Model Boat Mayhem

The Shipyard ( Dry Dock ): Builds & Questions => Yachts and Sail => Topic started by: xrad on December 03, 2017, 10:42:59 pm

Title: XRAD'S EC12
Post by: xrad on December 03, 2017, 10:42:59 pm
Found fairly nice EC12 hull, few chips/dings.  Since I am not racing, not following spec so much in regards to sail size/min weight, etc..  Want this to be my beater sailboat, so I gave it a layer of 5oz cloth. Very strong hull now.

Built a simple winch setup. Has max 18" of travel and plenty of torque.  More than enough to run the sails and cost less than 50$ (35$ for 'winch' servo) and is programmed through the Tx so easy setup.  80lb fishing line. Spring auto tensioner needed as drum diameter changes as line winds on to extreme end of travel.

Got a 'groovy' round mast from online source. These are pretty much the standard across the globe.  6ftx 12.7mm dia is just right for this 58" hull. Unfortunately, the more scale extruded masts are not currently available from usual US sources, until someone extrudes more....

Title: Re: XRAD'S EC12
Post by: xrad on December 05, 2017, 11:09:18 pm
The sail winch is screwed to 2 grooved wild cherry blocks sitting on the 2nd and 3rd frames.  Easy to remove if needed. Reinforcing blocks extend under fiberglass lip at bow and stern for rigging. Have to design hatches ,mast support, chain plate support, rudder servo support....Sitka spruce stringers.  Spruce and cherry smell really good when cut.

I used devcon plastic welder to attach frames to hull.  Easy to mix, works great on polyester resin and wood!   expensive but worth it.  I used epoxy to reinforce the keel as hull was a bit thin there. Epoxy sticks fine to polyester once cleaned and sanded.
Title: Re: XRAD'S EC12
Post by: SailorGreg on December 06, 2017, 05:55:42 pm
Neat work. I can see the wisdom of having the winch removable, but how do you reach the screws when the deck is on? Perhaps I should be more patient and all will be revealed! It is nice to see another sailing craft being built.  :-))

Title: Re: XRAD'S EC12
Post by: danielcardona on December 07, 2017, 11:01:11 pm
Is this some sort of a J class sail boat, it has such a nice hull, so elegant  :-) . how did you figured out the shape of those formers? or were they with the hull?

Title: Re: XRAD'S EC12
Post by: xrad on December 09, 2017, 08:53:24 pm
Sailorgreg: Two hatches
DC: EC12 (hence the title  :-)) ) has lines similar to J boats, yes, very smooth and prototypical

The frames were all hand cut on an old sears reciprocating table saw w/16 inch throat (purchased in 1991 for my 5 foot clipper build!).  Bud Olsen aircraft plywood, 6 layers, very strong.  Simples to make stiff paper mock-up first, get that to fit well, then trace to the ply.  Another very helpful tool is the harbor freight 35$ (Special sale 3 yrs ago) table sander. Motor a little weak, but fine for small parts/surface areas...

Machined up a mast step out of aluminum. 1/2 deep socket for 1/2 dia mast.  Overkill on support system, but I don't want to have any issues.  Minimum recommended is 80lb line for the running rigging and 90lb stranded wire for standing rig. This could easily be made as an adjustable mount, but again, I'm not racing so just being built to last. Step is located about 25.25" from bow.  I strongly suspect that this mast will have a good amount of fore-aft play.  port-starboard play limited by stays/spreaders.  Unfortunately, can only currently get a round mast.  If I do find a more sturdy mast, I can easily make adapter to fit in socket.

More info on EC12  build sites and AMYA.  I purchased some very light kite material for the sails. Super cheap and super strong.  Classic Bermuda rig with 72" mast and 27.5" main boom plus a head sail or two should plenty of sail for this hull. 
Title: Re: XRAD'S EC12
Post by: xrad on December 10, 2017, 08:24:48 pm
wanted to go with 2 hatches, and have smooth deck...but needed three....

