AMYA Star45 How To Build R/C Model Sail Boat -

Building a wooden model sailboat made simple. Enjoy the pleasure of wooden model boat building. Based on the International Star Boat this semi-scale Star45 can be scratch built by novice or seasoned skipper. Easily radio controlled and large enough to see out on the water this is a model built by hobbyists for over thirty years, Downloadable plans {drawings, prints} on-line. Laser cut bulkheads available from hobby suppliers.
This is a member blog of Dave Mainwaring's Knowledge-Network

The Star 45 is a one design class of model yachts

PondYachtworks in Scottsdale, AZ.

American Model Yachting Association Star 45 Class

The Star 45 is a one design class of model yachts recognized by the American Model Yacht Association. This boat is 45" long with a minumum weight of 12 pounds. The design is a semiscale model of a International Star. These boats can be scratchbuilt, from a kit or purchased complete.

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What about keel shapes and keel-bulb design

The Star 45 R/C Model Sail Boat - Builders Journal

"Dave Mainwaring"
Someone asked about shapes and sizes.

I like keels that resemble in some manner the "Scheel Keel". Flat bottoms help fight heeling. My version was based on my sailing in waters with lilies and pond grass that snagged torpedo shaped bulbs. I liked being able to back away and have the crap slide off the keel.

http://photos1.blogger.com/blogger/5587/620/400/Sirius%2045%2006.jpg

http://photos1.blogger.com/blogger/5587/620/400/Sirius%2045%2002.jpg


Here is a photo of the original Mainwaring Keel and Mainwaring Bulb

http://photos1.blogger.com/x/blogger/5587/620/400/353321/Sirius45Keel.jpg

S45 Rigging Bill of Material from John Fisher

Building Displaying Sailing
Model Boats and Ships

S45 sail boat Rigging Bill of Material from John Fisher
To:Star45@yahoogroups.com
From: 'J Fisher'jfisher@wildblue.net
Sender: Star45@yahoogroups.com
Date: Wed, 3 Jan 2007 21:02:38 -0700 (Mountain Standard Time)
Subject: Re: [Star45] Deck rigging and such

Here is the list on the star 45 yahoo groups for rigging. I am using the following for my next couple of builds:
GBMY item #, description, qty, purpose
019, 3/8' alloy tube, 1, Jib boom
034, Hales single block, 2, main and jib sheets
146, tapered drain plug, 1, plug in transom
182, Z sheet hook, 2, sheet ends/boom attachment
202, large bowsie, 1, back stay/forestay with 80 lb Dacron, order small ones if using spektra
206, O-rings, 1, hold the Z hooks to the boom.
254, double block, 2, main sheet and jib sheet adjuster
255, sheet exit, 1, turning block for main sheet from under deck to above deck.
269, eye plate, 1, mounting for jib block.
272, 180 deg sheet lead, 1, turn around for jib tweaker
280, sheet hook, 1, hooks for backstay and fore stay.
282, tang, 1, attach lowers to mast.
907, rigging screw, 4 hooks, 2 packs, upper and lowers to the deck.

I also build my own chain plates, so I don't order them from GBMY. Don does carry them if you need them. I also like the Ludwig mast better than the bantock mast, so I ordered 8 foot masts cut to 69' from Larry Ludwig, the other 28' or so is the main boom. Last time I made all my own boom vang, mast fitting. This time I ordered them from Larry. You can use the bantock mast, boom, and fittings from GBMY as well. They are good stuff and I have them on my IOM.

The back stay crane is made from 1/16 (.063') aluminum that I bought at the local hobby shop.
John Fisher
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photo's courtesy of "Larry Ludwig" at www.LudwigRCYachts.com, Ludwig Mfg.

Star45 What is a hull ? Dave's construction categories, unofficial

Model Sail Boat Building, How To Build A Wooden Star45 R/C Sailing Model: What is a hull ? and construction categories

A composite hull:
a hull constructed of wood and covered with reinforced plastic (cloth impregnated with resin).

