Forums > Land Yacht Sailing Construction

Class3

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Created by aus230 > 9 months ago, 15 Apr 2013
aus230
WA, 1659 posts
20 May 2013 8:58PM
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Pretty hard to do on the strip built, as I have made it on the one whale back so they are a mirror image of each other. But I will be doing that on the foam mast.(after I catch up with you.)

What is the benefit of a tapered mast some class3 have one some do not. (same for ice yachts)

Thanks for the info on the ratchet/winch)

landyacht
WA, 5921 posts
20 May 2013 9:04PM
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Select to expand quote
aus230 said..

Pretty hard to do on the strip built, as I have made it on the one whale back so they are a mirror image of each other. But I will be doing that on the foam mast.(after I catch up with you.)

What is the benefit of a tapered mast some class3 have one some do not. (same for ice yachts)

Thanks for the info on the ratchet/winch)


I would assume it is about weight and the ratio of the cord lengths at the top of the wing.
as it was explained to me a mold is made with a taper in both ends, then 1 side is made using the taper at 1 end, and the other side made using the taper on the other end ,
makes sense to me

aus230
WA, 1659 posts
23 May 2013 10:25AM
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Interesting read. British Land sailor
http://www.bfslyc.org.uk/landsailor/Edition%2064.pdf

Fitted the back retainer for the spring board(think that is what it is called) I will give it a layer of glass.



Internal's of the wing mast in place(hope this is right if it breaks it is not) close the two halves later today.


This is the strip built wing that I tried to duplicate.


aus230
WA, 1659 posts
25 May 2013 4:25PM
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Getting there.
The wing mast has turned out alright, can not to finish it until I get a sail(trailing edge and track to be fitted then glass the outside of the mast.)

I can now concentrate on the body internals.(the shed is now clean)


aus230
WA, 1659 posts
25 May 2013 8:40PM
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Guess I will have to start thinking about the rear plank. What are the most suitable wheels, I was thinking about using a couple of 15" get me home spare wheels. Also what type of hubs do I use, Same as class5 but made on 25mm axles or would light car/trailor hubs be better. Once again have not seen them on a yacht.

SJK
43 posts
26 May 2013 7:10PM
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Hey Vic,

At almost all our yachts we use ash wood for the rear plank. In addition we use the hub of a trailer and add car wheels of around 13" that aren't really wide. Preferably we use balloon tires without tread. I know that at de Panne, Belgium, where we mostly sail, almost all bigger yachts also use balloon tires without any tread and the wheels are about the same size as ours (thus 13"). I'm not sure if they also use the hubs of a trailer, but I believe I have seen some yachts that use hubs similar as at your class 5. However, I have absolutely no idea which diameter they use for their hub.


landyacht
WA, 5921 posts
26 May 2013 7:42PM
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25mm would be fine,I reckon if youve got a lathe to make a hub and some 15" motorcycle rims or some of those get me home rims it will be fine . definitely 15" then you can run car or M/c tyres.
I would make a hub , fit it with 50x25 precision ball bearings and seals, cut the centre out of the car rims and weld in some round tube spokes. very common kind of wheel that Ive seen in Europe. the smooth tyres they use come from the US ,are called smoothies and are very light.
the rims they use are Renault 2CV and rather rare in Aus. the tyres they use before smoothies were michelin 15x5 's which are really light, but very hard to get now. HOWEVER, a couple of years ago when the 2CV club came through Kalgoorlie , I got the names of alternative tyres off some cars , and my tyre man in Boulder was able to get them overnight at only $80 each. they will last forever
the beauty of 15x5 rims is that you can also fit big MC cruiser tyres which work really well on our hard surfaces

SJK
43 posts
26 May 2013 7:48PM
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In addition, have you considered building a sail raising system at your mast?



If you place a pulley at the top of the mast and put a steel cable on it, with on the other end a rope (see picture), you can easily raise your sail without having to put the whole yacht on its side.
If you are interested, I can take some better pictures of the system.

