Radio Controlled Yacht

[Kiwi Phil]

Has anyone here done or had experience with
1. Roto-molding (rotational molding), without heat
2. Surface Casting http://www.freemansupply.com/video.htm
3. fibreglass-ing

My kid Hayden and me have Wee Nip Radio C. Yachts.
As an interest, I would like to make one out of laminate, fibreglass or plastic.
I have no experience, but been reading up, and will have a go if I think I can succeed.

What has me thinking along these lines is, the 1st boat Hayden had was this mass produced one;
http://www.modelflight.com.au/rc_model_boats/century_750.htm
There are many similar variations, all are complex in their mechanics, (which easily fail), and because they are a scaled down version of a really great yacht, they are hopeless sailing, as you can?t scale the weather to match.
They are tall so need a big wagon. Good idea, look absolutely brilliant, but a toy.

That is how we have ended up in a Wee Nip class club.
These things go really well, mechanics are over simple, 110% reliable, and they will fit in the boot, and take all of 1 min to take apart or assemble for sailing.
http://sites.google.com/site/theweenip/
In pics 1 and 2 you will see what they are like.
The videos are a bit tame compared to what we do at our meetings.
They will sail the butt of the other brands.
Our boats are better set up than these. I will try and get pictures of ours later.

OK?so the 1st type (Centuary) are one-piece plastic boats with no seams or joints between hull and deck (keel bolts on)?..so would I be correct in guessing they are roto-molded.
Does anyone know?
Has anyone done rotomolding. It?s on youtube?.some DIY, but nothing like a model yacht.

Then comes Surface casting (2 above).
(Halfway down that page, just above section 3 is a video).Has anyone here ever done this?
Somehow it does not seem suitable to this application.

Last comes straight out fibreglassing, which I want to avoid if possible.

Has anyone ever done anything like this??

Last point. I had heard that plastic canoes are one piece and quicker and easier to make than fibreglass. Would they be rotomolded.?

Cheers
Phillip

 

[marlboro180]

Re: Radio Controlled Yacht

Never done rotomolding, but scratch built a couple glass r/c nitro boats. The glass one turned out kinda heavy, and hard to make look good due to my being a novice.

The outboard tunnel I built out of laminate plywood was fun and light. Easier to make look good ( for me) and went like crazy.... Easy construction too.

Looks like fun sailing though!

 

[CN Spots]

Re: Radio Controlled Yacht

I saw them making a rotomolded kayak on How It's Made a while back but it had to be heated in a giant oven. Most of the rc boats that I've seen are injection molded. Makes sense for mass production as they can make the hull and the cap separately and fuse them together w/either glue or ultrasonic welding after the internal components have been installed. I have a large rc airboat made (by a commercial manufacturer) using this process. It has a ridge where the two parts were fused together, but it's solid, no visible gap.

Hard to tell how they made them without seeing one up close. It might have even been blow molded, like a soda bottle.

 

[tommays]

Re: Radio Controlled Yacht

I built a Dumas 30" Star from a wood kit LOT of work but no special skills required low cost compared to a fiberglass hull kit


IMHP if your just building one boat its the way to go as there is no tooling molds ect

30" is on the small side to do much real world use 45" hulls seem go out and take it much better

Things like carbon tubes for masts are pretty easy to find as there used so much in kites and things lile kevlar fishing line make good rigging

Most of the easy build boats just dont sail well and are a waste

 

[Kiwi Phil]

Re: Radio Controlled Yacht

Thanks all.
I have not given the idea away.
Met with a bloke last week who makes 'objects' out of plastic....he was really helpful. Got to go back late this week...he is having a think.....his 2nd thoughts were;

Have a specialist with CAD and router who will;

Glue MDF board together till it is height of hull, and have router cut out the inside, leaving a female mold.
Then do same again with MDF, and have router trim outside leaving a male, BUT, it is (in your measurements) approx 1/8th smaller.

Drop it in-side female and hinge at back so you can swing up-out and back.

You then heat a sheet of plastic under the 1m sq element, drape it over the female, and swing the male in/down, then lock in down.

He is making what he calls Jockey Hub Caps out of perspex (there are the sulkeys that trotting and harness horses tow with the rider in) .....The hub caps replace the spokes on the wheels & eliminate a lot of injuries apparently. Bit like the racing bike wheels you sometimes see. His are clear though.

He tells me the blow-mold is the best for me, but the set up costs are prohibitive.
Rotomold would be good too but set-up costs high (now got plastics (2 part) that once mixed will set without heat).

Will keep you posted.
Cheers
Phillip