My existing ex windsurfer mast is alloy 430 cm long. I want to use bigger sails on lighter wind days so I expect that the luff on the bigger sails will be longer than my mast.This directs me to ask whether windsurfer mast extensions (which I gather are used to deploy different sized sails) could be used in my mini.Not having seen a mast extension in the flesh,I don't know how they work.Can anyone assist?

Hi,

For starters, a bit of background. I've been wanting to build a landyacht since i first went for a ride in a two seater when i was a kid. Upon finding this forum and a bit of a rummage around my shed I realised i have most of what I need. So it has begun!

I am an Industrial designer by trade, so i have a habbit of trying to "improve" everything. However in this instance i am trying to stick to the LLF design as much as possible for the first build based on that i have not really got a clue about the deisgn intricies of a land yacht! However that being said, due to the availibility of material at hand, and an almost non existant budget there has been some...... comprimises. As a result I need a bit of help digging my way out!

As far as materials, I have an old sail board rig. Not sure of the sail area, (guessing about 5mt). A fiberglass mast about 4400 long. (Beagle shown for scale.)




Instead of the 60mm x 2mm tube I have some 43mm x 3mm seamless tube, (quite a bit actually). I cut a piece of this to length at first and performed a "load test", (i put one end on a brick and jumped on the middle!) seems OK. Also the 35 x 2 SHS is 40 x 3mm SHS. So i have but welded them together. I realise this will likely need bracing and i expect there is quite a bit of torsion at this joint.





Now the bits i'm worried about

1. I have used the same tube as the mast mount. With a bit of heatshrink, the mast will slide over this point quite nicely. Has anyone tries this with any success?




2. With the mast mount positioned as per landyacht's details, it looks to be a too far back. I assume the center of pressure should be just forward of the rear axle's. As well as the boom being too long, it doesn't look right.




3. Can anyone please advise what size wheels should be used. I am intending to run this thing mainly on the beach. It seems that fallshaw poly wheels are the go, but are there any alternatives that work, (Given I am on a budget, as with most people.)


This is where i am up to for the moment. I have an almost full photo log of the process so far if it is of any use to anyone. Just let me know and i can post the build details.


Thanks in advance!