OR:
a hull constructed using a laminate (sandwich) consisting of reinforced plastic (cloth impregnated with resin) on two sides of a core . Core materials may be foam or wood.

Jib booms, radial jib fittings and vangs

The mainsail and jib on the Star 45 are self tending. That is they can swing from side to side as the model tacks without requiring the sheets to be tended.

Originally on the old model the jib was loose footed and did not use a jib boom (aka a jib club). The addition of a jib club allowed the jib shape to be controlled.

Like the main sail the foot of the jib will fly up is some type of vang is not in place. Typically a swivel is placed along the forward end of the jib boom and clipped to a deck fitting (aka jib rack).

Look at the jib as a triangle. The halyard pulling the head of the jib places a force on the jib swivel. As the swivel is moved forward and aft along the jib boom the leach of the sail has more or less ability to rise. The head of the jib also moves off center.

It is possible to find jib boom fittings that anchor the forward end of the jib to the bow and use a vang to control the lift of the boom. These are known as radial jib fittings. The jib stay attaches to the radial fitting. This has the advantage of staying taught against the back stay as the sails are trimmed,

The jib boom and swivel also pull against the back stay. Since the jib stay attached to the jib boom in this arrangement moves off center and is subject to varying wind forces the tension on the jib stay and back stay will vary.

The driving force of the sails is changed when the slot between the mast and jib changes. Finding the best spot for the mast and jib swivel/radial fitting adds the challange of setting up the sails prior to sailing.

Jib Tweaker VS Jib Twitcher

The Star 45 R/C Model Sail Boat - Builders Journal
A Jib Tweaker adjusts the length of the jib sheet.
A Jib Twitcher pulls the job boom wing on wing while sailing  down wind

Drum Servo with Jib Tweaker from Dave Ramos To: Star45@yahoogroups.com
Sent: Fri, 14 Nov 2008 10:23 am

The following photos show my set up for a drum servo and jib tweaker.

Hope this helps David Ramos, Chesapeake Performance Models
227 Main Street, Stevensville, MD 21666
email: david@rcyachts.com
www.rcyachts.com

From Dave M.

 Jib Twitcher:

Sailing Model, AMYA Star45 Class | transom details

View of Transom construction.

Wood choices and AMYA rules for Star45 Class

Hulls may be planked using any number of types of wood, including thin aircraft plywood, cedar, balsa, etc.

The Star 45 is a terrific boat for sport sailing and family fun. If you want to race other Star 45's you should build to the AMYA Class rules.

Here are key 2006 AMYA Star 45 Class Rules,section 1.0 Hull:

1.1 The Star 45 Class establishes as their approved plans a set of lines and drawings as the approved reference and construction plans for the class. These plans are scaled and appropriately modified for the use of modelers building a 45-inch model of the Star Boat. Existing plans supplied by kit manufacturers, etc. are grandfathered. New molds, plugs and scratch built models shall conform to the approved plans and specifications.

1.2 Hull length will be 45 inches (plus or minus one half (1/2) inch overall. (NOTE: this does not include any chain plate for backstay attachment, or 1/4 inch bow bumper if used. However, if the chain plate is attached to the transom or overhangs the transom, it may not extend beyond the transom more than 3/8 of a inch.) Hulls may not be less than 11 inches nor exceed 12 inches in beam when measured at the widest point on the deck. (Rubrails are not included in measuring but will not exceed 1/4 inch of thickness/width.)

1.3 In the event of a builder choosing to scratch or hand build a Star 45 Yacht, the builder must adhere to the class approved reference and construction drawings, as obtained from the AMYA Ships Store, as in the builders ability. A second consideration in scratch building is to ensure that safe and sound building practice be maintained.

1.4 All hulls will be constructed of wood or fiberglass or a combination of wood and fiberglass and be a minimum of 16 ounces when weighed before attachment of the deck and keel. This weight must be verified by another member of the Star 45 Class using the Class Measurement Form.

1.5 Decks shall be constructed of wood, fiberglass or plastic laminate material.

1.6 All hulls shall be the standard hard-chine hull. Hulls may be built with a sheer at scale height or with a sheer no more than one inch higher than scale (when measured at the point of maximum depth of sheer.)

