Wednesday, 19 October 2011

Here's one I made earlier.

I've had literally hundreds of enquiries (well one actually) about the progress on Katie Beardie recently.

So its time for an update. 

Regular Readers will remember that Katie was launched back in July, but that was only to see where she floated, and if Cee Dubbs and I had got our assumptions right and that my ass was in the right place. 

Everything looked to be tickety boo so it was back to the Port-na-Storm research and design lab for some development work. 

Of course nothing happened for several weeks while I dealt with the ongoing pleasures and challenges of being son, husband, father, and grandfather, sometimes all in the same sentence.  I'm sometimes a brother too but my sister likes to have me all to herself on the phone. Usually for a couple of hours.  However, I digress..............

There are of course no detailed plans for Katie, well actually there aren't any plans at all, other than two sheets of A4 showing how to cut the ply for the planks, and I even managed to make a resounding cock up of doing that!  So when it comes to internal layout, rudders, centreboard, sailing rig etc. the world is indeed yours to doodle with. 

I love this aspect of the build, it reminds me of knocking up carts and rafts when we were kids.  You got an idea in your head and immediately started to build it with whatever happened to be lying around. Straight from your head to the wood. However it does mean you can waste a lot of plywood!

 I made my rudder and centreboard ages ago, because I like to get as many of the fiddly jobs as possible done before the hull is built. However it does require quite a bit of guess work if you haven't built the hull its going to go in yet. 

I decided on a centreboard because a) that's what the old Victorians had. b) I think it will work better than a lee board c) a centreboard fits snugly inside its case where a dagger board has to be lifted out and then it gets in the way. d) a centreboard acts as a depth sounder while a dagger board just trips you up. 

Of course the great big obvious elephant in the room is you have to have a centreboard case bang in the middle of the boat just where you don't want it. So the challenge is to try and make it as unobtrusive as possible while still trying to ensure it actually does its job as intended. 

And so, here we have it. A low profile case, with a longish board resulting in a high aspect ratio foil i.e. deep and narrow which should theoretically do the job. 

 After a conversation over at  HBBR  when Frogsider discovered the hard way that he had under engineered his rudder I consulted the good doctor and we agreed that the 6mm centreboard I'd made probably isn't going to take the lateral forces expected of it once I get in and the wind starts to blow. So after hunting around the garage floor a piece of 4mm ply was found and the two duly sandwiched together. Thickening up the board of course meant the case had to be widened so the old Japanese Pull Saw split the case and wider spacers were inserted. 

The jig-saw ripped a hole down the middle of the floor and the case was epoxied in against the new centre bulkhead.  At this point the horn on the centreboard had to go as it would foul the bulkhead. A little detail which hasn't quite been resolved yet.  You can also see where I've started to shape the side decks, the forward mast step and a hard-board template for the coaming. 

The eagle eyed will have spotted that the original board is as flat as the proverbial witch's, due to its lack of thickness so the opportunity was taken to carve some shape into the new wider board. 

While I was at it the rudder needed beefing up,  I also decided I didn't like the shape of the original so this time I just made a new one out of some spare 6mm and then gave it some profile to match the centreboard. 

Onward ever Onward............................................... 


Chris Waite said...

Small, Medium and Tremendous!

This is the considered opinion of the designer

What me biased?


doryman said...

Are you sure the board is in the correct fore and aft position?
(Just giving you a hard time, no offense meant.)
Be careful about making the aft edge of your foils too sharp or they will hum. (but then, you knew that)