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Now the fun begins!!!!! 3D

Posted by MikeInBoise 
Now the fun begins!!!!! 3D
November 28, 2015 11:28PM
Compare away! I am having a freaking blast being able to literally stick one boat in or on top of another! Here they are lined up side by side:



Re: Now the fun begins!!!!! 3D
November 29, 2015 01:29AM
Looks a lot like the boat I'm working on. I've got the side panels taken off the form, so I can dish chine edges out.


But I want to do some modeling first. Dishing out the chine is the first irreversible step. And I'm not ready yet.


There's nothing more fun than designing and building a new boat.
Re: Now the fun begins!!!!! 3D
November 29, 2015 07:24AM
I figured out how to turn perspective of which is a lot better for comparison. This is all I got for a while.... enjoy!!










Re: Now the fun begins!!!!! 3D
November 29, 2015 07:27AM
shooot. I should have kept all the dorys in the same order. I might re-do.
Re: Now the fun begins!!!!! 3D
November 29, 2015 12:42PM
I've got 2-3 days of photography left, before I get some free time. I'm trying to finance a trip to the Bahamas. It ain't cheap.

Then I'm going to get up early and spend a whole day with FreeShip. What you've done so far is spectacular Mike.

You might want to make a post, at some point, showing how to invoke the program with the right input file (already made by you), with a few additional paragraphs about how to manipulate measurements and coordinates to, let's say alter a side angle or a bottom width.

I'll work on this too. I'd like to eventually create a free, open source section of this website on 3D hull design software.
Re: Now the fun begins!!!!! 3D
November 29, 2015 04:07PM
Wonderful, wonderful,wonderful! This is a great exercise and tool. Thanks for sharing your work Mike. Sandy I look forward to the open source section on 3-D modeling.

Rick N
Re: Now the fun begins!!!!! 3D
December 01, 2015 09:35PM
Awesome! Thanks for sharing this work.

The Big Honkey is interesting. I'll be trying out the test feature on this forum to learn some more.......
Re: Now the fun begins!!!!! 3D
December 07, 2015 02:12AM
Nice work Mike, It a great example for people who don't have any idea of the different hull shapes, thanks for taking the time to post those images.
Re: Now the fun begins!!!!! 3D
December 07, 2015 05:21AM
Thanks for the compliments. All of you have shared so much with me. I appreciate what we have here with Sandy.
-Mike
Re: Now the fun begins!!!!! 3D
November 06, 2016 05:08PM
So now that this 3D modeling thread has had some time to gestate, has anybody created the perfect hull design yet? I'm kidding of course, but only halfway.
This comparison is a great tool for someone like me (inexperienced) to compare different designs without buying plans for each one. More than that, I would imagine that it allows someone that IS experienced to refine the classics and improve on existing designs..."standing on the shoulders of giants" as they say.
...and that is what I'm hoping to hear more about. Sorry if it is stretching the relativity to an old thread, forum etiquette is not my strong suit, but I'm hoping to start a new build and looking for advice, feedback, and eventually plans for a decked or semi decked whitewater boat. Wider than the Briggs, maybe even wider than a "wide Briggs), more symmetrical than the HD. Good carrying capacity, but without the flat spot of the Briggs as I'll still want to be able to turn the boat in rocky western rivers.
I have GC trip in about a year but will generally be running rivers like Lodore, Deso, Westwater, and flat water or fishing stretches like the upper green and snake - usually with my family.
It may justify a new thread to really get into the specifics but I'm really interested in what I've read about Sandy's new project, and would love to hear more about similar design evolution in hopes of honing in on a modified design that I can build.
Thanks for any and all advice and input. More to come...
EH.
Re: Now the fun begins!!!!! 3D
November 06, 2016 07:38PM
RE> "updated boat"

I've posted this photo before. This was last Fall I think. I've been out of the shop for over a half a year because of two eye surgeries. All that is behind me now. Get new glasses in a about two weeks. The photo below is not the boat itself. That's just a cheap plug made out of AC plywood, on which the real boat will be built.

This boat is made from a 4x18 panel for the sides. It is symmetrical so it will carry as much weight in the rear as the front. The middle (temporary) frame is 64" inches wide, which makes the finished boat close to 66" inches. The bottom and 8" inches up the side will be fiberglass over 3/4" inch Plascore. With lots of glass. I'm not worrying a bit about weight.

Above that will be Meranti Hydrotech. 3/8" on the sides and 1/2" for the deck. With no ribs, no frames. This is an experimental boat so I'm changing my mind about details every few days. I just glued up the 4x18x3/8 side panel together a half an hour ago. I think I will glass the outside of the side panels but not the inside. Same with the deck. For it will skin the underside with glass but leave the top side bare. And oil it, the way AJ does for his fleet of framed boats. This boat will have no ribs. It will have a 6 to 8" inch 1/2" plywood ledge top gunwale. The deck will bolt down onto that, squashing a 1/2" thick closed cell foam gasket as it goes.

The hull will be put together with torx screws, laminated ash fastening strips (between side panels and ledge top gunwale) and butyl caulk. So it can come apart and go back together again like an erector set.

The sides will be bolted to the 3/4" thick bottom with a thick bead of roofer's butyl caulk, which is wildy water proof but has no bonding strength. Every part of this boat will be removable, so anything and everything can be replaced if broken. The top edge of the 8" Plascore sides.....8" up from the chine, will need to have the honeycomb core filled with microballoons at each bolting point, so bolting the side panels onto the bottom will not collapse the soft honeycomb core.

There is no flat spot per se but the middle has not much rocker. Two feet either side of the middle (temporary) rib former the boat the frames are 62" inches wide instead of 64. The middle is not dead flat but almost. Out at the ends there is a lot of rocker. The boat has a lot of side flare too, a full 30 degrees off vertical. To keep the rocker profile under control with that much side flare I had to dish out the chine edge a full 4" inches in the middle.