1.7 All fiberglass and wood hulls will have a name plate permanently attached to the inside of the hull so as to be seen when the hatch cover is removed.

1.8 At or before its first Sanctioned Regatta the newly built model yacht must be measured using, as reference, the approved measurement form and signed by not less than the owner of the model yacht and one other member of the class. This measurement form shall become, with the registration card, a permanent record of this model yacht.

1.9 The AMYA Star 45 Class recognizes and approves the molds and manufacturer and/or kit packagers of Star 45 molded hulls and kits in existence at the time of approval of these specifications. These sources will be approved sources for the class. New manufacturers will be directed to submit the first of their product to the Class Secretary for approval.

1.10 No maximum weight is specified, however, no yacht will weigh less than 12 pounds when fully rigged ready to sail. This means with all gear, rigging, sails, radio components, batteries and ballast placed and secured on board.

1.11 Bow Bumpers are mandatory for all class registered STAR 45 yachts. Bow bumpers are limited to three eight's of an inch (3/8") overhang. Bow bumpers shall be excluded in the overall length measurement, whether recessed in or otherwise attached to the bow stem. Bow bumpers must be of resilient fabrication to minimize damage to another yacht in the event of a collision.

Lester Gilbert on sail making for model sail boats

Model Boat journal

Lester Gilbert on understanding of sail making for model sail boats
Lester Gilbert wrote:
For anyone interested in sailmaking, I've just finished editing Larry Robinson's "Making Model Yacht Sails" (part 1 only) booklet and have published it as an "international" edition. I've done this, not to get rich ('cos this isn't going to happen to either me or Larry or anyone else connected with this enterprise!), but because I've spoken to a lot of sailors who want to make sails but don't know the "right" techniques, and who are being misled by incorrect accounts of how this might be done.


A sail block

(Illustration from Larry Robinson's "Making Model Yacht Sails")

From my understanding of sail making, there are two ideas I want to contradict.

The first idea is that you can make sails by accurately cutting a curve on a panel, and then attaching it (stitching, gluing) to another panel. Well, while you might be able to cut a good curve some of the time, your fingers just don't have laser accuracy in them to stick A to B and you'll hardly ever obtain reproducible or reliable results. (It might be possible to butt-join the curved edge to another curved edge with a little more reliability, but this doesn't yield what the Equipment Rules of Sailing define to be a seam. Such a sail couldn't be used in sanctioned IOM competition, though it would be OK in a development class.)

The second idea is that you can drape your panels over a "camber board" and get a nice shape that way. Well, let me be clear about what I'm knocking here. I take a "camber board" to be a length of curved surface, where the curve is like the surface of a cylinder. In this case, your panelled sail will have exactly the same shape as a single un-panelled sail and, if you wanted a three-dimensional shape, you've wasted your time (though the result certainly looks the part).

Larry's booklet is the only source I know which carefully explains the use and construction of a sail block. I am sure that this is really the only way (in your garage, please, not in some specialist workshop!) to make professional sails, to obtain reliable and reproducible three-dimensional shaping, and to be able to tweak and change your shaping as you learn about the whole business.

(Warning: Y'all should know I have ten thumbs and have never made a sail yet. What I have done carefully is to watch and talk to those who do, both professionally and as home builders, and measure the results. Making Larry's booklet available internationally is my way of telling you what I've learned.)

Bob Wells will be able to ship this within the USA, and I expect that it will also be available from Don Ginthner at GBMY. For worldwide sales, contact SAILSetc. Bob Wells' e-mail is "bob" at "islandinet.com", GBMY is "rcsailing" at "gbmy.com", and SAILSetc can be contacted through "sales" at "sailsetc.com".

I've attempted an analysis of how blocks work on a new page, Sail blocks analysis, and have a new spreadsheet there to help.

to drill and tap wood (bass wood) from RodCarr@carrsails.com via yahoogroups.com

Drill a proper sized pilot hole. Load it with thin CA. Tap your thread. 5-40 or larger will work reasonably. Smaller than that, not so much. Rod Carr

S45 Class Sailboat Plans {line drawings} on-line

Model Sailboat Plans on line

Most browsers will allow you to right click and open the jpg images. You can then save them to your machine.

