Non-foiling trimarans and catamarans - Page 3 - RC Groups
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Dec 28, 2015, 07:32 PM
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Dick L.'s Avatar
I would hope to see your further involvement in the multihull classes for the future. I think there may be some emotional aspects of the multihull design we must first cross to garner others, along, of course, with an increase in home builders. As you say, with the IOM being an almost off the shelf boat (given design and monetary considerations) the world of multihulls is like a fresh new garden, with designs and ideas waiting to be tried or built. Unfortunately, with the exception of RCSails in the far east, there isn't much available to simply "purchase". I did spend a few $$$ and picked up one of the Dragon Force 2-60's in the RG65 cm range to play with. Initial results were dismal in the dire need to completely dismantle the boat in order to seal up manufacturing holes left to run radio wires, etc. While not a big thing, it is just another issue a new sailor must deal with to have a watertight craft.

Happy New Year to you and yours for 2016.

Dick L.
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Dec 29, 2015, 07:43 AM
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glouis's Avatar
The Germans are pretty good in building and they have an active fleet of multis like the French but the French seems to have veered towards 2m over Mini40 when I started. I don't mind that my next project after I finish the restoration of my A-Class Sweet 9 is my 2m trimaran with my own plans... using styrofoam boards for building. But won't be with reverse bows ;-)

Ernst also who's in Austria (I think not sure) did great work on sharing some of his designs and building methods few years back like you do. I'm actually looking for others who did successfully build hulls in foam to see how they did theirs. I use to do a shape of the deck and bottom of the hull in wood place them on top and bottom of the block of foam and cut with a hot wire along the edge to get the vertical and horizontal lines then finish up by sanding but eye finish so not perfect but good enough. Must be ways to make hulls out of foam on their length without planking.

Here in Ireland I'm the only one with multis. I have restored and brought back my old Cobra with new rig, sails and electrics. I have a replica of Jet Services II 1.7m long (not for racing). It has a Lmast on pivot. But my next one is a 2m - been looking at plans for a while but hard to come by to see if the shapes and dimension on mine are not too off the mark.

Here is the link to my flickr album with my restored cobra https://www.flickr.com/photos/132294...57662228738419

Happy new year to you and all RC multis enthusiasts!
Last edited by glouis; Dec 29, 2015 at 07:50 AM.
Dec 29, 2015, 11:11 AM
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Dick L.'s Avatar
A former friend and mentor to me was a "Class Guy" - Mike Howell - UK .......... who, more than once, provided me with guidance, technical help, and a social comment - "Forget what he said. " - with reference to another person's posting comment or reply.

Unfortunately, Mike left us way too soon, and many of the new folks never had the chance to get to know him, his passions and his love of multihulls. May he rest in peace.

Tied to these comments are a set of lines and plugs that he was working on prior to his death. Perhaps you might have ability to be able to track down their current location - or owner. He was in the middle of building a new 2 Meter, and probably would have "binned" the plans once the new AC foilers appeared. Here in the US, I would be happy with anyone considering even the little 65M multihulls - just to get the interest going. Then promote the MultiONE class and then on to the bigger boats. Have to start somewhere.

Anyway, have attached a couple photos of Mike's ideas if they may serve of some help with your design. Also, please PM me with your email address and I will send you a series of photos provided by Jean Margail who had provided me with the lines for his Water Resist multihull boats. His designs were for foam construction, and you might see something to help with your desire to build a foam-based boat.
Last edited by Dick L.; Dec 29, 2015 at 09:03 PM.
Jan 01, 2016, 02:58 PM
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Dick L.'s Avatar
Had a chance over the past couple of days to research and work out a design for the "Economaran". Using common dimensions for the Mini40/F48 sails, I came up with this 5 panel, mainsail mock-up. One of the hulls is setting on the floor, just slightly too far aft of the main luff. (hull needs to be shifted forward to get luff tack somewhere near the location of mast base). This sail plan is still below maximum, as I did not include a jib - although the main is cut and dimensioned for a full jib. I think I may start out sailing it as a uni-rig before adding the extra horsepower. If jib is included the dimensions of the entire rig will run right around .9m2
Jan 02, 2016, 03:11 PM
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Just kicking around ideas here, but I think method to consider would be stacked foam. It would take a bit of sorcery to get the profiles just right, but a cut from 2" foam on a CNC cutter could be dirt cheap. It would also be fast to modify.
Jan 02, 2016, 05:01 PM
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Dick L.'s Avatar
I used the foam method for my first F48 back in the early 2000's when I did the Water Resist design by Jean Margail of France. Found it to be too heavy, so I wrapped with package tape and laid up a couple layers of glass. Wasn't happy with the "vertical" split of the hull when trying to add aboard trunk, so dumped the glass but still have the foam version.