The largest rear hatch will be a cockpit and small house, the other two are just skylights, small low hatches..
Title: Re: XRAD'S EC12
Post by: xrad on December 12, 2017, 01:51:59 am
changed the middle hatch to a smaller size, looks better.  Easy to access winch track screws (3/32 allen head) from front and rear hatch. Middle hatch to check jib and main sheet attachment to winch line.  Don't really need the middle hatch as easy to undo two winch track screws and move whole winch track back to main rear hatch to fix anything....

Next step is the deck.  1/16 ply covered with light and dark planks....

I also have 18-20 lbs of shot ready to go into keel.
Title: Re: XRAD'S EC12
Post by: xrad on December 16, 2017, 06:46:45 pm
chain plate blocks installed. I will use 1" long 2-56 filister head screws and locknuts to fix a trimmed pikabe 358 fenestrated  aluminum mounts.  Deck base trimmed.
Title: Re: XRAD'S EC12
Post by: xrad on December 21, 2017, 09:09:35 pm
few more coats of poly-u to go... I wanted to use  Constructo 2x6mm strips, but hard to get. Had to use Dumas 1/16 x 1/4 strips, which are more rough grained and more roughly cut....
Title: Re: XRAD'S EC12
Post by: xrad on December 23, 2017, 12:55:28 am
Mast step (aluminum) , silver soldered bronze and brass for attaching goose neck(adjustable 3-48 ball end screw into brass block fixed in boom by 2-56 screw),..few more fittings to downhaul , and maybe pivoting spreaders...
Title: Re: XRAD'S EC12
Post by: xrad on December 23, 2017, 09:29:55 pm
Sail 'lofting'....

Designing and cutting the main. I did not build a 3D frame to cut the sail on, just eye-balled the foot and leech. Blue material is .75 oz spinnaker fabric from Sailmakers supply shop. 11$ sq yrd! I bought 2 yards, probably enough for 4 mains.. I also got some very nice 'kite' super light white 'rip-stop' fabric from China (for the jib).  Basting tape from local sewing shop. '000' chromed brass rivets and setter.  Can't cut the jib until I know the forestay layout...fractional or not...

1) Lay out a right angle x, y,  and hypotenuse, overall sized a tad smaller than the mast/boom
2) Added about 1/2-3/4" max curve to the leech, and about 1/2" max curve to the foot. used flexible tape to eye-ball the curve.
3) drew this in red on the workbench (next time I will use black, red did not show so well through the blue sail)
4) Laid out the material on a weave pattern I thought best
4) trimmed excess ahead of luff
5) taped down material and carefully hot-knifed it (hot knife OK...not great...have to go slowly...)
6) taped the head, tack, and clew
7) riveted points in #6 (need a punch or hot rod to make good holes)
8. used basting tape to fix dubro 518/883  crimps
9) looks OK for now...will see how she sails before adjusting  sail cut.....
Title: Re: XRAD'S EC12
Post by: xrad on December 23, 2017, 09:34:34 pm
more sails....

Spinnaker cloth is great; many colors to choose from, and very light and strong fabric....

Basting tape is applied to a clear plastic threaded sail material that someone gave me...don't know what it is....very strong material and does not pull apart like woven fabric....
Title: Re: XRAD'S EC12
Post by: xrad on December 24, 2017, 03:12:20 am
the hull was pretty messy with resin gobs and prior repairs.  I remembered that I had some left over polishing discs and cutting /polishing compound so gave it a whirl...

Lucky that there was enough gel thickness..good enough result (except for stern which had big chunk missing and will have to be painted)

Title: Re: XRAD'S EC12
Post by: xrad on December 24, 2017, 08:15:01 pm
deck fittings....
Title: Re: XRAD'S EC12
Post by: xrad on December 31, 2017, 09:51:25 pm
deck houses.....w/real glass
Title: Re: XRAD'S EC12
Post by: xrad on January 08, 2018, 08:32:31 pm
a bit more work to deck houses...