Forums > Land Yacht Sailing Construction

UK Wooden Mini Build

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Created by Westward > 9 months ago, 31 Jul 2014
Westward
47 posts
31 Jul 2014 8:38PM
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Hi guys,

First off, what a great online resource this place is!! Its so interesting to read up on what you guys are fabricating next! I love the home build ethos, it seems the right attitude to my mind to be competing on who can do it cheapest !!

I am a Nube to the world of sand yachting; I live in a village called Westward Ho! North Devon and I predominantly spend my free time surfing. During the winter months we get allot of onshore wind that has a tendency to turn any surf to mush so I’ve been thinking for a while i should have something stashed in the garage for such days.

We have a pretty big tidal range (approx. 8-9 m depending on which chart datum you look at) and the beach is totally covered twice a day leaving lots of flat hard sand to play with. Even though I'm a Naval architect and work in shipbuilding im no metal worker so I am "trying" to build a 5.6 mini out of wood, luck and hopefully minimal duct tape.

It’s based upon some plans that I got from Stevenson Projects in the US. It’s called a Vector Landsailer. I thought working away from a proven design would give me a better chance of it being tough enough. I have made some modifications to the design;

The original has wings next to the cab for "hiking out" witch i am not going to fit.

Having looked over the mini designs on the forum the mast positions seems to be approx. 65% length between wheel centres so i have moved the mast position back from the original. The drive for this is because I'm using re-cut windsurf kit so as this is a marked departure from the original.

Anyway ill stop chittering on and put some pictures.














sn
WA, 2775 posts
31 Jul 2014 10:10PM
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Gidday Westy!

I think this will be an interesting project - and a few will be following your progress pretty closely.

I was emailing the mob that sell the Vector plans a while ago - trying to find out if these would fit into the 5.6m loop rule,

They never gave me a usable answer, so I let the project slide.

At the time I was researching alternatives to steel chassis landyachts for a local school - and the Vector might have fit the bill.

How is the steering arranged in the Vector - none of the promotional photos have a decent view.


stephen [in not so sunny western Australia]

aus230
WA, 1659 posts
31 Jul 2014 10:21PM
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Welcome to the forum,
i think the vector will be a great project, lots of different shapes to work with, Watching with interest .
Cheers
vic

Chook2
WA, 1244 posts
1 Aug 2014 12:12PM
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Welcome!!!

8-9mtr tides.

Geez we only get 800mm difference from high to low at any time of the year, on the south eastern coast of Western Australia.

I admire your wood construction. Keep the photos coming please.

Chook

Westward
47 posts
1 Aug 2014 8:55PM
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Hi Guys,

Thanks for the comments,

Stephen - I’m pretty sure that the vector as drawn would fit in the 5.6 mini rule. It is longer and narrower than the 1.3 ratio that seems to be noted on the forum. There is always scope to adjust the position that the rear axil is positioned on the tub if it is just slightly over.

Take a look at the picture below for the steering arrangement from the Vector plans. I’ve deleted the dimensional info of the scan as I’m a bit unsure of any copy right stuff but I’m sure it give the idea. A stringer either side supports the front wheel axil. In the plans the axil is pinned on the left hand side and allowed to slide forward and aft in a slot on the right. I’m sticking to this in principal however instead of using a pin I’ve got an arrangement that uses a ball joint captive between two cheek plates. I haven’t got any pictures of that yet but when I’m on to the forward stringers I'll post some.

I have read on here that hand steering is not ideal and it does seem a better arrangement to steer with your feet and work the sheet with both hands free. Unfortunately as you can see in the picture of me lying in the thing there really isn’t much room for feet steering. The lads in the office (between sniggers of "that’s never going to work") have nicknamed it the coffin.

Ill just cover the mods that Ive made to the design. not sure if they are for the good or not.

1. As i noted I’ve moved the mast step back, the original plans had it right at the fwd end of the tub. In the plans it is to be rigged using a large gaff rig made from tarpaulin. I'm going for the windsurf kit approach, we have a local sail maker in the village who I’m hoping to get to re cut a wave sail for me.

2. I'm a bit concerned about the torque loads applied to the tub by the rig so in the region where ive decided to put the mast foot I have added a ring of stiffening with lapped brackets fore and aft and doubler plates set under the deck and on to the bottom. I hope this will stiffen it up enough and prevent the thing "racking" on me.

