PTI PX 300 User manual

PX 300
P–Limited High Performance
Tunnel Hull Kit
Specialpointsofinterest:
Afullframeupwooden
kit
Includesallwoodto
makethehullandradio
box.
LexanorFiberglasscowl
DesignedfortheOSLow-
erunitandanyPLimited
motor
PX 300
INSTRUCTION MANUAL
Developed by Mike Luszcz of ML Boatworks, the PX300 FE has a
completely new ride pad surface with variable
dihedral technology, and is a full frame up kit.
The kit is now available with a Lexan cowl (guarantee from crash
damage for life), a white gel coated fiberglass cowl is also availa-
ble.
This hull is designed specifically for 4s P-limited lipo power sys-
tems.
The PX300 currently holds the SAW P O/B tunnel record
in IMPBA
Won the 2012 World Tunnel Champions in Charleston,

`Getting Started
Before you get started you will need:
A flat building surface, we recommend piece of wood 1/2” to 3/4” thick. About 12” wide and 36” long.
We also recommend covering the side you will build on with wax paper to prevent the parts sticking to the
building board
Things to know before you start
Please review the parts list located at the back of this manual. Become familiar with the sheet name and the parts located on them
Your PTI boat kits was cut with a Laser Cutter specifically designed for plywood. Small tabs are left to hold the pieces while they are being
cut. To remove the piece press gently near the tab and the part should push out. HOWEVER if it does no come out easily we recommend
cutting the tab with a hobby knife as shown below
Page 2
Introduction
Tools required
Hobby Knife
Hobby Saw
Various C Clamps or Spring clamps
Masking Tape
Super Glue (CA) we recommend the “Thick” formula
Sanding Block
Sand Paper
30 Minute Epoxy Glue
Epoxy Resin
Small paint brushes
Optional:
Stanley “Sure Form”
PLEASE NOTE: All these items are available on our web site, please see
our online store
TAB

PX 300
Instruction Manual Page 3
Build the Sponsons
Step 1
Sponson Formers
A: Locate formers 1L thru 13L and 1R thru 13R from CENTER SECTION and SHEETING SHEET1.
B: Locate Sponson Keelsons from SPONSON SHEET
C: Place wax paper on your building board
D: Clamp the “LEFT SIDE” Sponson Keelson on the edge of the building board as shown. BE SURE to use enough
clamps so the keelson lies flat on the building board.
E: Insert former 1L in slot 1 and Former 2L in slot 2, continue till 13L is installed as shown in pic E. Do the same thing
for the right side
Formers
Sponson Keelsons
Left Side
C D
NOTE : this is a picture of the right side installation
We are showing how the number should match.
Do this for formers 1 thru 13 L and R
Doublers

Page 4
Inside Story Headline
Build the Sponsons Con’t
A: Locate Former #1 Doubler from CENTER SECTION
B: Glue to former 1 as shown, be sure the edges line up
C: Use a triangle or combination square to check perpendicularity and clamp together as shown
Sponson Formers
B C

Page 5
Step 2
Sponson Shear
A: Locate Sponson Shear from CENTER SECTION
B: Starting from the front Insert the shear into the sponson keel as shown BUT glue it AFTER you’ve test fit formers
C: While holding the front in place, align the former with the notch in the sponsn shear as shown
D: Work your way down the sponson keel, sliding the former into the notch and into the notch in the sponson keelson
E: Once all the formers are in place check to be SURE the sponson shear is flush with the end of the former as shown
F: Press the shear down gently to be sure its seated on the sponson keelson then using CA glue tack the formers in
place being sure to put glue on the former and sponson keelson and the former and sponson shear
D
Build the Sponsons Con’t
B C
E
Glue
Glue

Page 6
Build the Sponsons Con’t
Step 3
Sponson Nose Doublers
A: Locate Sponson nose doublers from SPONSON SHEET
B: Glue on both sides of the Sponson keelson as shown, clamp as shown until glue dries
C: Using your sanding block, sand flush with the sponson keelson, be sure to do top and bottom
B
Step 4
Sponson Stringers
A: Locate the 34” long 1/8th” Square Basswood sticks
B: Put one stick into the notch in the #1 former as shown
C: Press the stinger into all the formers
D: Mark the stringer where it touches the sponson doublers , remove stringer , cut where marked re-install stringer and
glue into place
B C D
C