This set of plans are based on drawing from John Fisher 2006. John may have new and updated drawings available. Check with http://groups.yahoo.com/search?query=star45 membership required.

I want to thank J. Herrmann, www.graphicLanguageOnline.com, for his assistance in converting pdf's to jpg drawing, adding color to the templates and adding the grid to the final images

You can print these drawing to many different sizes.They are not necessarily to scale.

Star45 Hull Templates and shadows

The grid shown is set to 1/4 inch squares. So if you print the templates you can check the size by making sure the grid yields a 1/4 square.

Modelers will use different building materials for the model.These are JPG drawing and print outs may require adjustments to get the widths to correct sizing. For a Star45 AMYA class you need to make adjustments to allow for planking thickness. The rules establish the maximum allowable beam dimension and hull length.

Most browsers will allow you to right click and open the jpg files. You can then save them to your machine.

This set of templates are based on drawing from John Fisher back around August 2006. John may have new and updated drawings available. Check with http://groups.yahoo.com/search?query=star45 membership required.

If you want to scale to use for different model you can change the print out to give you a different grid size.

I want to thank J. Herrmann, www.graphicLanguageOnline.com, for his assistance in converting pdf's to jpg drawing, adding color to the templates and adding the grid to the final images.Rudder templates for a Star45 Class sailing model.The grid shown is set for 1/4 inch squares. So if you print the templates you can check the size by making sure the grid yields a 1/4 inch square.

This set of templates are based on drawing from John Fisher. John may have new and updated drawings available. Check with http://groups.yahoo.com/search?query=star45 membership required.

I want to thank J. Herrmann, www.graphicLanguageOnline.com, for his assistance in converting pdf's to jpg drawing, adding color to the templates and adding the grid to the final images.



These are half shadow that ar eplaced between the templates to add strength to the hull.

Star45 sailing model plans

Most browsers will allow you to right click and open the jpg images. You can then save them to your machine.

This set of plans are based on drawing from John Fisher 2006. John may have new and updated drawings available. Check with http://groups.yahoo.com/search?query=star45 membership required.

I want to thank J. Herrmann, www.graphicLanguageOnline.com, for his assistance in converting pdf's to jpg drawing, adding color to the templates and adding the grid to the final images

You can print these drawing to many different sizes.They are not necessarily to scale.

S45 Frames (aka bulkheads, shadows) on Mainzone.com

Every man, woman and child should enjoy the pleasure of building a wooden boat

The MainZone web page contains links to downloadable files for use in building the Star 45

This model is is built using frames otherwise known as shadows or bulkheads. The files for these frames reside on www.mainzone.com.

S45 Construction templates for laminating rudder

Rudder templates for a Star45 Class sailing model.The grid shown is set for 1/4 inch squares. So if you print the templates you can check the size by making sure the grid yields a 1/4 inch square.

This set of templates are based on drawing from John Fisher. John may have new and updated drawings available. Check with http://groups.yahoo.com/search?query=star45 membership required.

I want to thank J. Herrmann, www.graphicLanguageOnline.com, for his assistance in converting pdf's to jpg drawing, adding color to the templates and adding the grid to the final images.

Star 45 Construction templates Keel fin

Building templates for S45 Keel fin.
Originals drawings are based on 1/16 ply.

Modeler may want to use different building materials for the fin.
Final keel fin will be shaped the builder. Also these are JPG drawing and print outs may require adjustments to get the templates to correct sizing.

The grid shown is set for 1/4 inch squares. So if you print the templates you can check the size by making sure the grid is a 1/4 square. If you want to scale the keel fins for another model you can change the print out to give you a different grid size.

This set of templates are based on bolt mounting. The grid makes it easy to add to the template to have the keel extend into the hull or extend into the keel bulb. Modeler's choice.

Most browsers will allow you to right click and open the jpg images. You can then save them to your machine.

