The whole point of building your own land yacht Gizmo is to do it on the cheap by using what is readily on hand. It's a fantastic project recycling what's easily available or can be altered to suit. I'm certain you would agree with me there.

The little machines that "prairiepilot" has built are absolute corkers. It's fantastic to see the designs and how much fun he has had constructing them. I love the improvisation and photos of his process. A TOP effort.

Gismo, I really respect your input to the forum and love your engineering background to solving problems, but at the end of the day we are not talking "old fashioned" land yacht or water yacht sails here, they are so old school. Granted these traditionally designed sails work fantastically well, are required for landyacht racing, but unfortunately also cost a fortune when building a starter fun yacht.

I thought we covered uncut windsurfing rigs a while back quite well, but you refuse to take on board the windsurfer sail design trends.
I'm the first to admit, I too was struggling to understand how it was possible, but I'm a very curious and determined bugger when I put my mind to it and not too proud to take on and try others ideas. I have persevered and reaped the rewards of these $30 setups.
So rather than ridiculing us from an "engineering view point" for having a go. How bout you start to do a little research about them before making your flippant remarks about something you don't understand and have never been exposed to.

We are just using windsurfing rigs that are cheap, very readily available and go like hell when rigged correctly. The fact that they don't need out haul is neither here or there, it's a cheap form of propulsion and just works perfectly.

I would really love for you to have a go in my yacht and you could see first hand the potential of being able to set a rig using only downhaul for the different wind conditions or direction of travel.

I'm only a common farmer (and a burnt out one at that) but the bottom line is it all comes back to a sail that is designed to match the mast and it's dynamic changes.

Gizmo said..
^^^^ "A MODERN windsurfer sail and mast does NOT need outhaul to shape/set the sail."
?????? Really. I would love to see some proof of that.

I rest my case!!!

Forgot to mention this; I've read on here the most of your sails rotate around the mast but with my moving the sail back and forth the mast rotates with the sail. Maybe the results are different with pressure of the wind? Maybe because the mast is flexed so much the sail can't rotate around the mast? Does it even matter?

use original boom to start with then change if you need to

don't contribute much to forums,but with regards to outhaul on windsurfer rigs here's my contribution. firstly been a windsurfer for 40odd years (also have blokart which I use in the winter),and until recently was an RYA windsurfing instructor, Sails back in the mid seventies required lots of outhaul. But modern rigs require lots of downhaul and little outhaul but it depends on which type of sail,for freeride the downhaul is set depending on the wind strength more for high wind less for lighter... Its basically used to the set draught of the sail,the outhaul is simply pinched up to hold the sail to the boom end. BUT with racing sails most dedicated sailor set the downhaul then rig the end of the boom with a system of ropes and pullys, most racing booms have a small pulley system built into the end of the boom to facilitate this ,the idea being that after setting the downhaul, the adjustable outhaul gives the sailor the ability to alter the sail on the fly. IE more outhaul flattens the draught,and the sail performs better upwind,once round the upwind mark,loosen off the outhaul to give more power on a beam or offwind reach. Even freeride sail become unmanageable,if the outhaul slips when out sailing,so yes they don't need high outhaul but it does add to control.The standard practice being to downhaul to sail to suit the wind then,assuming non racing,outhaul and test the sail by pushing it in the centre so that the sail just fails to touch the side arms of the boom. However I don't think its particularly relevant to land yachts,because I have rigged the blokart so I can use my numerous windsurf rigs with a standard windsurf boom(4m to 9 m ) and don't seem to notice a great deal of difference from standard blowkart sails. Just my humble input.