Stephan

aus230
WA, 1659 posts
26 May 2013 8:32PM
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It was mentioned to me by Paul the other day. I can still install one as I have not closed the trailing edge of the mast yet(Have not installed the track as I want to get the sail first). Sure would like any info on pics as they will help me and be info for others.
Cheers
Vic

kiwi307
488 posts
29 May 2013 4:46AM
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A few answers while I have been away!
Vic, make sure that back end fitting for the runner plank is strong, it's a common point of failure.
Wheels, 15" as narrow as you can for beaches, 125 /15 are as wide as you want, 135 is OK. Talk to the Citroen guys on the Aussiefrogs forum. I have always used rims 3.5" wide. DO NOT use space savers, they will kill your performance. Motorcycle tyres are worse still.
I have never used a halyard (sail raising device) on any of my class 3s, tip the yacht over, easy, safe and KISS.
Why are wheels upright? Cos the plank (rear axle) flexes and applies camber. The photo with upright wheels is unloaded. You don't need to have any tension on the stays when static rigged, axle flex will change it all anyway.
Beautiful stripp job Vic. I see the mast is being done inside first, sort of inside out. This is much easier.

aus230
WA, 1659 posts
30 May 2013 2:56PM
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Thanks Guys
Just about ready to join the two halves. Just added a vertical brace for mast support, I will add steering when both halves are joined plenty of room for that





aus230
WA, 1659 posts
30 May 2013 7:19PM
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Would love to see a fleet like this here. Never happen I guess

cisco
QLD, 12321 posts
30 May 2013 11:23PM
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Select to expand quote
aus230 said..



Thanks Guys
Just about ready to join the two halves. Just added a vertical brace for mast support, I will add steering when both halves are joined plenty of room for that







Dammit Vic. Is there anything you DON"T have in your shed?? Shelving, cupboards, benches, lathe and drill press, fret saw, pot belly stove, BBQ just out the door and a thinking chair with one caster wheel missing so when you lean back and go to sleep it stays put.

Oh, I forgot to mention space to do stuff.

aus230
WA, 1659 posts
1 Jun 2013 10:48AM
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Both halves joined.

Both halves mated and held together with fiberglass reinforced tape. Then run a 2" strip of fiberglass tape soaked in resin down the joints on the inside of the hull.(Had to role up the tape after it was soaked in resin. Then used a long stick to unroll it down the inside joins)



Remove the fiberglass tape and fair the joints, then I laid 1" strip of glass down the outside joint, followed by 2x2" over lapping glass tape down the joint.

lachlan3556
VIC, 1066 posts
1 Jun 2013 1:18PM
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Beautiful!!!

greenE
47 posts
1 Jun 2013 2:59PM
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absolute work of art,inspiring indeed ;-)

SJK
43 posts
1 Jun 2013 5:59PM
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Looks great! But what is the white plate at the top of the yacht? Is that for the mast mount? How are you planning to mount the mast on it?

(The more detailed pictures of the sail raising system will still come, but I haven't had time yet to make them)

aus230
WA, 1659 posts
1 Jun 2013 6:59PM
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Yes it is the mast mount, The white stuff is fairing gook. I will fair it all in when I go over the hull before painting. The plate takes the mast pin but allows for 120mm of adjustment forward and back. Thanks to Chris from the York Land Yacht Club for helping me understand this part.

Mast plate and pin similar to pics (my plate is 110mm long to allow adjustment forward and back from a center point 1.5m in front of center of rear axle


SJK
43 posts
1 Jun 2013 7:08PM
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Ah, ok. Then the mast mount is exactly the way I know it, but I have never seen it adjustable. It looks like a good system, though I do not know how useful it is to be able to adjust it only 120 mm. It seems to be only a small adjustment. But then again, I have never tried adjusting the mast position, so actually I don't know how it influences the sailing.

aus230
WA, 1659 posts
1 Jun 2013 7:25PM
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It is about the same adjustment as I have on my class5, even a couple of degrees at the bottom has a large movement forward and back at the top of the mast. It sure helps with the tuning on the five so I should imagine it will help balance the yacht.(bugged if I know,seems like a good idea)

Another question. The rear plank on the class3, any one know how thick,how wide and how much taper should I be looking for. Any help and pic's would be appreciated.

