KnottyBuoyz III - The Project Update

[delmarrey]

Maybe this will help.

http://www.pagendarm.de/trapp/progra...les/NACA4.html

http://www.onemetre.net/Design/Bulbcalc/Bulbcalc.htm

http://www-berkeley.ansys.com/cfd/naca.html

[knottybuoyz]

Been to all of them Del!

I understand the concept just can't whip Autocad into drawing them properly! I just printed one out and photocopy enlarged it!

Gonna do a half scale model methinks!

I've been noticing that SS tube isn't any cheaper than solid stock. Both are expensive!

[delmarrey]

Originally Posted by knottybuoyz

I've been noticing that SS tube isn't any cheaper than solid stock. Both are expensive!

Yep! It's cost more to make tube then solid stock, especially in SS. The weight benifit wouldn't be worth it. Plus pipe is not really round, so the bearings would have to be a bit more sloppy to accomodate, if one were to go full length.

I made a 4" solid Titanium rudder shaft for a client a few years ago to replace a pipe shaft that was rattling around. That cost him a shinny new penny.

[44'cruisingcat]

Originally Posted by knottybuoyz

Hey Del

I'm going to use a solid shaft for the upper portion above the flange and into the boat. New drawing attached.

I think the foil shape will only be about 2-1/4" at the widest part. Gotta check that. The articulated rudder can be support on the top and bottom and there's 2 attaching points each. The pictures I could find don't illustrate that very well and I can't seem to get AutoCad to draw a foil shape very well so I'm at a loss to be able to draw it myself.

Isn't this an extremely complicated rudder for a 30 foot boat? What ever happened to K.I.S.S.?

[knottybuoyz]

Originally Posted by 44'cruisingcat

Isn't this an extremely complicated rudder for a 30 foot boat? What ever happened to K.I.S.S.?

Somethin' new to try. If it don't work no biggie! Besides I've never done anything "Simply" in my entire life Cat! Learned all my lessons the hard way!

[Alan Wheeler]

Autocad can do it. But it has been too many years since I have played with AC so I can't tell you how.
When I desinged my rudder, I drew it out on a gridded drawing paper. It was simple to do in the end and I then transfered the outline to a metal template and used that for my cutting template.

[knottybuoyz]

Originally Posted by Alan Wheeler

Autocad can do it. But it has been too many years since I have played with AC so I can't tell you how.
When I desinged my rudder, I drew it out on a gridded drawing paper. It was simple to do in the end and I then transfered the outline to a metal template and used that for my cutting template.

Gonna draw it out on MDF tomorrow Wheels. Just riggin' up a foam hot wire cutter to cut the foam. I'll post pics. Sometimes I get out the ole' drafting kit to get things right.

[Alan Wheeler]

There is one other way. Cut out the template for a top and bottom end cap. Then wrap a very bendy ply around the ends so as you are making a mould to pour foam into. It only needs to be a foot deep or so. What ever is comfortable to work with. Prewax the bendy ply and once it is together, pour in the expanding foam. Once it is set, take the ply off, pull out the foam core and repeat till you have enough to glue together to make up the height of the rudder you want.
Although in saying all that, my rudder was 8ft high. I imagine yours is only 2ft or so.

[delmarrey]

Originally Posted by Alan Wheeler

Prewax the bendy ply and once it is together, pour in the expanding foam. Once it is set, take the ply off, pull out the foam core and repeat till you have enough to glue together to make up the height of the rudder you want.

Will resin stick to the wax left on the foam? Or is there some way to remove wax????

[Alan Wheeler]

Wax won't stick to the foam. Plus is you are at all concerned, you can give the foam surface a quick sand to ruffen it up and ensure some cells are open so the resin has a greater surface area to bind to.

[knottybuoyz]

With the Cannuck loonie being on par with the US greenback I've been drawn back to the Bayliner 3288's on yachtworld and boats dot com. Prices for these boats are (appear) to be good bargains. A '92 3288 here in Canada are listed at over $110K and the identical boat in the US are hovering around $70K.

I'm being drawn to the dark side!

[clausont]

This is just what I was looking for - I would have bnought2, but it has ended now. I will email them and ask if they have any more.

Originally Posted by knottybuoyz

We picked up 4 Lewmar portlights off of e-Bay. Item #230111692976 for $59US each. West Marine lists similar size for $240US. Have been scanning e-Bay looking for stuff we'll need that are bargains when we stumbled across these. They're good quality. They've got 6 left and started with 100 a couple of months ago.

[knottybuoyz]

Originally Posted by clausont

This is just what I was looking for - I would have bnought2, but it has ended now. I will email them and ask if they have any more.

Appears they're all gone. Note on listing says "The seller ended this listing early because the item is no longer available for sale."

Del must of gotten the last two.

[clausont]

Oh, well. There will be more another day. I will keep looking. The old ones in my boat are pretty sunburned and need replaced.

[knottybuoyz]

Originally Posted by clausont

Oh, well. There will be more another day. I will keep looking. The old ones in my boat are pretty sunburned and need replaced.

Here's a list of all the E-Bay marine suppliers.

eBay Canada Stores - Boat Parts, Parts Accessories, Automotive, Accessories Gear at discount prices

Great Lakes Skipper is a good one but you gotta be right there when the deals pop up. If I run across any more I'll let you know.