With my thoughts about using foam for deck and bottom of hull and thin sheet balsa for sides, it is weight loss a new builder doesn't need to worry about.

Grandson is now in college and plans to build a CNC platform for laser and router application ( he already has a 3D Printer built and working) so I may reconsider solid foam from a CNC when he has it done. Again......trying to get new builders to try a multihull and not have to think they need Hi-tech equipment or tools to build a multi.

Thus the boat name - Economaran. !!
Jan 02, 2016, 05:19 PM
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glouis's Avatar
only a few people have access to CNC and pressure with oven bake C/F built. so the solution for a simple yet working method to build multis so i'm with you Dick.
Feb 10, 2016, 07:54 PM
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Dick L.'s Avatar
Cold weather keeps coming back, making garage work "unpleasant".

I did a mock-up of the hull with an A Class cat mainsail configuration. It is projected onto a wall, with hull sitting below. After taking photo and looking at it, I want to move the rig further aft, and possibly increase the length of the sail foot (and leech and overall sail area) The photo may be a bit out-of-focus since it is an overhead transparency projector, but it is easy to see and understand. The luff of the sail is measured to 74 inches which gives me several alternatives for a mast. Strip built wood, aluminum or carbon tube. Still toying with self-adjusting full foam battens (Foam core board with epoxy/glass covering on both sides) but not a critical issue at the moment.

Dick
Feb 11, 2016, 11:57 PM
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Hi Guy's,

A solution to glassed foam being heavy is to leave a transom open and once the glass has cured use petrol or acetone to wash the foam out. You will need a good sized hole in the ground to dispose of the very non environmently acceptable glug that runs out. I've built several IOM,s this way a lot of years ago. If you want a smooth inside wrap foam in packaging tape.

Tony
Feb 12, 2016, 09:24 AM
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Dick L.'s Avatar
Hi Tony,

the original foam hull and amas I wanted to retain for other layups, that's why I didn't remove the foam. With a marked decline in multihull interest back in early 2000's, I just shelved the hulls, cross beams and amas hoping for more interest. I can still pull them out and re-glass. Hulls are slit vertically so foam can be pulled from the glass as it is usually covered with tape. The above effort is trying to build something the average or beginner builder could do. Back then, I even experimented with foam strips laid up on a female set of templates (instead of male ones) . While it worked OK, I found I needed about double the number of hull templates to support the foam as it wasn't strong enough to support the strips between the templates.

You are correct though - gloves and large garbage bag needed if one is going to "flush" the foam out of a glass hull. Thanks for the comment.

Dick
Feb 12, 2016, 06:01 PM
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scottd9990's Avatar
Quote:
Originally Posted by disabled
Hi glouis,
reverse bow in rc scale:
Have a look here:
https://www.youtube.com/watch?v=1563...ature=youtu.be
It definitely works!
This has really sparked my interest in this type of RC Sailing. I really like this black boat in video. Is there a plan or drawings for this boat available?

Scott
Feb 12, 2016, 08:01 PM
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DLord's Avatar

MOD 40 Tri


Contact Kampai26--(Chris) on this thread on the German forum-he is the designer and builder:
http://www.rc-network.de/forum/showt...-Semiscale-Tri
Feb 12, 2016, 08:13 PM
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Dick L.'s Avatar
A couple more tri/cats and we might be able to make an argument to hold a North American Championship series - - and see if we can get enough of a turnout/attendance by including the M65, Mullti1 and Formula48/Mini40 size boats. If not enough to get a number to make up a class, we could (owners willing) run the event as a handicap (time on time). BTW although not exactly 65 cm - the Force 2-60 has been pulled in to the M65 Class and can race with the smaller class of boats. Considerations will be given to those foilers that would show up.

Might need a bit of experimenting and some local time trials to help set the initial handicaps. Won't worry about that until there is a number of un-like boats that want to race.

Dick
Feb 12, 2016, 09:36 PM
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scottd9990's Avatar
Quote:
Originally Posted by DLord
Contact Kampai26--(Chris) on this thread on the German forum-he is the designer and builder:
http://www.rc-network.de/forum/showt...-Semiscale-Tri
Thanks for the link.
Mar 25, 2016, 04:54 AM
Registered User

weight reduction


Hello Dick L,

About your pictures of ama's. I myself made a small trimaran (80 cm) but it is to heavy. It weights about 1600 gram (rc stuff and batteries included). My vaka and ama's are made from pvc pipe (smallest thickness) and have a diameter of 6 cm. Vaka's weight is about 350 gram. Ama's weight is about 280 gram.
My question: what weight is one ama in you pictures.
Other question: my batteries (4 x 1,5 V ) weigh about 100 gram and my two servo's together 90 grams, my sails and mast weigh about 130 gram. Height mast is about 1 meter.
Do you have any clues on how to reduce weight ??


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