been done for you.
That is no excuse to do a poor job with assembly. The better you build this boat, the better it will
run. Often the difference between an excellent building job and a poor one is a simple sanding
block.
A note about overhangs:
This boat is designed to shear water and prevent any capillary action of water. To do this the
tub, ski and sponsons have sharp edges and rear overhangs. These shear the water off and
must be left in place and not rounded in any way.
Take the time to read this entire manual, so that you are familiar with all the buildings steps and
their proper order. Take your time; make sure you understand everything before you do it and
you will be rewarded with an impressive running hull…
Note that the pictures in this manual may be of a different boat to better illustrate a point.
This boat is built exactly like the 12G2, so we used some of the same pictures.
This kit is not a toy. Although R/C boating is a fun and rewarding hobby, it can be dangerous
if not done with common sense and safety in mind. Just about anyone should be able to
build this kit, but it should not be operated by children without close adult supervision.
The manufacturer assumes no liability for damages or other loss in theuse of this product, as
we have no control over the construction or end use of this product.

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Tools and supplies needed to build
Sanding blocks with 80 and 150 grit paper
Drill with bits (1/16, 3/32, 5/32, ¼ inch)
Square
Flat file
FLAT Workbench
1/2 ounce Medium CA glue and accelerator
Good quality 5 or 30 minute epoxy
Epoxy finishing resin
Spring clamps, paper clamps, c clamps, etc.
Razor blade or X-Acto knife
Masking tape
Waxed paper
Wood filler
Primer
Paint

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Additional items needed to complete
.10-.20 air or water cooled Nitro engine
.150 Collet and flywheel for engine (Zipp 3541 for 5mm)
Starting belt if needed (Zipp 3548)
.150x16 inch cable w/welded 3/16 stub shaft (Zipp 3475)
Header to fit engine
Tuned pipe
2 channel surface radio with 2 servos (Hitec HS-225MG and Zipp 5001 recommended)
Throttle and rudder pushrods (.055 Size) ( Included in Zipp 3606 Set)
2 pushrod seals (Zipp 3404)
4 ounce Fuel Tank (Sullivan SS-4) (Zipp 3473)
Z21 Strut (Zipp 3494)
.187 drive dog (Zipp 3485)
440 prop (Zipp 4007)
10-32 Prop nuts (Zipp 3489)
Engine Mounts ( Zipp 3554)
Cable grease
Rudder (Zipp 3477)
12 inch length of 1/4 brass tubing (Zipp 3474)
Note that all items need to complete your 12G4 are available as a complete set.
Order part number 3606 Ultimate Hardware Set
Let’s identify the parts so that we can easily find them when needed. Mark the parts that are
inside other parts.

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1/32 plywood parts:
1/16 plywood parts
1/8 plywood
parts

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Miscellaneous parts
Foam parts
Left Sponson Foam Right Sponson Foam Nose Foam
Do an inventory of all the parts, to be sure that everything is there. If anything is missing or
damaged, contact us as soon as possible, so that we can get replacements to you quickly.

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Tub Jig
We recommend that you make a jig for the tub.
This can be as simple as two straight pieces of ½ to ¾ inch thick wood.
It can be as elaborate as 1/16 by 1-1/2 inch aluminum angle with adjustment slots for different
tub widths.
We mounted some aluminum angle to a piece of ¾ inch MDF.
Either way, you need something to clamp the tub sides to.
Every critical component on this hull depends on a straight, square tub.
Do whatever it takes to get it done correctly.
Tub Jig

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Tub sides marked before assembly.
Bulkheads in place. Note position of holes.
Ready for the bottom.
Tub
Let’s build the tub.
First, mark the insides of the tub right and
left. The sponson boom hole is toward the
bottom of the tub side.
Lay these out in a mirror fashion.
Make these marks in the front portion of the
sides, where it won’t be seen later.
Check the fit of the bulkheads in the right
tub side.
Once you are happy with the fit of the
bulkheads in the tub side, glue them in with
CA. Use the square provided in the kit to
ensure each bulkhead is perfectly square.
Glue BH-2 so that the pushrod hole is to the
right.
Glue the transom in place so that the 2
small holes are on the right.
Assemble the tub sides on a flat surface
Check the fit of the bulkheads in the left tub
side. If all is well, glue the bulkheads in
place one at a time, using the square from
the kit.