This set of templates are based on drawing from John Fisher 2006. John may have new and updated drawings available. Check with http://groups.yahoo.com/search?query=star45 membership required.

I want to thank J. Herrmann, www.graphicLanguageOnline.com, for his assistance in converting pdf's to jpg drawing, adding color to the templates and adding the grid to the final images.

RE: slots in (laser cut) frames and stringer from old forum notes 8.31.2010

Ray wrote: >
need to know what are the vertical > slot in frames 4,5,and 6 for also what size stringer goes into frames right > at the bottom where the bottom of hull meets the side of the boat also there > seems too be a slot for another brace on frames 4,5,and 6 directly under the > vertical slots.
Thanks Ray from Down Under

the vertical slots are for the radio tray if you use it. the extra vertical slots by the king plank are just extra strength for the keel area. Chines are 1/4" X 1/4" or 6.4mm sq.

John On 8/30/10,

The Star45 Model Sail Boat, A radio controlled, R/C, Sailing Model

The Star 45 is a 45" long hard chine hull; semi-scale model of the full-size Olympic Star. They weigh 12 pounds plus, have 12 inch beam. They are easy to scratch build and sail. Well suited for building by by the novice builder and by the skipper looking for a classic looking model to race.

Hull stringers (aka rails)

Photograph by John Fisher

Start at the transom with the rails and stringers. Start one side and go forward to station 9 or 10, then do the same on the other side. Then go all the way to the front with one side. Starting both sides at the same time keep the transom from twisting.

Photograph by John Whiteford

Steps toward building a sailing model

Building Displaying Sailing
Model Boats and Ships

So you want to build a sailing model
Find plans for a sailing model, buy or find on-line.

Join a model boat forum for advice.

Buy or borrow books on boat building.

Decide on type of planking and wood to be used to build the model.

Set aside a work space for building.

Review the bill of materials need to build the model and buy the materials.

Order deck and mast fittings.

Order mast (if you are buying the mast) and order sails (or sail material).

Choose the radio system, buy a sail control unit, Order keel bulb or get advice and discuss issues of building your own.

While the hull is under construction build:

Keel fin and ballast bulb

Rudder assembly

Make or assemble spars ( mast and booms)

Build cradle to hold boat under construction and when finished.

Test Radio System and sail control unit

After hull is planked:

Install keel trunk or make provisions for mounting keel.

Install radio and sail control unit, Then remove while construction continues.

Construct deck and hatches

Install/mount deck fittings

Test access to radio and sail control inside the hull.

Provide a exit guide for radio antenna so it can be attached to mast or stays.

Install power switch for turning off batteries

Test mount keel

Paint hull, rudder and keel

Assemble hull, rudder and keel

Set up mast and boom.

Install radio controls.

Check running rigging.

Attach Sails

dry sail model

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Sail
Display
Storage

Star 45 Rudder Construction, using laser cut laminations

Star45 : Message: Re: [Star45] naca0009 rudder: "Re: [Star45] Photo's of naca0009 rudder

I am happy with how they turned out. I sent the production files to Stevens Monday, so you should be able to order a rudder if you need one. He doesn't have it posted yet, but if you call him he can cut them for you.
I built mine by clamping all the pcs together with the alignment pins in place (1/8 sq stock left over from stringers). Then CA'd it together with thin CA. I used my random orbital sander with 150 grit to shape it. Took about 15 min or so. With the different layers you can see if you are removing material evenly. Once sanded I sprayed the rudder with 3M 77, covered with 3 oz glass, one PC folding it over the leading edge so there is no seam on the leading edge. I then added resin and vac bagged in my handy food saver. The next day I pulled off the breather and peel ply, sanded smooth and varnished.

The glass is probably not needed since the core is made out of ply. I used the glass to ensure it is not coming apart and only adds another 10 min or so to do. With the vac bagging it is very smooth and uniform with only a little sanding required to remove the texture of the peel ply. I did buy a yard of breather and peel ply, but waxed paper with holes in it and paper towels can be substituted."

Drawings are available from the Yahoo Star45 group "files"

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