SJK
43 posts
1 Jun 2013 7:30PM
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Well, it surely will not influence the yacht negatively, so from that point of view it cannot hurt to make it adjustable.
When it is finished, I am curious how much influence it has.

aus230
WA, 1659 posts
1 Jun 2013 10:57PM
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Started thinking about wheels, I was going to buy some (might still) but in keeping with the purpose of this site I might have a go at making wheel's out of glass using the same method as I used on my class5 but in 15".

Picked up the timber for the plank and spring board today. The next part of the build should be fun as it all goes together.

US772
332 posts
2 Jun 2013 5:26AM
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Select to expand quote
aus230 said..

It is about the same adjustment as I have on my class5, even a couple of degrees at the bottom has a large movement forward and back at the top of the mast. It sure helps with the tuning on the five so I should imagine it will help balance the yacht.(bugged if I know,seems like a good idea)

Another question. The rear plank on the class3, any one know how thick,how wide and how much taper should I be looking for. Any help and pic's would be appreciated.


Some people aim for 1'' bend for 100lbs of weight on the dn iceboats. In the video attached that axle was a little too soft @ 2 layers of 15/16 x 8'' x 11' I ended up with 3 layers of 3/4'' @ 2 1/4'' thick x 8'' airfoil shaped. I taper a little in thickness as it goes out. About 1 1/2'' on the ends.

aus230
WA, 1659 posts
2 Jun 2013 1:43PM
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Thanks for the vidio, I can now start on the plank

Starting to look like somthing now.





Chook2
WA, 1244 posts
2 Jun 2013 3:39PM
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"FOR GOD SAKE VIC!!!!!" Even your bloody lawn mower is black.

Hey that's looking REAL sweet. Outstanding project mate.

aus230
WA, 1659 posts
2 Jun 2013 6:31PM
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Bugger the timber I got hold of is only 175mm wide, may have to get a couple more 200mm wide
Chook it has yellow wheels, should paint them black to

aus230
WA, 1659 posts
6 Jun 2013 6:30PM
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Glued the plank and springboard together today (thanks us772 made this very easy with your video) Now I can start sanding shaping and fairing every thing.

kiwi307
488 posts
8 Jun 2013 5:49PM
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wokelliott said..

Hi Vic. Looks like a standard ratchet jib sheet winch off a yacht but usually has a hole for a winch handle on top. The handle eliminates need to have pulleys to gain boom tension and only a short sheet needed. The sheet is wound around the winch drum one or two turns clockwise only. Looks like the sheet from the boom is the one thru the pulley on the right - direct 1:1 pull to the boom.

Don't know what the other rope left of the winch would be...could be a system of fine tensioning the other end of the sheet 5:1 to eliminate having to use a handle on the winch drum, that would be simple and easy to organise too. (You can then save the winch handle to threaten other sailors who get too close)

The drum has a ratchet to hold tension on the sheet and allows you to release rope quickly. They make plastic versions quite cheaply or a man of your calibre could easily make one. I have seen a home-made version where the maker used a ratchet gear sprocket from the rear wheel of a bike.

Actually I take my hat off to the builder for using the winch instead of a set of pullies and long sheet. As you tack or jybe the sheet comes in quick, final tension or trim with the handle, or preferably that other end of the rope, and no metres of rope all around your feet. Bloody good idea, why didn't I think of that??...W


Many pilots in Europe will not use a ratchet on a 3, in fact the was talk of banning them at one stage as a result of a number of nasty accidents. The snubbing winch can always be let go, whereas a lot of ratchet blocks mean you have to pull in slightly before they release.

aus230
WA, 1659 posts
8 Jun 2013 6:07PM
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thanks Kiwi,
I am going to use a snubbing winch.

Today I tapered the plank from 60mm in the center down to 36mm on the ends and rounded the edges. I am only getting 20mm deflection on the plank when I put 90kg in the center, I don't think this is enough should I taper some more or shape to a more aero foil shape until I get some movement.(it bends more when I jump on it)

US772
332 posts
9 Jun 2013 9:27AM
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I would go aero first. Then see what happens. If it's too stiff taper slightly and re aero shape.



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"Class3" started by aus230