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PostPosted: Wed Oct 16, 2013 1:27 pm 
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Actually the locktite will help with galvanic corrosion between the stainless and aluminum. I typically clear coat all the aluminum once completed, this also helps on the corrosion.
Bob


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PostPosted: Fri Oct 18, 2013 10:43 am 
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Not the best artist in the world. Can you tell I'm busy at work?

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PostPosted: Fri Oct 18, 2013 1:19 pm 
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DM06:
It looks like you have the all the stresses equalized with your tension lines. The Nylon strap on the front is what holds the bow sprit down. Once you sew it up (a hot glue gun will also likely work fine to hold the nylon webbing together (Per Tom Kirkman)) the best way is to pull it tight (toward the back) before drilling the holes in the 3/4 sq braces that attach to the front AKA bar. The bars are what prevent the strap from coming loose (sliding forward). and transfers all the forward/rear and lifting force into the strongest point on the boat via leverage(the front mast holder/ AKA bars). When done you should be able to lift the front of the boat by the bow sprit. The lower tension line is to prevent the front of the bow sprit from tilting down (holds the rear support brace against the hull). Again all force is transferred back to the AKA bar by the 3/4 sq bars). Since the bow sprit is a triangle shape, any side to side force transferred back to the strongest structure on the boat (the Mast assembly/AKA bar)

The middle tension line is adjustable and helps keep tension on the nylon strap which can work loose over time. I used spectra line and trapped the end under screws (just like the adjustable tension lines on the rudder). Basically you just pull the tension line tight, then tighten the screw, just like you tighten the rudder lines.

Good luck
Bob


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PostPosted: Fri Oct 18, 2013 2:18 pm 
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You think the strap from an infant seat seatbelt would be strong enough?

Also, I was thinking of using turnbuckles to keep the lines tight. Even though it's a freshwater boat so far those things like to rust though...


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PostPosted: Fri Oct 18, 2013 9:12 pm 
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Dm06:
I'm sure any type 1 inch strap will work, even a cheap strap is probably ten times stronger than is needed.

Even if you just pull the lines tight and tie knots in them it will work. Turnbuckles will also work.
Bob


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PostPosted: Fri Oct 18, 2013 9:35 pm 
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DM06 wrote:
You think the strap from an infant seat seatbelt would be strong enough?
It depends DM06 - Is the kid a strong swimmer? :mrgreen:


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PostPosted: Sat Oct 19, 2013 9:44 am 
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hate to throw a curved ball, but I am considering the same fixing solution for the bowsprit as I did for my outboard. installing to yackattack bolt through tracks with the full back and fixing whatever I come up with to that.

I have so many over my boats that i don't have a problem drilling some more holes

CC

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PostPosted: Sat Oct 19, 2013 1:22 pm 
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A little mock up of my idea. One decision I'm not sure of is whether to make the 3/4 tubing going from the bow back to the front crossbar one piece or two. If two I think I would overlap them a bit and bolt them together with a horizontal bolt for good measure. Not sure if one piece would be more desirable than 2.

The pictures show it set up as one piece.

One downside to this, if I'm using the big box hardware stores for supplies, is that they only make 3ft, 4ft and 6 ft lengths. One bar would be 57". That means I would have to buy 3 (including the other side and the sprit itself, and would have two 15" and one 29" leftover. Seems a waste.

Please excuse the messy garage.

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PostPosted: Sat Oct 19, 2013 1:27 pm 
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I think either way I do it I'd need 3 6' pieces...


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PostPosted: Sat Oct 19, 2013 3:05 pm 
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Chopcat:
I've been thinking about those yakattack rail systems since I saw yours for your motor mount, thinking of some way I can use one on my next project "whatever that may be, none planned right now". ( I still plan to make a motor mount like yours, once mine wears out (still going strong after 3 1/2 yrs).
I have still yet to drill any holes or modify any of my kayaks (the kayak itself), everything I always add is removable and can be taken off without harm to the boat (for if I ever want to sell it I guess), It's probably stupid and a lot more work for me.
Bob


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PostPosted: Sat Oct 19, 2013 3:09 pm 
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DM06:
I would have made it out of Aluminum instead of cardboard :lol: :lol:

Hey where in the Chicago area are you, I spent most of my life up in the Chicago area ( around Rockford), we moved down here to Florida in 2007, all my kids and grandkids are still up there.
Bob


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PostPosted: Sat Oct 19, 2013 4:36 pm 
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Aluminum? Ohhhhhh, that'll jack the price of this project way up. You sure I can't use cardboard?