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Holes in bulkheads must be as shown…
Tub in jig.
Transom doubler clamped in place.
Flip the tub over and lightly sand the
bottom.
Now is the time to use your tub jig. If you
don’t have the ability to make an aluminum
jig, use a pair of thick wooden sticks.
Make sure they are straight. Leave these
clamped to the sides while gluing the aft
bottom in place.
Glue the 1/8 transom doubler in place.
Make sure it is flush with the top of the tub.
Put a layer of waxed paper over the jig.
Put the tub aft bottom in the jig and set the
tub onto it.
The bottom sheet should be flush with the
front of bulkhead 1.
Make sure that the aft bottom has about a
1/16 inch overhang at the rear.

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Transom braces in place against the transom doubler.
1/8x1/8 square basswood strips in place.
Tub sub nose being glued in place. Tub extends just past jig.
Set the 1/8 ply transom braces in place
against the transom.
Measure and cut the 1/8x1/8 basswood to
fit between the bulkheads.
These get glued with the bottom and
reinforce the side to bottom joint.
You should end up with 4 pieces.
If all is well, glue the aft bottom in place with
epoxy.
Also glue the transom braces and 1/8
basswood in place.
Fully clamp the jig sides to the jig.
Glue the tub sub nose to the very front of
the tub. This supports the nose for
sheeting, and provides a solid base for the
tub nose block.
When the tub bottom has cured, let’s move
on to boom tube alignment.
This is probably the most critical step in the
assembly, so take all the time needed to
get this right.
Remove the tub from the jig.

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Tub sleeves sanded, ready to glue in.
Tub sleeves, doublers and booms in place.
Measuring boom tube distance above flat bench.
Grab the two brass boom tube sleeves, and
use 80 grit paper to rough the last ¼ inch or
so of each end.
Put the rear tube doublers in place and slip
a boom tube sleeve and carbon boom tube
through the tub and doublers.
Measure the carbon tube on each side of
the tub, and center it. Make some pencil
marks on the tube, on the outsides of the
tub so that you can quickly center the tube
later.
Do the same for the forward boom tube and
doublers.
The forward boom tube doublers line up
with the forward boom tube holes. They
only align correctly one way, so be sure that
the orientation is correct before you mix any
glue.
Weight the tub so that it is flat on the bench.
Clamp the doublers in place without glue
and measure the ends of the tubes.
Both sides of the tubes should be the same
distance from the bench.
If not, loosen the clamps and adjust the
doublers until they are.
If the doublers or holes now have to be
sanded to fit, you must sand them and
repeat the measuring process.
This is a critical step in the assembly, and if
done incorrectly, your hull will never handle
properly.
When you are happy with the height of the
tubes above the bench, check to see that
the tubes are square front to back with the
boom square provided in the kit.
When you have checked and double
checked that the boom tubes are straight
and square to the world, remove the
clamps, but leave everything in place.

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Tub sleeves sanded flush with tub side.
Lid frame in place on deck bottom. Skinny end forward.
Lid frame showing “lip” for radio box lid.
Mix up some 30 minute epoxy, and coat the
doublers where they will be in contact with
the tub sides and bottom.
Align the tubes and clamp in place.
Quickly check your measurements and
square several times, and make any tiny
adjustments before the epoxy starts to cure.
Use any excess epoxy to build a small fillet
around the brass sleeves and doublers.
Clamp in place.
Set aside for at least 3 hours.
Be sure everything is perfect before you
walk away…
Once everything has cured, sand the brass
tub sleeves flush with the tub sides.
Prepare the tub top by installing the radio
box “lip”. This 1/32 ply lid frame goes inside
of the radio box opening to provide a lip all
the way around for the radio box lid.
The frame goes with the skinny end
forward.
Use a teeny glue bead so that you don’t get
glue blobs in the lip area.
Flip the top over so that you can be certain
that the lip is centered, all the way around,
on the tub top.
Be sure that the skinny end goes forward.
If you don’t, the top won’t fit the tub.
Glue this in place with CA.

