Racing Sparrow Ranger 695 3D

1. Overview

The RS-Ranger-695-3D is a 3d printed radio controlled yacht. By design it's the simplest boat build we offer at Racing Sparrow. This build is suitable for ages 10 and above.

2. Preparation

2.1. Decide Boat Specification

Before printing any of the boat parts it's a good idea to decide what size bulb and what size sail you are going to build. The 3d print files comes with 3 bulb weights, 530g, 610g, 680g. The sails come in sizes A, B, C.

When testing we found the overall best combination that sails well in a variety of breezes to be the 610g bulb and B size sail. This gives a wide range of sailing conditions for one set of appendages.

You can of-course build multiple keels and sails and interchange them for the conditions. Using a C sail with a 680g bulb allows the boat to sail in some fairly rough sporty conditions!

2.2. Tools Required

These are the tools you will need to complete the build. None of these tools are mandatory, you may be able to do the job with what you have. This list makes the job easy.

Craftknife
Dremel
Drill
Small plyers
Scissors
Hammer, small one is great
Small round hobby file
Needle
Metal Ruler
Sandpaper
Marker Pen

2.3. Print Colours in Batches / Filament Choice

Print part colours in batches, like green hull, white keel and rudder fins and dark blue components.

It really helps before you start to figure out the colour combos to save you extruding and retracting more than you need to.

At RacingSparrow we use mostly PLA+ to print all the parts but have also used standard PLA, clear PLAs, silk PLAs. All of these materials are great to use. We do find that PLA+ can withstand more punishment and is a little more heat resistant than other PLA's.

3. Hull Build

3.1. Hull Preparation

A - RS Ranger - Hull Stern.stl
B - RS Ranger - Hull Mid.stl
C - RS Ranger - Hull Foredeck.stl
D - RS Ranger - Hull Bow.stl
E - RS Ranger - Hull Nose Cap.stl

Masking Tape

Clean up the printed parts carefully, mainly around the joins with sandpaper, craft knife, and file.

Masking Tape the hull joins on both sides of the joins so when you glue them together you don't get glue over-run at the joins.

3.2. Hull Anchor Disks

B - RS Ranger - Hull Mid.stl
C - RS Ranger - Hull Foredeck.stl
H - RS Ranger - Anchors + Washers x 2.stl

(CA Glue) Superglue
Split pins (25mm x 3.5) x 2

Build two sheet anchors by bending a split pin with pliers around the printed part. Tape around the hull holes to stop finger marks. Glue the anchors from inside the hulls with superglue. Make the loops front-facing.

3.3. Hull Assembly

A - RS Ranger - Hull Stern.stl
B - RS Ranger - Hull Mid.stl
C - RS Ranger - Hull Foredeck.stl
D - RS Ranger - Hull Bow.stl
E - RS Ranger - Hull Nose Cap.stl

(CA Glue) Superglue

Super glue the hull together starting from the back of the boat and work forwards. Use plenty of glue to ensure the joins are water tight.

Now that the boat is now one piece and while the tape is still on the hull, run a bead of superglue along each join, then quickly wipe away the excess with a clean rag. This will seep into the gap and weld the joins together.

Remove the tape straight away before the glue sets completely.

3.4. Hatch Opening

P - RS Ranger - Hatch Plate.stl

Use a marker pen and complete the circle where to cut the hatch supports.

With a Dremel disk or cutting tool, cut off the print supports. A Dremel sanding disk is a great way to clean up the cuts. Test place the hatch plate multiple times and keep tidying the hole until it sits flat.

Set aside the hatch plate for now, we'll glue that down further along the build process.

3.5. Rudder Cassette & Gudgeons

I - RS Ranger - Rudder Cassette Bottom.stl
J - RS Ranger - Rudder Cassette Top.stl

(CA Glue) Superglue
Carbon Rod Round 4mm - (50mm length)
Rudder Control Rod & Clevis

With the rudder inside the cassette, super glue together the two rudder cassette halves. Keep sliding the rudder slightly so it does not glue in place.

Cut the 4mm carbon rod for the rudder connection.

Attach the rudder cassette and gudgeons by tapping the carbon rod through the holes. The fit should be snug but removable.

Attach the Z-bend rod to the rudder cassette. You need to glue the rudder cassette in place with the z-bend pre-attached. It's much harder to do afterwards.

Glue gudgeons in place with superglue. Top gudgeon flush with deck. Avoid gluing the cassette. Rotate the rudder after a few seconds to confirm free movement. Press firm as the glue sets for 20 seconds.

