RG,

If possible, I would like to know the following:

1 - Plan's prices (both versions) and royalties for serial production.
2 - Estimated construction times (hulls only and complete).
3 - Do you think the additional speed and handling difficulty of the round bilge version would scare kids away?(or parents!)
4 - Considering your answer to item 3, what version would you choose if you were to build the first boat in wood, take the molds and then (try to) build a fleet from those?

Thanks!

Luiz
I plan to get the plans out using http://www.adobe.com/products/acrobat3d/ which allows you to render, slice, measure, dimension any part of the boat in 3D as well as print it all. While Adobe say its a secure document, its anything but secure, but it should greatly assist people in visualising the bits and pieces as they build the boat. As for price, it will be free (plus the $50 for the class association). Serial production royalties will likely be on a similar basis to other boats out there, so it will be very low, but I need to check on a few things before I commit to a number. Most royalties are on a sliding scale relative to volume, volume goes up, per unit royalty comes down slightly, my intent is to have a fixed lower one based on the optimistic assumption that we will inundate the planet with this class <img src="http://www.catsailor.com/forums/images/graemlins/smile.gif" alt="" /> LOL

For the hard chine boat I'd guess 8-9 weeks would be a reasonable time and the round bilge one because its a strip planked foam build, probably another 2-3 weeks on top of that. This assumes that your just doing it in the evenings and on the weekends. If I can get someone to scarf the sheets and precut the panels like Scarecrow is proposing, then you might be able to cut the build time down by a few weeks.

The round bilge boat is only just over 1 knot faster at the top end, so I doubt that will scare anyone. As for handling, I hope it turns out like some of my other recent designs which were all pretty benign. This version btw will be more pitch resistant that the hardchine version.

As for your last question, hands down I'd do the round bilge boat because I like it more, but in trying to sell a few of these, most of the kids tend to like the hardchine one....go figure? Think the choice is up to those who like one or the other design better.

Cheers
RG

G'day Matt you'd have PM too but the computer says youre not accepting it <img src="http://www.catsailor.com/forums/images/graemlins/tongue.gif" alt="" />. I hopefully sent a message to the e-mail address in your profile yesterday. Since our clubs are not far apart ( relatively ) I'd like to have similar cats.
I already piggyback a 420 on my cat trailer so I'm hoping to get 2 youth cats on instead
regards Jeff

Hi Jeff

No email, I just had a look my correct email is the profile, tiffmatt(at)bemail(dot)com.au

I've just changed the accepting private messages, I didn't realise it was on 'no' I bought a new computer a few weeks ago, and must have done something when I logged back on.

Regards

Thanks!

Maybe that is not so suprising if you look at modern sports cars, chines are in fashion <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />







Gareth

Let's follow the trend and make them MULTI chined... <img src="http://www.catsailor.com/forums/images/graemlins/wink.gif" alt="" />

After reviewing the designs once again, it is clear (to me) that the stayed rig is unnecessarily expensive and complex. The free standing strut supported version simplify the rig, transport, assembly, storage, construction and structure. The struts are a good grab point and add safety for children. They make the evolution to a smaller or larger rig inexpensive and easy - if and when the class decides so. Mothers could even rig vinyl spray deflectors there for dryness and shade. I like them.

In the free standing rig version, if we place the gooseneck in the main beam, the sleeve could leave a gap where the struts are welded to the tube and be double velcroed around the mast below that point. This would solve the gooseneck problem and allows a small reduction in mast height.

Does it make sense to you?

What gooseneck problem are you refering to ?

Personally I would strongly prefer to have the boom above the attachment points of the push rods as then the rig can rotate fully around the mast which is very advantage (performance) when sailing deep. It also is a safety feature as any kid can let the rig weathervane completely when surprised by a squall or something.

A freehanging boom (possible with a fork at its mast end) is possible and most easy solution

Wouter

Not sure a reduction on mast height gains us much as its such a small triangle at the bottom that you gain, and that doesn't lower the COE very much. And I tend to agree with Wouter about letting the sail weathervane if required.
Also, don't see that the stayed rig is that much more complicated, but do agree that the freestanding is faster & easier to rig.
Too my surprise, most who I have talked to so far have elected to go after the stayed rig because it will allow trapezing, and these are the kids talking, not their parents who don't seem quite as sure about the whole thing. In the words of one kid.....why should I hike all day when I can trap and go "zoom"
Cheers
RG

The following attachments should give you an idea of how I think the hull jig should go together, this drawing is not yet complete....if any of you want changes, speak up.
Pic #1 the base box, made of 2x4 or 50x100mm, kiln dried so it won't warp and nice and heavy so it won't move.
Pic #2 plywood wrap, 25mm on top and 12mm on the sides
Pic #3 12x15mm cleats screwed to the box to attach the frames to
Pic #4 Frames get attached (12mm thickness)
Pic #5 Upper cleats are attached, these could actually be attached prior to attaching the frames
Pic #6 Frame beam is inserted
Pic #7 Hull in the jig

The front 3 frames that aren't attached to the base, I'll explain how that works once I get the rest of the drawing done.
The next 3 frames moving aft will be detachable and can slide aft when your ready to lift the hull off. This is required because of the tumblehome.
The rear frame is notched so you just have to sit the transom sheet in place to get it aligned correctly, all frames are notched on the outboard edge to help hold the side panels in place correctly.

Cheers
RG

Pic #2

Pic #3

Pic #4

Pic #5

Pic #6

Pic #7

BTW, forgot to mention that the frame beam has some fore & aft supports that are not shown yet so that the whole arrangement stays rigid.
Cheers
RG

I think this is extremely important feedback from your market. It would be interesting to know the ages of the kids you're getting these comments from, RG. It seems that most here have been fairly resistant to the trapeze idea, but I believe that clearly differentiating your product in the market is an important element of success. It's one thing to say "it has two hulls, two hulls are faster, you'll like it", but another for kids to actually see that there's something quite different and exciting about the experience of sailing this baby from their buddy's monohull. I understand the argument in favor of the unstayed mast, but I don't think you should ignore this issue.

You are both right. Besides Optimists, I sailed with fork type goosenecks in Penguins back in the 70's - with rotating wingmasts! It is very simple, efficient and inexpensive for small boats exactly as you say. Note that it was not possible to weathervane the Penguin due to the shrouds (unlike the Optimist), so the fork solution is ideal for the free standing rig only, not so for the stayed/trapeze rig.

Two divergent conceptual paths (trends) emerged and are being followed:

a) Simplicity oriented, with chined hulls, free standing rig, hiking straps, cheaper price. It is essentially the original F12, but I'll call it F12 One Design.

b) Performance oriented, rounded bottomed hulls, stayed rig, trapeze, normal price. It is essentially a Mini A Cat.

I guess it is ok to follow both trends until a clear winner emerges. Still, we already know that the Mini A Cat will end as a scaled down A Cat, so we could just as well follow the F12 One Design path only and in the end compare everything to a scaled down A Cat - including the class rules.

I made my own spreadsheet to rationalize the decision process and it indicates that the F12 One Design wins by a small margin, basicaly due to simplicity and costs. The other differences more or less cancel themselves. Sorry, could not upload the spreadsheet as is, just its picture.

It might not be necessary to assume that a trapeze version goes with the round hulls and higher construction skill.

I note that your spreadsheet indicates a target age range that spanning both Wouter's original target and the younger kids that others favored. Not sure if this is generally agreed by everyone else. Still interested in knowing the ages of the kids RG is talking to.

Also curious whether "one design" is still the consensus. My impression was that Chris and RG are both pursuing separate designs with the expectation that they will both fit into the box rule defined by the measurement form they put together.