3. for the initial test I’ve got a steel bar axil off a kite buggy for the rear axil. However the intention is to make up a wooden plank axil. I have some long strips of cider sitting in the garage so i figured ill put it to good use. As i want to be able to remove the axils (i have a small and extremely untidy garage) I’ve added in a doubler plate for bolting and a dingy style axes hatch in the aft deck.

4. I’m not going to fit the "wings" that are shown on the design. Again this is a storage thing really. I’m going to add additional half round dowel stiffening to the cockpit sides to try and compensate for their loss.

Any comments/ critique that you have would be greatly appreciated.













lachlan3556
VIC, 1066 posts
1 Aug 2014 11:25PM
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Excellent! Although that steering design looks, umm, interesting

landyacht
WA, 5921 posts
8 Aug 2014 9:27PM
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personally I dont think the steering will work properly as it will steer right, pull right , but fight you to steer left or straight
i see you are using a polyeurathane glue. I have tried it on a wooden landyacht build but found that it couldnt handle any kind of twisting load. IE it simply cracked at every join. i had to epoxy and glass over every join.
i would also suggest checking your glue for waterproof capabilities. I tried a new polyeurathane glue that was brought out by selleys. it stated that it was IDEAL for boatbuilding. I glued 3 blocks together and the next day dropped it in a bucket of wwater . the plan was to soak it overnight then smash the joints to see if it cracked through the wood or the glue joint.( it should break through the wood)
imagine my suprise 15 mins later to see 3 bits of wood floating.
in the small print on the back of the tube it said" not for below waterline use" FFS

Westward
47 posts
9 Aug 2014 9:50PM
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Hi Landyacht, Thanks for your comments. really appreciate the feedback. Its a steep old learning curve. I hadn't thought about the problem you point out with the searing. Ill have another think about how i do it.

The glue that i have been using is called Gorilla Glue. I'm building a hollow wood longboard at the moment as well and i have been using the gorilla glue for that so i just figured it would be ok on the yacht.

Your comments however have filled me with dread and a quick google on the topic shows that there are mixed reviews over this glue. It does appear to be water proof but your comment about it not being great in torsion looks to be bang on.

I have used screws on roughly 40% of the joints, mostly the ones that were to tricky to get clamps in to. I will make sure that i back all the joints up with screws first off. when you say apoxy and glass do you mean that you re glued joints that sprung with epoxy then glassed over or is it all the same stuff? I've not had any real experiance with glass apart from glassing a fin for the longboard.

Thanks again for the comments.

All the best

Bynorthsea
104 posts
10 Aug 2014 3:21AM
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I used Gorilla glue on my ply tub and it has survived a season of beach sailing / wash down after use. I have to say I think you are very brave going for a monologue as a first build, steel chassis are much easier to chop and change, searching to get the balance right, worst comes to the worst you could drop your tub into an A frame. Beach sailing can be fast and furious and I would not like to do it without footbar steering. You mentioned earlier about laminating cedar for your back axle, have considered skis, I have them on my yacht, they have taken all the hammer a very lumpy beach can give and the are excellent at absorbing gusts

Bynorthsea
104 posts
10 Aug 2014 3:24AM
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........... spell checks!!! Monocoque

Hiko
1229 posts
10 Aug 2014 4:28AM
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There seems to be a mixture of success with gorilla glue
I tried it once and decided it was both an insult to the concept of glue and gorillas yet still read of people using it
presumably with reasonable results but I won't be touching it again
Agree with the endorsement of ski axles I have been using them successfully for a few years now

aus230
WA, 1659 posts
10 Aug 2014 9:58AM
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I have used all types of glue when building my kayaks and yachts. Never had a problem with any of them, Maybe because they have all been covered with light woven glass. The resin seeps into the joints and timber when applying the covering and it ends up very strong(not a lot of extra cost in doing this and I think it is well worth the effort.

wokelliott
WA, 179 posts
10 Aug 2014 7:31PM
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Hi Westward. Love the idea and shape of the yacht in ply but after seeing only limited construction detail on the web I am concerned that the twist on the body between mast mount and rear axle will cause it to twist up and look more like a propeller. Perhaps there is a boxed section beneath from front to rear that I can't see, I regard that boxed section or a round section metal pipe from mast to axle as essential.