3.6. Sheet Exit Tube

A - RS Ranger - Hull Stern.stl

(CA Glue) Superglue
Brass Tube 1/8

First break off the print in place support triangle covering the hole and clean up the edges with a craftknife and/or file. Mark the brass tube length against exit hole with a marker pen.

Cut slightly oversize with a Dremel then file the ends until there is a snug press fit. Glue with small drops of superglue in each seat in the PLA.

3.7. Anchor Disk Sealing

H - RS Ranger - Anchors + Washers x 2.stl

Masking Tape
Epoxy Resin

Mix a small amount of epoxy.

Seal around split pins. Add printed washer to create waterproof seal. Masking tape helps prevent finger marks.

4. Electrics

4.1. Servo Plate & Electronics

L - RS Ranger - Servo Tray.stl

RadioMaster R86 Receiver
Sail Servo S3003
Rudder Servo
Power Switch On/Off
Small 3mm screws

Screw servos onto the servo plate. Test servos, receiver, and binding.

Install servo plate and route wires into the battery box. Screw servo plate into hull.

Battery compartment fits 4xAA or lighter 4xAAA packs. Pack smaller batteries with foam.

Note: there is a STEP file for the servo tray so you can 3d model your own plate if the servos you have are a different size.

4.2. Battery Box

M - RS Ranger - Battery Box.stl
N - RS Ranger - Battery Box Lid.stl

(CA Glue) Superglue

Glue the battery box lid to the battery box, then glue the battery box into the hull seat. It is designed to keep the weight as far forward as possible.

4.3. Rudder Setup & Centering

Rudder Control Rod & Clevis

Power electronics and centre rudder servo.

Attach servo horn and clevis. Aim for horizontal servo arm when centred. Fine tune with clevis adjustment and trim. Screw servo arm in place without over-tightening.

4.4. Sail Arm Installation

N2 - RS Ranger - Sail Arm.stl

(CA Glue) Superglue

Glue round servo arm to underside of printed sail arm.

With sails fully pulled in, install sail arm so it nearly touches keel centre case. Arm travel is 90 degrees and passes about 4mm above battery case.

4.5. Hatch Plate

P - RS Ranger - Hatch Plate.stl

(CA Glue) Superglue

Test fit hatch plate. Ensure sail arm does not rub.

Glue hatch plate to deck with firm pressure for 20 seconds, aligning centreline indent.

5. Keel Build

5.1. Keel Halves Assembly

S - RS Ranger - Keel Half.stl x 2

Masking Tape
(CA Glue) Superglue
Carbon Rod Round 3mm

Mask keel fully except glue end.

Cut two 75mm lengths of 3mm carbon rod. Glue keel halves together with rods installed.

5.2. Join Bulb to Keel

S - RS Ranger - Keel Half.stl x 2
Bulb 530 Main.stl
Bulb 610 Main.stl
Bulb 680 Main.stl

(CA Glue) Superglue

Super glue the Bulb Main part trough to the keel blank.

5.3. Carbon Reinforcement

S - RS Ranger - Keel Half.stl x 2
Bulb 530 Main.stl
Bulb 610 Main.stl
Bulb 680 Main.stl

Epoxy Resin
Carbon Square Rod 4mm, 4 x 400mm (check this)

Prepare area with cardboard. Mix epoxy while wearing gloves.

Coat four 4mm carbon square rods and insert fully into keel trench. Tap gently if required. Leave upright to cure.

5.4. Bulb Filling

T - RS Ranger - Bulb Join Key.stl
Bulb 530 Main.stl
Bulb 530 Nose.stl
Bulb 610 Main.stl
Bulb 610 Nose.stl
Bulb 680 Main.stl
Bulb 680 Nose.stl

Epoxy Resin
Lead Shot 500g
Mineral Turpentine

Place keel upright with bulb nose supported.

Fill bulb with lead shot leaving 1cm gap.

Mix 50ml resin thoroughly, then add 15ml mineral turpentine. Slowly pour resin allowing it to soak through lead shot.

Tap bulb to release air bubbles. Top up with lead and resin.

5.5. Final Keel Steps

T - RS Ranger - Bulb Join Key.stl

(CA Glue) Superglue
Spectra Rope 150mm

Once set, glue join key disk and nose.

Drill 4mm hole at top of keel for rope loop.

6. Rudder Build

K - RS Ranger - Rudder Blade.stl

(CA Glue) Superglue
Carbon Rod Round 3mm

Remove mouse ears if needed.

Cut 105mm length of 3mm carbon rod.

Mask top of rudder. Glue rod in place using superglue, tapping gently if needed.

Trim flush once cured.