I grew up in Downers Grove, went to high school in Rockford. Living in San Antonio now. Whereabouts were you? You're an engineer no? You work for ingersol up there? Raytheon?

Would 1 piece be stronger than 2?

What type metal do you suggest for the attaching hardware?


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PostPosted: Sun Oct 20, 2013 3:59 pm 
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DM06:
I lived in a small town called Roscoe right on the Wisconsin/Illinois border just north of Rockford for 30 yrs, before moving down to Florida in 2007.

Yea guilty I'm an Engineer. I own my own Industrial Design company (my day job), basically I sit in my pool all day designing/inventing stuff. Sailing and playing around with my Hobie, and Scuba diving is my hobby and exercise program on the weekends. My sailing hobby has nothing to do with the next generation laptops/servers, next generation explosive oil field perforation systems, figuring out how to take a skin cell and turn it into an ear, and nothing to do with the next generation DNA sequencing systems, electronic heart monitors, or blood bypass systems, and especially nothing to do with the current MIRV systems (thus the name Fusioneng, not too proud of that one LOL). All current projects that I don't even want to think about when I'm out on the water.

I don't think it's a straight line from the front AKA thru the rear bow sprit brace, and then up to the tip of the bow, so a one piece solution might be difficult. The front short sections (on the outsides) don't have to be that rectangular tubing, you could get by with 1/8 x 3/4 flat aluminum (you may need to twist/bend it slightly), it might end up a little easier and cheaper to build using flat stock.
Of course you could eliminate that back brace piece of the bow sprit altogether if you like (might make it easier to make). CaptnChaos's design and Hobie's design with their original bow brace design for the TI (used in the 2011 EC challenge race by Hobies Chief Engineer) both just had just two pieces of rectangular tubing going all the way to the bow, screwed down to a plate on the tip of the bow, thus eliminating that whole back brace thing I did in my design (probably simpler in the long run). My only reason for designing a complete truss structure was to spread out the stress upon the entire bow to a larger area, and allow attachment without attaching to the lifting lug in any way, It's probably over designed but nobody had done anything like it before, so I designed it easy for me to make in my garage in a weekend with materials I had on hand in the garage at the time ( ie... the 3ft pultrusion, and the aluminum stock I had on hand). I only made the thing to try it out quickly to see if it worked, then planned to design something later that was engineered properly, more substantial and correct later on. To my complete surprise it worked great and has held up all this time with no issues (way over 5000 hard sailing miles to date) "Who knew" LOL. Same with the Roto furling mast topper, it's was just something I threw together in an afternoon with stuff I had laying around just to try out, again 'who knew' it was going to work so well and last so long with no issues at all. I'm still running all the same stuff, with just a couple small minor improvements, and am out every weekend just sailing and enjoying my hobby. Really no need to over think it, just build it, I'm sure whatever you build will work just fine.

I just get stainless steel screws nuts and bolts from either Lowes or Home depot.

Hope this helps
Bob


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PostPosted: Sun Oct 20, 2013 6:23 pm 
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Ahhh yes, I'm familiar with Rosco. Small world it is.

I'm not sure I'm following you when you say that it is not a straight shot from bow to aka. If one was to follow the outline of the hull I'm sure it wouldn't be. And it will not meet the aka bar at a 90 degree angle. But for discussion sake, does it have to do either? The angle at the bar did not seem too far off 90 degrees, but that could have been because the cardboard was not straight. Would a straight shot mean that I would not be able to attach the aluminum to the aft most "wing" due to the shape of the hull?

I think doing a run of two, with the front being flat aluminum would cut down the amount of tubing to two 6 ft lengths.... But then again, I'm all about over engineering when it comes to hobbies. Nothing kills a day, or worse, kills a wife's interest in sailing, than stuff breaking. Especially stuff that took away from "us time" to build. Am I right?!

I'll go back out to the garage with my bubble pipe and mull it over.


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PostPosted: Sun Oct 20, 2013 7:02 pm 
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It'd be interesting to put some pressure sensors on the cross bar/back brace connection, to see how much the bow wants to flex with this sprit on.


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