As an experiment.....If you use an unopened cereal packet and try to twist it, it will be surprisingly rigid and resist twisting until the cardboard collapses. If you then open the top lid it will loose all twisting strength and collapse.

Can't comment on the Gorilla Glue as I haven't used it. Cheers...Wok

landyacht
WA, 5921 posts
10 Aug 2014 8:12PM
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re the gorilla glue, i had a discussion with a NZ boatbuilder/designer about that brand. he swore by the stuff.I have not been able to get that brand in Austarlia, so perhaps I only tested a cheaper(nastier) version. I would recommend doing some tests on it before you glue the deck on. you may well find that you will need to add some small stays to control the twisting.
you look like you are fairly light and have your weight forward so as long as you dont have a HUGE sail like some of the Euro's and some well padded Aussies you may be fine

US772
332 posts
11 Aug 2014 11:45AM
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I went the wood mini route on the first go around. Mine had a bulkhead behind the front end as well as a curved section in front of the wheel to enclose it. I made a wood box that went from the top of the fuselage to the bottom with kletes to help support the mast. It was about 8'' for and aft. The boat did twist and break at the rear where the axle bolted to the bottom. To make that area stronger I fabricated some 1/8'' x 1'' aluminum strap in to an angle. More like an L shape with the short leg picking up the axle to fuselage bolt. The long leg bolted into the side of the 1/4'' fuselage with the help of some 3/4'' blocking 3x5 glued on to the side to spread the load and help the bolt head not tear through the 1/4''. I sold the boat and it's still going strong today.

www.seabreeze.com.au/forums/Land-Yacht-Sailing/Construction/Wood-Mini/

Chook2
WA, 1244 posts
11 Aug 2014 7:38PM
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The EPP Foam, radio controlled gliders we import from New Zealand, have "Gorilla glue" supplied with the kits.
It's amazing stuff that is fantastic when applied to damp surfaces. It glues really well and it expands to gap fill as well.

BUT, if the tube is left for more than a month or so unused once opened, it sets up hard.
Reacting to the moisture inside the bottle I guess.

Even in some pretty horrendous crashes the glue joints never failed on the foam or wood.

The Bumblings equivalent here "VICE" is crap!!!!
It has zero flex like Landyacht said.

Westward
47 posts
12 Aug 2014 3:04PM
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Hi Guys,

Thanks for all your comments!! This is turning out to be a bit more of an experiment than i originally thought :-)

To answer wok - there is no steel in this project so far (apart from the mast foot and axils) mostly because I have no welding kit an my garage is just one large fire hazard. You make a really good point though, if it doesn't look like its going to work (and i don't trash the tub) i can have a bash at building a LL mini.

I would be daft to ignore all the advise of the so i think that i am going to do a combination of modifications.

It definitely sounds like i am going to have to do something in way of stiffening the tub around the cockpit area as it seems a common thread in the comments that it will have problems translating the torque from the mast to the axial with out it all going horribly wrong. The vector plans show a wind shield arrangement that goes on the deck and picks up the sides of the cockpit. I was going to fit this for the "rocket ship" aesthetic but now I'm thinking it might be a key structural part of the design.

I will defiantly follow AUS 230's advise and add in some glass to the longitudinal runners and the ring frames that i have put brackets to. I think from reading through all the comments with regard to Gorilla glue it will defiantly need supporting in shear / torque.

As US772 has been though this already i will take heed of his comments and try to stiffen up the region where the axil connects to the tub. It is quite tough in there already i think as there is it is all boxed in by the seat back and the tail plate at the aft end. Ill probably add in some brackets from the doubler ply in the bottom to the sides (and use glass)

I had thought about using ski's for the rear axil and i have read some really interesting threads on here of people using them. I am trying to do this on the Cheep though and unless i see some up the tinkers yard at the dump ill stick to the ceder as its not going to be used for anything else.

Thanks again for all your comments and advise.

All the best

Westward

Chook2
WA, 1244 posts
12 Aug 2014 6:43PM
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Love it!!! Don't get discouraged. Head down bum up and get sailing.

With your timber skills I can see this is going to be an outstanding first build.