7. Rig, Mast & Boom

7.1. Cut Mast & Boom Sections

Carbon Mast 6mm
Carbon Boom 5mm

Choose rig and cut mast and boom to plan dimensions.

7.2. Mast Fittings

U - RS Ranger - Mast Disk.stl
V - RS Ranger - Rig Spar Joiner.stl
W - RS Ranger - Boom Attachments x 2.stl
X - RS Ranger - Mast Top.stl

Test fit all fittings. Lightly sand carbon where fittings glue.

7.3. Mast Disk Installation

U - RS Ranger - Mast Disk.stl
V - RS Ranger - Rig Spar Joiner.stl

(CA Glue) Superglue
Carbon Mast 6mm

Slide gooseneck up mast.

Insert mast into hull, position disk so mast spins freely but cannot lift out. Glue disk in place carefully.

7.4. Gooseneck & Boom

V - RS Ranger - Rig Spar Joiner.stl

(CA Glue) Superglue
Carbon Mast 6mm
Carbon Boom 5mm

Glue gooseneck against disk with disc notch facing forward.

Glue boom into gooseneck.

7.5. Final Mast Components

W - RS Ranger - Boom Attachments x 2.stl
X - RS Ranger - Mast Top.stl

(CA Glue) Superglue
Carbon Mast 6mm
Carbon Boom 5mm

Position and glue boom attachment points.

Glue topper attachment aligned with boom.

8. Sail Construction

8.1. Workspace Setup

Use flat, cuttable surface such as scrap vinyl.

8.2. Sail Cutting

Mylar Sail Material

Cut sail rectangle from mylar to plan dimensions.

Cut mast and boom offsets to shape sail.

8.3. Sail Corners & Battens

A Rig - RS Ranger - Sail Corners.stl
B Rig - RS Ranger - Batten Set.stl
B Rig - RS Ranger - Sail Corners.stl
C Rig - RS Ranger - Batten Set.stl
C Rig - RS Ranger - Sail Corners.stl

Spinnaker Repair Tape

Tape printed corners in place using spinnaker tape.

Install battens using tape strips.

8.4. Leading Edge Tape

Spinnaker Repair Tape

Apply sail tape both sides of leading edge, stretching sail while taping. Trim to leave 5mm double thickness.

8.5. Lacing Sail to Mast

(CA Glue) Superglue
Braid Line

Stitch sail using one continuous braid line.

Cut braid into loop sections and tie reef knots.

Tie loops loosely around mast, allowing sail to shape naturally. Glue knots and trim ends.

8.6. Clew Adjustment System

W2 - RS Ranger - Bowsie.stl

(CA Glue) Superglue
Braid Line

Install bowsie system through boom fittings and sail eyelet.

Adjust for full flattening or ~2cm foot slack.

Add mainsheet loop to boom. Glue.

9. Main Sheet & Radio Setup

9.1. Main Sheet Routing

(CA Glue) Superglue
Braid Line
Fishing Clip & Swivel

Run sheet from sail arm, around copper tube, through anchor eyelets, to fishing clip via swivel. Glue knots.

9.2. Boom Angle & Trim

Boom should point toward back corner of boat when sheeted in.

Downwind travel reaches 90 degrees.

9.3. Radio Fine Tuning

Fine tune sail trim via transmitter.

Add exponential to rudder for fine control and reduced drag.

10. Ready to Sail

The boat is now ready to go sailing.

Printing Guide

The Racing Sparrow 3D boats are designed to be printed from PLA+. One roll of filament should be enough to print the hull parts, keel, bulb, rudder, and rig parts. The 3d model has been designed so that no part is too large making this easily printable on most home 3d printers. Minimum Printer Bed Size Required: 150×150×180mm (XYZ).

Simply load the STL files into the slicer software and start printing. All parts are pre-oriented correctly so you should not need to rotate.

The settings the author used on a Creality K1 Max Printer were: PLA+ eSun
Nozzle 0.4,
Wall count of 2: top 4, bottom 4 layers
Brim inside and out for adhesion for hull skins
Use mouse ear: part T1 for problematic lifting edges, (google ‘3D printing mouse ears’)
200°C Nozzle
60°C Bed
34°C Enclosure
35% infill
300mm/s speed

Carbon Fibre

Before gluing any carbon it’s best to sand off the glossy outer coating of the spar. These coatings are just thin layers added to the carbon by manufacturers. When gluing this will add much better bond of carbon and PLA+. It’s easiest to sand these with a dremel or it can be done by hand with sand paper. Wear gloves to avoid itchy hands from the cut carbon particles. Carbon glues well with both CA and epoxy glues.

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