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Foam nose block being test fit.
This is what makes a JAE a JAE… Sponsons are similar.
Forward bottom sheet in place. Leave back end square.
Check the fit of the foam nose block. If all is
well, glue the foam nose block in place with
epoxy or poly glue. Allow to cure.
Sand the foam flush with the tub sides.
Be careful not to sand the tub sides too
much.
Foam sanded to match tub sides. Note angle sanded on
aft sheeting.
This foam is needed for floatation, in case
you shear off both sponsons…
Glue the forward bottom in place with
epoxy. Be sure to sand the angle into the
aft sheet so that it matches the tub sides.
The forward bottom sheet should cover the
bevel on the aft sheeting and be left square.
Do not sand the rear of this sheet; it needs
to have a sharp edge for the water to shear
off.
See drawing.

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Shaft tube with “S” bends. Available pre-bent.
Take your time with the shaft tub. Leave a lot at the rear.
Looking good…
Install your engine mounts, then screw the
engine in place on the mounts. We
recommend Zipp Super Mounts.
With the engine in place, we can move on
to the shaft tube.
This is another area that will need to be
done perfectly for a good running hull.
Bending the shaft tube is a piece of cake, if
you know the secret.
The ¼ inch brass tubing needs to be
annealed.
This will make it easy to bend by hand,
without kinks.
To anneal the tube, simply heat it with any
propane torch, until it changes color.
You will see the brass color change to a
sort of blue. It only takes a couple of
seconds, so watch for it.
When you see the tubing change color,
move the flame slowly down the tube until
the whole thing is done.
Put a screwdriver in one end of the tubing
to hold it while you heat it.
Try not to anneal the last inch on each end.
When the tubing has cooled off we will be
bending it into an “S” shape.
Why an “S” shape?
Tests have proven that a tube with two
bends has less drag than a tube with one.
The reason is that two bends support the
flex cable better, reducing cable whip, and
drag.
Remove the engine.
Put the shaft tube through the hole in the
rear bulkhead, and the hole in the tub
bottom.
Let the tube stick through bulkhead by
about an inch.
Mark the shaft tube here for reference.
Now study the side view of the shaft tube,
and carefully and slowly bend the “S” shape
into the tube.

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Shaft tube should line up with engine collet.
Ski parts ready for assembly.
Ski sides glued to bottom about 1/8 inch from rear.
Try to make sure that the tube sticks
through the bulkhead the proper amount,
and the rear of the tube is about ¼ inch
from the tub bottom.
Take your time, and go a little at a time.
If you try to rush it, and kink the tube, you
will have to start over with a new tube.
When you finish, you should have a nice
“S” tube that starts about 3/8 inch behind
the engine collet, and continues past the
rear of the boat (we will trim it later).
If all else fails, contact us for a pre-bent
shaft tube…
Don’t glue the shaft tube in place until we
check it with the ski in place.
Ski
Assemble the 3 parts of the ski using epoxy
or CA.
Glue the ski bottom onto the sides. The rear
should be about 1/8 inch longer, and let the
front overhang. Clamp or tape this
assembly until cured.

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Ski sanded to bevel in rear.
Note long bevel sanded in front of ski.
Servo mount parts.
Sand a sharp bevel on the front and rear of
the ski bottom sheet, so that it blends into
the tub bottom. Do not glue the ski to the
tub yet.
You can seal the inside of the ski at this
point. Use epoxy finishing resin.
Servos
Assemble the servo tray. This is made from
the servo mount base, straps and the four
plywood blocks.
This tray will fit the Hitec HS-225MG rudder
servo and the Zipp 5001 throttle servo.
Use epoxy or medium CA to build the tray.

