Author Topic: 12-6' x 30" design tips  (Read 32042 times)

jrandy

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Re: 12-6' x 30" design tips
« Reply #15 on: June 18, 2015, 04:31:58 AM »
I am stuck on what to do with the nose and rails.
I saw some more stuff from Jimmy Lewis, wondering if I should get rid of the 'love boat' (not sure what to call it)nose and go 'simpler is better' like the one below.  I am too much the 'noob' to have experience or an opinion.

Any advice would be appreciated, I need to get back into action on this. Thanks, J

http://pushheretosavealife.com/
Be safe, have fun. -J

TallDude

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Re: 12-6' x 30" design tips
« Reply #16 on: June 18, 2015, 09:17:28 AM »
Those last two displaced noses (bows) are both common directions and each have their merits. The first board will track better, with a pronounced "V" bow, it will displace the water quickly to allow for an efficient transition to a wider board. Very common on 12'6 boards where you get to the maximum width in less length. Two draw backs to this is a developed bow wake at higher speeds, and increased foot steering or over-steering. If you have softer more rounded rails the length of the board this foot steering becomes more apparent. The 404 have a sharp "V" that transitions to hard or sharp rails to reduce foot steering. Hard rails will also create drag. 

The second board is what I would call the Craig Richmond hull. He was designing this hull for prone paddlers 20 years ago. You see this more on 14' or longer boards. Because of the increase in distance from the bow to the widest point of the board, the bow has almost no ''V" in it. You will get little to no bow wake depending on length. The rails can be softer throughout, without too much foot steering.

If you recess the deck to make a foot well, you will increase stability. If you make the mid to rear rails harder, you will increase stability, but create some drag. Rounder softer rails tend to make a board roll , feeling tippy but less drag.   
It's not overhead to me!
8'8" L-41 ST and a whole pile of boards I rarely use.

jrandy

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Re: 12-6' x 30" design tips
« Reply #17 on: June 18, 2015, 02:42:20 PM »
Talldude, thanks again for fielding my questions, I really appreciate it! -J
http://pushheretosavealife.com/
Be safe, have fun. -J

jrandy

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Re: 12-6' x 30" design tips
« Reply #18 on: June 21, 2015, 08:12:50 AM »
I cut out the recess yesterday...today if consider that I did not leave the garage until past midnight.
I was hoping to do the board without but became convinced from advice given here and on other threads that I would regret not doing it in the long run.

The process went OK.  In retrospect I wish that I had accounted for this earlier (precut stringer before glue-up and/or precut curve into scrap and glue on board) so as not to have to employ a router w/o vacuum, inducing an 'EPS winter' in the garage.  A profiler/router box like Talldude's would have helped too but I am trying not to make or buy extra large tooling right now.

What I did:
1. Drew idea on computer
2. Drew idea on rosin paper, wanted to see it full size. Painted pad areas black for kicks
3. Changed idea for hardboard template from half-circle to 90 degree w/ generous radius
4. Used 1/2" diameter x 1" deep router bit w/ top bearing to follow hardboard template, did not cut stringer. Used clamps to hold template and scraps to avoid clamp marks
5. Used half template's straight edge to rout along outside of stringer foam only
5. Cut away stringer, riding on foam, no guide, took 3 passes increasing depth each time
6. Took final depth from stringer rout and routed away foam inside curve freehand and a couple guide marks for hotwire battens
7. Attached battens w/ drywall screws to sides of blank from tips of the recess to tail of the board
8. Hotwired approx. 8' of foam 1" thick, riding on battens and stringer
9. Used 20 grit torture board to knock down hotwire whoopdy-do's

I am planning on tapering the cut from recess to the cowl a couple of inches to aid in glassing. Attaching a picture to go with the steps. -J


 
http://pushheretosavealife.com/
Be safe, have fun. -J

jrandy

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Re: 12-6' x 30" design tips
« Reply #19 on: June 21, 2015, 12:00:41 PM »
...and a couple more pics:
http://pushheretosavealife.com/
Be safe, have fun. -J

TallDude

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Re: 12-6' x 30" design tips
« Reply #20 on: June 21, 2015, 08:40:18 PM »
Just some suggestions. No need for a lot of volume and windage at the nose.