Page 7
Build the Sponsons Con’t
Sponson Stringers
E: Repeat this for both ride surface stringers and non trip stringer and both left and right sponsons
F: BE SURE all stringers are flush with the formers… Then glue as shown to all the stringers and formers
Glue

Page 8
Build the Sponsons Con’t
Step 5
Sponson Sheeting
Outer Edge
A: Using a sanding block sand the outer edge surfaces flush with the former as shown
B: Locate Sponson “outer edge” from SHEETING SHEET 2
C: Test fit outer edge making sure the edge is flush or has some over hang on BOTH top and bottom stringer AND
making sure the sheeting lies flat on the stringer
D: Glue both sides of the Sponson Outer edge as shown, clamp as shown until glue dries
Note the over hang
A
C C
Non–Trip
Outer Edge
Secondary
Ride Pads
Builders Note:
BEFORE you start the next step we recommend experimenting with the Sure Form to see how it behaves. Pulling in
one direction seems to give some chattering and difficulty pulling and a rough finish. Pull in the opposite direction and
you would get nice clean pull and finish.

PX 300 Page 9
Build the Sponsons Con’t
Sponson Sheeting
Non Trip
Step 6
A: Start with your Sure Form if you bought one, if not a sanding block will work fine, sand the outer edge surfaces flush
with the former as shown. Once its close, use a sanding block to finish, work length wise down the sponson so the edg-
es are uniform
B: Using a straight edge lay it across the former to be sure the sheeting lays flat on the former, outer edge sheeting and
the former. NOTE you will see a slight bevel on the sheeting and the former as shown
C: Locate Sponson “Non Trip” from SHEETING SHEET 2
D: Test fit sheet as shown making sure the sheet is flush or has some over hang. BE SURE TO LEAVE 1/8” See the
picture on the next page
E: Glue into place, Using masking tape to hold in place, clamp to the building board while the glue dries to prevent
twists in the sponsons
NOTE: BE SURE to use plenty of masking tape, its very important the sheeting is flash with all the stingers and bulk
heads.
A Note bevel
B
D
Masking tape omitted
for clarity

Page 10
Sponson Sheeting
Non Trip
Once the glue is dry, remove the tape and sand to shape as shown
Build the Sponsons Con’t
This picture is in error this
should only be 1/8” overhang
D

PX 300 Page 11
Step 7
Sponson Sheeting
Ride Pad
Ride Pads
Sponson Tops
A: Sand the bottom of the sponson. Using your SurForm (or sanding block) sand down the non-trip overhang close to
the stringer. When the entire sponson is close, use a sanding block to final sand the entire ride pad area.
Please note you are trying to sand this so that the pad is a flat surface such that the non trip sheet is flush with the
stringer and the sponson keelson are at the same angle as the former.
Building note: Use a block as shown below, trying to use long strokes front to back
To check the surface we recommend a straight edge as shown in the picture on the next page
Build the Sponsons Con’t
A

Page 12
Sponson Sheeting
Ride Pad (con’t)
Build the Sponsons Con’t
Your’s should look like this
Note Angle
Note flush with stringer

A: Locate the “Ride Pads” from SHEETING SHEET 1
B: Test fit the pads to be sure the sheeting lies flat on the stringer and formers
C: Mark to over hang, using a ruler or a piece if the 1/8” stringer. Place at the end of the ride pad and draw a line as
shown
C: Trim the rid pad to shape, the ride pad is made larger to insure the inside edge of the sponson can be made sharp.
So it will require some trimming. To do that we recommend you
D: Align the over lap then locate the ride pad so it slightly over hangs the non trip sheet. Clamp or tape in place
PX 300 Page 13
Sponson Sheeting
Ride Pad (con’t)
Build the Sponsons Con’t
C C
D: Align the pad so there is plenty of overhange on the inside of the sponson
E: Mark the outer edge with a pencil as shown