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Dual servo mount assembled.
Use servo screws to retain. Don’t over tighten…
Mount starts 3/8 inch from transom. Touches side.
Check the fit of the servo in the tray. You
will have to cut a recess for the servo wire
in one block.
Make sure that the servo is a tiny bit taller
that the mount, otherwise, the strap won’t
tighten the servo.
Use servo screws (not supplied) to attach
the straps.
Be sure to drill 1/16 pilot holes so that the
mount doesn’t split.
Measure 3/8 inch forward of the transom
and make a mark.
The servo tray should go to this line, and
contact the 1/8 bass on the left side.
Glue the servo tray to the tub floor. Don’t
get any glue on the servo or wire.
Allow to cure.
Use a ¼ inch bit and drill the pushrod hole
in the transom. This hole is already drilled
in the transom, you just need to finish
drilling thru the doubler.
You can hold a block of wood tight against
the inside of the tub to prevent the drill from
splintering the wood on the inside.
Be careful and don’t drill into your fingers.
You might as well drill the other holes now.
The small holes for the rudder are 1/16 and
the holes for the strut are 5/32.

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Rudder and strut bracket mounted to transom.
Rudder pushrod in place. Use inner hole at servo.
Pushrods. Note single bend in throttle pushrod.
Go ahead and mount the rudder and strut
bracket to the transom.
The pushrods are next.
We like to use .055 music wire for pushrods
with a “Z” bend at the servo.
The rudder pushrod is 4-1/4 inches long
and the throttle is 9-1/4.
Make a “Z” bend in one end of each
pushrod. This will be the servo end.
Put the rudder pushrod in the servo arm as
close to the center as possible (all the way
in).
This gives reduced throw needed for the
rudder.
The rudder pushrod simply goes straight to
the rudder arm. You will need to move the
rudder pushrod connector in one hole.
Put the throttle pushrod about 5/8 inch from
servo center, or almost all the way out.
The throttle pushrod needs one bend near
the carb. Make sure the bend is forward of
the bulkhead by an inch or so.
Adjust the bend until it meets the carb arm.
Install an EZ connector in the carb arm and
secure with the metal washer. Open up the
hole in the carb arm very slightly so that the
EZ connector can spin freely, but not
wobble.
Secure the pushrod with a set screw
instead of the screw in the set.
We will do final adjustments to the throttle
and rudder later.
Remove the servos and pushrods.

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Throttle pushrod in place.
Getting tub ready to seal interior.
First coat of sealer done. One more to go.
Remove everything from the boat in
preparation for sealing.
Use epoxy finishing resin (or West Systems
epoxy) to seal the inside of the tub. Be sure
to seal around the boom tube sleeves,
pushrod holes and all around the servo
mounts.
Use any excess epoxy to seal the
underside of the deck, ski and one side of
the radio box top. Set these on waxed
paper while they cure.
Repeat with a second coat and allow to
cure.
Every part needs 2 coats of epoxy sealer
before we can finish up.
Allow to cure overnight.
Sand the top of the tub, so that the sheeting
has a flat surface for gluing.
Check the fit of the tub top. If you installed
the radio box lid frame correctly, it should fit
without issue.
If all is well, glue the tub top sheeting in
place with 30 minute epoxy. Make sure that
the sheeting is flush with the transom and is
centered. Tape and weight until cured.

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Pine tub nose block in place.
Sand to match tub.
Pretty sweet nose rounding…
Once the top sheeting has cured, sand the
front of the tub flat and square. Glue the
pine tub nose block to the front of the tub.
Shape the block to match the tub.
Finish the nose block with a round, blunt
nose.
Nice and blunt.
Sponsons
The sponsons are assembled in a specific
order for a reason. It is not the fastest way,
but it’s the only way it can be done right.