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Lessons learned and more pics...

Posted: Fri Sep 22, 2006 12:05 am
by Teeeman
Here are more pics of our boats ...

far left is a test article, really fast :)

It has a simple styro flat-bottom hull, during testing ran both with and without a rudder... and has a "Help Wanted" thin plastic sheet material used for a sail.
It ran faster with a rudder for my son, for me I liked the "no rudder" weight savings.
This little simple boat taught us weight is KING. It ran a 5' gutter over 2s faster than our (far right) Balsa and hot-glue boat with same type of sail (and thick plastic rudder).

Just for giggles I puffed HARD at the test boat (far left) and it would wreck at least half the time (no straw used, BTW)... but a couple of times it jumped (and I mean jumped!) to the other end of our 5' gutter in (we're guessing) about .5s!!!!
It is SOOOO light!
Weight is king!

The middle boat:
This is our new Black Pearl.
Thin plastic "Help Wanted" sign is the rudder, styro body (currently still unsanded, cut on a bandsaw)... sail is a print on standard weight printer paper (the Jolly Roger) with Acrylic overcoat for waterproofing (water based, applied to both sides).

We have a test article painted with Latex (water based) in the garage to see if the paint is compatible with styro (solvents are NOT!)... so far so good.. but the weight... these simple boats are so light, even paint adds significant weight to them... we are debating leaving the new Pearl as you see her...

(she is glued with Elmers, so we gotta at least apply some Acrylic clearcoat)

Note the new Pearl still has a paperclip on her sail just to hold it until the glue dries... and pieces of toothpicks in her sides to also hold the sail (as the glue dries)... these will be removed and the sail unfurled.

BTW, the pics are poorly lit (sorry)... the black painted original Pearl (the Pearl Heavy, hahahah!) is actually a catamaran, not a flat bottom... very small (1/8th or less) separation of her pontoons... too bad it doesn't show in the pics)
The other boats are true flat-bottoms.

All of the hydroplane if you hit the right with the air stream.

-Terry ... esigns.jpg ... signs2.jpg ... signs3.jpg ... signs4.jpg

Re: Lessons learned and more pics...

Posted: Fri Sep 22, 2006 8:25 am
by Down-N-Flames

Have really enjoyed your testing. We need to get busy too. Last year we made a catamaran and took second to another one that took 2 of 3 to decide the winner. No one else was even close. This year we made two classes, basically stock and modified. (Stock will be single hull but I'm making the guy that wants it define the rules. Most important is whether all the kit parts must be used and how much can they be modified in the stock class. I don't want to use the keel as that is the heavy part)

My question to you at this point is even with the lack of rules we have (I am changing that) we are expected to use the balsa. I understand without it written you boat may be legal, but I would think you would get some resistance for sure. Are there any rules you have now?


Re: Lessons learned and more pics...

Posted: Fri Sep 22, 2006 10:00 am
by Teeeman
We have rules… I wrote them.

We are also VERY loosely enforcing them…

I don’t have a copy handy, try to copy/paste them later today or tomorrow for the forum…

… I clearly gave max dimensions only, no mins…

… nothing states requirement of a keel, rudder or even a sail for that matter…

… and they clearly state alternate materials are allowed.

Since we are having a fairly low-profile race (just part of the Pack meeting, sadly we get one timed run with a stopwatch and that will be IT!)…

… we may get some grousing, but I’m not worried about DQs.

I actually like the open/modified classes. But we won’t have time to even separate our pre-builts from day-of boats (which I am still in disagreement with but lost the fight).

It is that last contention of mine and the result of our protest being a lost cause that made me a bit determined to be as competitive as possible…

BTW, our flat-bottom hulls… no separation (no “pontoons”)… would that meet “stock” class by your rules?

Do you specify a requirement to have a keel and rudder and sail?

Just learning for next year… if my son or someone else is a heads-above winner the night of the race I dare say the rules will get more attention next year from folks other than me :)


Re: Lessons learned and more pics...

Posted: Fri Sep 22, 2006 10:03 am
by Teeeman
Have weights now on the boats:

Black Pearl (Balsa boat) weighs in a portly 1.1oz

The ultralight design is tipping our scale at (eyeballing the lines) 1/8th of 1ounce!!!


The latex painted boat picked up to .25oz… so we are not going to paint.

I experimented with using a water-based Crayola marker to “paint” the boat and it looked rough… my son didn’t like it at all… so we are keeping the white styro look.

Guess our Black Pearl Ultralight will simply be called the Pearl.

Still has a Jolly Roger though!



Re: Lessons learned and more pics...

Posted: Fri Sep 22, 2006 1:15 pm
by Down-N-Flames
I am still trying to get the guy to say what the rules exactly are. I'm okay with using the piece of Balsa that came with the kit, but I was going to route it out for weight and also to catch the air with the sail. The sail would be low like you are doing. At this point he is basically calling stock "make it look like the picture" well I'm not so good with that :D

The stock rules I have seen on the internet have said more than not that the sail and wood and mask may be modified (single hull) and some say that the keel and rudder shall not be modified.

We plan to run the rudder and short sail with a standard flat bottom with a slight curve in the front. I think we will also route a cut down the middle that would act like pontoons to keep it straight without actually creating two hulls. If he comes back with making us use the other parts, I will still make them smaller.

Last year they had two catamarans and everyone else was like the picture. I really don't see too much competition, but this is his last year and would like to go out strong. I'm also the cubmaster so I would like to see him go out strong too.

The biggest advantage to the catamaran is weight followed by stability and it going straight. We ran head to head elimination (double I think). It is part of a camping weekend so we are fine with time.

Re: Lessons learned and more pics...

Posted: Fri Sep 22, 2006 2:17 pm
by Teeeman
one of our test boats was a v-grooved flat bottom: ... Boats1.jpg

we tested this and compared its stability to the flat bottom...

not much difference...

we liked the flat bottom as it floats higher up out of the water and gets up on plane easier...

but it requires a rudder for my son to have consistent good runs.

Something I didn't test...

a v-groove with no rudder...

do you have the option to go w/out a rudder? Think you already answered that (required) above...


Re: Lessons learned and more pics...

Posted: Sat Nov 04, 2006 10:29 pm
by rdeis
Our rules require stock parts.

We ran a catamaran last year with a rudder and cup sail, no keel. It was the only "not like the picture" boat, and it was a heads-above winner. And got some grumbling.

I also got asked to run the event this year. (-:

This year multi-hulls were prohibited, so we ran a very short sailed hydroplane. Sharp slope from the point of the bow to about 2/3rds back, painted with a spray shellack. I drew a little bull's eye on the back of the sail to blow at, and when he hit it the thing was off like a rocket. I think one good puff might run the whole track! He actally made pretty spectacular come-from-behind wins more than once.

Hitting just the right spot was harder than it looked, though-- He ended up second to a very nicely finished conventional design.

Several kids used curved sails with no mast, which worked well, but also required some piloting skill. Full-height cupped sails are easy to blow sideways and capsize.