Keep us posted..................

sn
WA, 2775 posts
12 Aug 2014 7:16PM
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I have no idea how stiff - or flexible the cedar axle design will be, [having never worked with a timber rear axle set-up]

But I reckon with a set of ski's under the back it would reduce the amount of twisting stress on the coffin.

If the steering design turns out to be wanting to hang a right all the time, you could always bolt a Lefroy mini type of front axle in its place - using pushrod steering.

The blokes in the USA that made these things seemed quite happy with the results, so build to the original plans and see what happens.

Keep up the good work!


stephen

Westward
47 posts
25 Sep 2014 8:26PM
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Hi Guys,
Just thought i would post a breif update of where i am with the build. Progess has been a bit slow of late due to working away from home and children but some has been made non the less.

I found a cheep pair of skis for £10 on flebay so i am going to take the advice above and use them for the rear axil. I have stripped the bindings and measured them up to find out where to cut. Its going to be 1200 long and im going to keep them intact. Any advise on how people have cut them would be really appreciated.

I have also glassed up the runners in the structure, it hasnt come out very well in the picture but i hope it will make some difference. All aditional screwing and filling work has been done so im plowing on with the fwd runners and stering. I realised that as i have moved the mast step back I have freed up space for feet stearing. I've attached a sketch of what im thinking.

Comments as ever are highly appreciated.

All the best

Dave
















Bynorthsea
104 posts
26 Sep 2014 4:26PM
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Have a look at the ski axles and mounts in my pictures

Westward
47 posts
26 Sep 2014 8:32PM
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Hi Northsea,

Thanks for the info. Ive had a look at your pictures. great build! Ive got a couple of questions about the skis.

1. I am a bit worried about the holes for the binding acting as points of stress concentration and the skis cracking, ive seen that reported in one of the other threads. I can see in one of the shots that you have filled the binding holes in with something, what have you used? I was thinking of using eather some GRP resin or some Arildite.

2. Reading your thread my understanding is that you have clamped the skies on to the frame and bolted them at the axil. Have you also put a location bolt somewhere to stop them sliding out of the frame?

3. A silly question really but what did you use to cut the skis? I was going to go at mine with determination, hack saw and a stack of spair blades.

Thanks again

All the best

Dave

Hiko
1229 posts
27 Sep 2014 3:31AM
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Hi Dave
I have used ski axles successfully a few times now I double them up face to face and mount them with two 10mm
bolts 250mm apart on the inboard end The stub axles are bolted on with two 8mm bolts 50mm apart The stubs are welded to a small flat plate and there is a matching backing plate on the underside
The binding holes should be kept away from the stress point where the axles leave the body of the yacht and all should be good. The skis doubled up give a good amount of flex for a small mini size yacht
Skis vary a lot in how they are constructed depending on the manufacturer I use a cut off disc in an angle grinder to deal to them. Filling the binding holes would only be cosmetic I feel You could lay some glass over the hole area
which would be better but I haven't bothered and haven't had problems
Hiko

Bynorthsea
104 posts
27 Sep 2014 4:32AM
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I used epoxy resin to fill the old binding fixing holes. I have one set made from a single pair of skis they will put my yacht into mini regs and a second set, slightly longer made from two pairs. By coincidence rather than design my longer pair have a mix of one solid grip ski and the other grp and wood strip. Both pairs are used snow side to snow side and are only fixed together by the axle mount, two m8 bolts spaced as wide as poss. The inner end fits in a socket about 40mm then clamped into a U section. In the pocket I have a 10mm setscrew that just goes into a dimple in the ski, I had found that without this the skis slowly worked their way out of the pocket. I sail on a very bumpy beach and the axles have not failed. Cutting the skis has never been a problem just a good hacksaw blade, hard on the steel edges but once though ok.

Westward
47 posts
23 Dec 2014 9:49PM
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Hi Guys,

Its been a while since i posted anything about the build. ive been holding off so i had some more photos and some more bits compleated.

Progess has been a bit slow in these last few months but the rear axil is pretty much finished and im aiming to make some progress on the tub over the xmas break (inbetween dashing around the contrary to see the tribes.)

Rear axil.

I measured the skis (as in the picutre i posted last) and made cuts so the parabola of the edge was symetric. To fit in the 5.6 rule (with a bit of margin and builder tolarance) i have gone for a 1200mm wide axil.