Dishing out the chine has the net effect of reducing side height 4" inches at the oarlock position. But these side panels will be bolted on to a fiberglass bottom and sides a good 5" to 6" inches up from the chine. So no net side height will be lost.

The fiberglass bottom with ribless wood top is an experiment. We'll see how it goes. The hull shape is an experiment too--symmetrical with lots of rocker at the ends but not much rocker in the middle. And it is extra extra wide. I'm more uneasy about the take-apart wooden top than the hull shape. It's all speculation at this point and I've already had a bunch of nay-sayers. I'm pretty confident they'll all be eating crow eventually. ;=)) I've been making boats for a long time and I am very confident about this hull shape.

I've rowed the original narrow Briggs and a Susie Two and I didn't like either one. They're so long and narrow they don't have much buoyancy so they sink down into the water a lot, which makes them very hard to turn. Wider is better. The original 15x48 McKenzie boats scaled up to 17' feet long have a 54" inch bottom. That's what the "Wide Briggs" is: 54". But the wide Briggs is 18' feet long isn't it? Made from 19' foot side panels? It's still a long narrow boat.

This is a 17' footer 66" inches wide. A full 12" inches wider than the wide Briggs. It has a lot of bottom width right up close to the front too, so it will ride up onto standing waves more than slicing into them. I've been told that's bad..............but I don't believe it. Not for a minute. Wider and more buoyant is more better.








Re: Now the fun begins!!!!! 3D
November 06, 2016 07:58PM
Mike built a Honky Dory with a 6" inch 3/8" ledge top gunwale last year. MIke reported it did not make his boat completely stiff.

That surprised me but the last ledge top gunwale boat I made was my lake boat, which I use with a 20hp outboard, so it has little rocker. The HD has a lot more rocker, which puts a lot more torque on the boat shape.

I'll build this one with an 8" ledge top 1/2" inch thick. We'll see. This one is not an open boat. It will be decked. So flex won't be an issue.

Ah. One final detail. The Briggs and all other decked boats I've seen are a bit like a framed boat with a deck whittled in between the frames, six inches or so down from a traditional double strip gunwale.

This boat will have a ledge top gunwale with a bent deck that bolts right down onto the ledge top. The Briggs and all other such boats have the deck 6 to 10" inches down from gunwale edge, which makes a huge receptacle for water to fill when you crash into a wave or a hole. I've seen photos of half-submerged dories with 300 or 400 pounds of water trapped on the top of the boat for a few seconds, with each new face shot.


This boat will have the deck fastened flush to the top side edge, so there is no such full length receptacle to fill with water. I'm also going to bend over backwards to make the passenger and rower's foot wells as minimal as comfortably possible. I want this boat to be easily turned. At all times.

It's going to be a fun project.

I tried that software, runs fine on my linux box with wine (windows emulation software). But I still like to design full scale with cheap side panels made out of AC plywood and adjustable ribs that spline in the middle and hinge at the corners. When I look at a computer screen I just don't know wtf I'm looking at. When I look at it full scale I have more confidence. I'm a retired programmer who even wrote a bunch of 3D (microscope) imaging software. So I'm not intimidated by software. I just like full size more better. For designing boats anyway.



Re: Now the fun begins!!!!! 3D
November 08, 2016 08:05PM
Sandy Wrote:
-------------------------------------------------------
> Mike built a Honky Dory with a 6" inch 3/8" ledge
> top gunwale last year. MIke reported it did not
> make his boat completely stiff.
>

Eeeck!! I don't remember stating that. Was I drunk? Did I miss-type? Now that I have had that boat out 5-6 times I can affirm it is stiff, completely stiff. It is stout. I Love it!! I have fished 4 dudes no problem.

-Mike
Re: Now the fun begins!!!!! 3D
November 08, 2016 10:42PM
Cool. Maybe I'm misremembering. Perhaps I should have been a politician?
Re: Now the fun begins!!!!! 3D
November 09, 2016 04:10AM
I'm the one who reported it!
Indeed, it is true. I built the ledge top on Mike's boat and the boat did flex a little before additional supporting elements were added to the hull. It's because a long t-shape section IS NOT completely rigid when lateral forces are applied. The top will tend to warp a little to allow some movement. But, that is fine for his design. I'm NOT saying that the flexing indicates some sort of bad design!!! I love the ledge top, it's comfortable, functional and looks great. Just don't expect to put one on your boat, then go happily rowing in a fold up chair or some other contraption bolted only to the floor.

Like Mike said, the boat is REALLY stiff NOW. The REAL stiffness came from the awesome wide inboard sections that we added below the gunwale. Look at a picture; I'm talking about the sections that have the cup-holder holes, that mount the seat and the cooler, that hold trays of flies and drinks, that people can sit or stand on, etc. etc. etc. They also happen to make the boat really really rigid.

I can't figure out how to make an image show up on this thing. Here's the link. Mike's Boat





Re: Now the fun begins!!!!! 3D
November 13, 2016 08:25PM
Does anybody have opinions or experience with a traditional 17x54 vs a wide Briggs vs a scaled up honky? Can you dish the chine of the Briggs less than normal in order to get rid of the flat spot? What other mods would you (anybody) make to improve the other hull shapes? ...or is it best to stick with the proven designs even though they each have weaknesses?
The only hard hull boat I've rowed for more than a day is a double end McKenzie that is 14'6" stem to stern. I love it except that it is too small for multi day whitewater trips the way I pack. It was also a little squirrelly in big white water, I find myself focusing more on keeping from spinning each time I hit a wave than I do on keeping a true line through the rapid.
Any feedback to help me decide on a hull shape will be greatly appreciated.
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