Page 14
Sponson Sheeting
Ride Pad (con’t)
Build the Sponsons Con’t
A: trim and sand BE SURE to keep this edge sharp.
Builders Note:
The next step is very critical, for the best performance, its very important the sponson remain straight. This step should
be done carefully because it is very easy to build in twist during this process.
We have developed two method to install the pads to insure the sponson remain flat.
The first one is the elevate the sponsons method
A: Place two of the 1/8” square sticks on your building board
B: Clamp the sponson on the spacer. This will allow the overhang on the inside edge to not interfere when gluing
Sticks
A
C
C

PX 300 Page 15
A: Align the sponson over hang as before,
B: Align the pad so it over laps the non trip sheeting as shown,
C: Align the front of ride pad as shown and clamp in place, be sure its the same over lap all the way forward
D: hold the ride pad against the frame as shown and tack glue if from the inside , work your way forward going one bay
at a time
IMPORTANT!! Use small amounts of glue to start..Take your time BE SURE the glue is hard before you move on
When you’ve finished, check the entire ride pad is flat against the frame work. Then go back and glue completely
Sponson Sheeting Con’t
Ride Pad (con’t)
Build the Sponsons Con’t
C
A B
C
D D
WARNING: This photo is in
error. Leave an 1/8” over-
hang, it will get trimmed later

Page 16
Alternate Rid Pad Sheeting method
Build the Sponsons Con’t
This outlines an alternate method to glue the ride pad on to the sponson. It requires a rigid straight piece of wood or
metal, we used aluminum angle..
A: Clamp the sponson to the angle as shown
B: Align the sponson over hang as before,
C: Align the pad so it over laps the non trip sheeting as shown
D: Align the front of ride pad as shown and clamp in place
E: hold the ride pad against the frame as shown and tack glue if from the inside , work your way forward going one bay
at a time
IMPORTANT!! Use small amounts of glue to start..Take your time BE SURE the glue is hard before you move on
When you’ve finished, check the entire ride pad is flat against the frame work. Then go back and glue completely
A
B D C
Note overhang the
length of the sponson

PX 300 Page 17
Sponson Sheeting
Ride Pad (con’t)
Build the Sponsons Con’t
Now the pads are glued down, we turn our attention to the sponson inside edge.
Using your Sure Form remove most of the excess ride pad… Finish with a sanding block to insure you sand it flush with
the sponson keelson. PLEASE BE SURE to keep this edge as sharp as possible
Use a straight edge to confirm

Page 18
Step 8
Sponson Sheeting
Secondary Ride Pad
Build the Sponsons Con’t
Outer Edge
Secondary
Ride Pads
A: Locate Sponson “Secondary Rid Pad” from SHEETING SHEET 2
B: To locate the secondary ride pads correctly on the rid pad, you need to measure 1 and 1/8” in from the inside of
the sponson at the rear of the sponson.
C: 10” up from the rear of the sponson place another mark 1 and 1/8” in from the edge of the sponson
D: There is excess wood on the pad to reduce sanding time we recommend aligning to both marks made then mark-
ing the edge as shown
B C C
Mark
D D

PX 300 Page 19
Sponson Sheeting
Secondary Ride Pad
A: Cut or band saw the excess BE SURE TO LEAVE an 1/8 of an inch or so
B: Align to marks again then glue into place. Tape reduced for clarity
C: Sure Form or sand flush with sponson keelson , keep this edge as sharp as possible
A Cut here
B C
Build the Sponsons Con’t
SHARP!

Page 20
Step 9
Sponson Sheeting
Sponson Top
Build the Sponsons Con’t
Ride Pads
Sponson Tops
A: Before we sheet the tops of your sponson, we recommend sealing the inter frame work. We suggest Epoxy resin as
its lighter, but you can use Polyester resin. We also recommend using fiberglass tape included in the kit
B: We suggest applying masking tape on the outer keelson to keep resin from leaking through to the mating surface
C: Cut pieces of the fiberglass tape to fit in each bay as shown
BUILDERS NOTE: While it is not necessary some builders add a bead of thickened epoxy alongside the strings in each
bay. This increases strength and allows the fiberglass tape to lay flat (see builders note pictures)
D: Brush resin on all the surfaces and to the tape so that it attaches to the frame. BE SURE to apply in all areas for-
mers and stringers. Do this in all the former bays in the sponson REMEMBER you are sealing all the wood in case wa-
ter gets into the sponson. One last thought, remember the more resin the more weight, so put on enough resin so to
wet the cloth and its translucent
B C