The stub axils were inialy sized up to be made out of regular mild steel so with a 20mm dia however when my dad came to machine them up some titanium aloy was rummage up in a freinds stock pile. So the stubs are quite a way over spec.



We are pretty sure its a magnesium alloy, lots of sparks were made when machining. The axils are slotted in to some aliminium plates and the under side of the plates has been recessed to the taper of the ski to make sure everything lines up and is true. Im really pleased with the way the axil has come out.



In addition to this work on the axil i have been boxing off the tub at the aft and forward end. both are having a doubler of 12mm ply inside the line of the 3mm external ply.



Progress has also been made on the sail as well. I have been given an old but undused Hoop windsurf sail.

I took the luff offset measurments from Landyachts sail example and compaired them to the ass measured offsets of the existing sail. As the comparied %age diffrences are pretty close im not going to alter the luff. however i am getting the foot reduced from 2.1m to 1.55m to make the sail fit the yacht and have a reduced sail area. The sail maker is going to make this changes as well as flatten it off for me. He quoted me £80 for the work for peoples refrence in the UK.







I hope the infomation is of interest to people. Sorry about the spelling im knackered with out a spell checker.

All the best

Dave

Bynorthsea
104 posts
24 Dec 2014 4:34AM
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£80 seems a lot when you could do the job you self, you could buy four sails on EBay for that. I would suggest that it is much easier and better to recut the luff rather than the outer edge, in doing so you have a better chance of getting the battens at a reasonable angle. For the ones I have done the first important thing was to buy a sail that was the right shape for recutting. Then make a luff template for your mast, cut the sail and rebuild a luff tube, cutting down the original. Don't finish the bottom of the tube but put in on your mast,on the yacht, jury rig your boom, down haul on your luff tube and a main sheet. Tension the sail/mast, make sure the boom is at the right hieght and mark the base of the sail, if your lucky you can sometimes retain the outhaul.

Westward
47 posts
7 Jan 2015 9:40PM
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Thanks for your comments about the sail.

I would like to takle the sail myself but with a 9 month old my garage time isnt what it was so im happy to pay for a pro to do it.
I checked the luff against the offset info that Landyacht posted in his sail re cut description and im pretty sure it wont need alterting. They sail maker is going to sort out the batten pockets as part of the recut and fit outhaul and down haul eyes.

I did manage to get out in the garage at the weekend and have made the doubler plates that back up the holes in the tub for the skis.

All the best

Dave






Westward
47 posts
12 Jan 2015 5:46PM
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Managed to test fit the axil this weekend.

There is a center web to go inside the tub that locks it in place. Images of that to follow.






Westward
47 posts
13 Jan 2015 9:19PM
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Hi guys,

I sorted out my center web this morning, the image is of it "dry fit" to show the concept. The skis are clamped between the ali angles and some flat bar (not in the image) to prevent side slip. The axil is 90 deg to the CL of the cart when the skis are up against the aft end of the slots in the tub sides. fingures crossed this sould be enough to keep in in postion.

Luck was on my side with the positions of the binding screw holes as they are inboard of the tub side and ski pivot point, hopefuly reducing the risk of cracking.

All the best

Dave



US772
332 posts
14 Jan 2015 12:14AM
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my first mini was wood like yours. I found it too weak where the axle and fuselage connected. It tore the 1/4'' plywood off the stringer in the outside corner due to torsional pressure from the mast. I fixed it by reinforcing it with 3/4'' plywood extending up from the bottom corner of the sides of the fuselage about 6 '' high x 4'' wide. Then I attached a steel l strap from the axle to fuselage attachment bolt to the 3/4'' blocking with bolts in an L shaped fashion.If you wish you could achieve the same by adding blocking around where the ski exits the fuselage sides and between the ski and bottom skin. Move the aluminum angles out ward to the inside side of the fuselage sides and bolt to the sides of the fuselage and bolt through angle, ski, blocking, and bottom of fuselage. If your rig has shrouds disregard.

Bynorthsea
104 posts
14 Jan 2015 4:32AM
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I agree with US722 you need to mount your ski axles in some sort of cross beam, clamping into a steel channel that in turn is fixed to your tub is the simplistic, have a look my photos. The only mods I have had to make is to add a locating crew at the inner end as they tended to work their way out over a sailing session.



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"UK Wooden Mini Build" started by Westward