« Last Edit: June 21, 2015, 08:43:36 PM by TallDude »
It's not overhead to me!
8'8" L-41 ST and a whole pile of boards I rarely use.

Biggreen

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Re: 12-6' x 30" design tips
« Reply #21 on: June 22, 2015, 07:11:31 PM »
Man, what an undertaking! Is it as much work as it looks like from my couch? Now I see why UK Charlie built his CNC machine. Talk about having to be resourceful. Cool thread. Thanks!

jrandy

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Re: 12-6' x 30" design tips
« Reply #22 on: June 23, 2015, 07:48:58 AM »
I really appreciate the suggestions and well-wishes. It's been a lot to do but fun to do at the same time.
I am getting excited to make it look more like a board with bands, etc.
The recess is deepest at 93" from the tail, going to modify it for 'toe room' as suggested.
Last night I took a break from the board and worked on some fins.
http://pushheretosavealife.com/
Be safe, have fun. -J

jrandy

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Re: 12-6' x 30" design tips
« Reply #23 on: June 24, 2015, 08:38:09 PM »
Some pics of my misadventures in recess re-shaping. -J

1. New lines, so far so good...
2. Possible restyle of tail?
3. Left handed bevel cut runs awry!
4. White foaming PU glue, 233+ tape, and a clamp to the rescue.
5. Done for the night, will let the glue harden and smooth it out tomorrow.
http://pushheretosavealife.com/
Be safe, have fun. -J

TallDude

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Re: 12-6' x 30" design tips
« Reply #24 on: June 24, 2015, 08:58:20 PM »
Looks like it's coming along. That tail thing you got going is interesting........
It's not overhead to me!
8'8" L-41 ST and a whole pile of boards I rarely use.

PonoBill

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Re: 12-6' x 30" design tips
« Reply #25 on: June 24, 2015, 09:30:17 PM »
57' Chevy??
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

jrandy

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Re: 12-6' x 30" design tips
« Reply #26 on: June 25, 2015, 06:48:18 PM »
57' Chevy??

Chevy, Caddie, Bat-mobile...the scraps just wanted to be there...until I sacrificed them in the jaws of the clamp. Now they are in the EPS recycling bag.
http://pushheretosavealife.com/
Be safe, have fun. -J

Biggreen

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Re: 12-6' x 30" design tips
« Reply #27 on: June 25, 2015, 07:52:28 PM »
Hey I just noticed. Very clever marking gauge.

It's funny. I think one of the most valuable lessons we all learn when building and learning to build is how to fix our mistakes. I personally am getting quite adept at it. I am however, an expert at making them.

 Looking good, JR!

jrandy

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Re: 12-6' x 30" design tips
« Reply #28 on: June 26, 2015, 08:14:19 PM »
Thanks for the comments everyone, they are appreciated.
Back out in the garage tonight, I started to round the edges on the deck.
Hoping to make enough progress to glass within a week...
http://pushheretosavealife.com/
Be safe, have fun. -J

jrandy

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Re: 12-6' x 30" design tips
« Reply #29 on: June 28, 2015, 06:32:29 AM »
I have the beast flipped over on the sawhorses.
I am trying to get my head around the cutter nose in the first Jimmy Lewis pic and the markups from TallDude and I have never done such a nose before, in CAD or with tools by hand.

On the first Jimmy Lewis pic, it looks like the convex 'boof' goes back 4-5 feet to the rails and flat on the bottom and the concave cutter/keel thing is pronounced at the bow and blends in rapidly to meet up with boof and bottom.
Does this seem about right?  It all looks bigger on the screen and smaller on the stands today.

Any tips on the layout and/or execution of these details with common hand or power tools would be greatly appreciated.

Thanks, J


http://pushheretosavealife.com/
Be safe, have fun. -J

 


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