And here's my $31 trademe sail.Now there's a sense of the home straight in this project.I need to reshape the foot of the sail
The next job is to make a seat.My 90 kgs bent the ply to a worrying extent so my design will spread the load of my bod over the length of the seat.
A question: I see that the Skimini sail is attached at either end of the foot.Is there any reason why the boom wasn't fit in a sleeve? It seems to me that this would spread the load or has this something to do with the shape of the sail under tension.
Most land yachts are loose footed on the sail like that
I guess the simple answer is that a sleeved sail is not necessary and it is easier to adjust the sail shape if the sail is loose footed
Our first LLM's were sleeved and that was ok as they were rear sheeted but the next version sail was centre sheeted giving more control of the sail(we could slightly over centre the sail by pushing the rear of the sail/boom) and with the pulleys out of the way it was easier to add adjustable outhaul.
Select to expand quotetryhard said..
The next job is to make a seat.My 90 kgs bent the ply to a worrying extent so my design will spread the load of my bod over the length of the seat.
A couple of stringers glued on the topside edges should stiffen it do you think?
Something solid for the seatback to attach to as well
Try hard
On looking at Clems Skimini design there is no weight on the plywood The seat is mounted to the chassis
All your weight is on that 
As I indicated in an earlier post, I intend recycling the windsurfer boom.My plan is to fix the 2 arms of the boom along either side of the seat ( which by the way is designed for a skinny molinky - it is a bit of a tight fit for me but not overly so.When I got married I was Clem's present weight but someone keeps putting things in my food).I am now experimenting with the material to make the nappy seat out of.I tried plastic bags knotted together to make a temporary "sling" and this allowed me to lid down almost flat which I gather is the preferred driving posture.
Another question: should I have a metal plate under the ply where the main sheet saddle is fixed? All the pictures of 3 or 4 blocks to manage the main sheet suggests some very significant forces (upward) will be at work
I have a windsurfer boom holding a nappy seat on one of my minis It has proved to be strong
I have a webbing strap on another mini that goes through a hole in the ply and around the chassis spine for the main sheet block attachment
Just a piece of webbing with an eye in each end You could use a rope lashing also Just as strong
Laying flat is more streamlined for the speed demons Sitting up a bit is better for tooling around and for visibility
Yes there is quite a bit of load on the main sheet especially with centre sheeting You are bending the mast back to flatten the sail with it
Thanks Hiko.Here's a pic of my current experiment. My welder/engineer mate thinks I need a bit across the back between the 2 arms to prevent the arms from pulling inward when I lie on it. I've been a bit jittery about this idea because of the extra risk of injury in a prang.
Lots of unknowns there like how many sheaves you are going to use How high do you like your boom etc etc
Everyone has their preferences When you rig your yacht you will have a better idea maybe use some cheap stuff
initially Generally you dont need your boom to swing out more than 45 degrees I dont anyway
Hiko is correct, the rear end of the plywood deck does not take any weight. It is there to protect your rear end from getting harpooned by debris you may sail over.
I still think you may have to move the foot peddle support post and seat forward so the steering T bar can overhang the front plywood skirt a bit more. It looks like your feet will hit the front skirt of the seat when at full lock. Your heals need to be resting on the plywood deck when operating the steering peddle.
Otherwise excellent job so far.
I wonder if I have hit a major problem.My engineer mate has constructed the steering rod set up but used universal joints instead of the plastic joint which Clem used.the problem is the alarming slop over which the front wheel does even at rest.I hope the photos show the extent of the problem.I can see that keeping the unit going in a straight line would be a major mission.Am IO missing something here?
Now the seating issue.These pics were taken with me sitting with my bum just aft of the V section welded to the spine.As can be seen, my feet stick way forward of the plywood skirt.I thought I followed the scale of the sketch fairly closely in terms of what went where.I am 6 feet tall.
I just measured the distance between the front of the skirt and the mast step is 300mm
Here's another shot of my build so learned advisors can point me to where I need to change things
It looks to me as though you are sitting too far forward your butt needs to be just in front of the rear wheels
you only want a few kgs on the front wheel with you aboard The mast and sail will add a few kgs more
put some kitchen or bathroom scales under the front wheel and tell us what you get
If your feet after doing that are still way forward then your pedals will have to be moved forward along
with your plywood bits You can see why someone said don't worry about the sandblasting and painting
just yet! 
Fun hobby this
If I sit back so my bum is just in front of the wheels,I'm sitting on the bum protector which is not designed for sitting on.So do I need to shift the whole ply assembly forward ?
Like has been said, check the weight on your front wheel first and work from there
I have a friend who can't sail my class5 yacht As soon as he gets in it the front wheel points to the sky
He is one of those long legged high centre of gravity types Maybe you are the same
You have to get the weight balance right Forget about the plywood bum protector for now we have confirmation
from the designer that you don't sit on that
Do those angle irons that you have clamped on there extend back to in line with the rear wheels?
Put a plank or something across those for now and find out where your butt needs to be
Remember you will be leaning back at 45degrees or so
Position it so you have 3or4 kg on the front wheel with you aboard
That is where your seat will be and design something around that
If the pedals and plywood don't suit then they will have to be altered ,this yacht is for you
I hope you are enjoying this build as much as I am!
Rightio chaps.I think I start to get the picture.This land yachting business is a dark art to be sure.Will the weight distribution solution take care of the steering issue I foresee?My engineer mate says the front wheel will overpower my pedals rather than the other way around.
Using the bathroom scales the weight of the front end with the mast (sail absent but I estimate .5 kg max) is about 10 kg.With me sitting on it the
weight is about 14 kg.With me leaning back to simulate the nappy chair the weight dropped back to about 11 kg.How do I get rid of all that weight if the front end weight is supposed to be 3-4 kgs?
Somewhere way back in this thread I think I remember the geometry of the steering was discussed
If you take an imaginary line and project it down to the ground it should land directly under the centre of the wheel axle
If this is so then all should be good. You have a well proven steering layout known as layover steering in common use on landyachts
The linkage however I am not familiar with , someone else may want to comment on that ?
You get rid of that weight on the front by moving your bod back If you finish up with somewhere under 10
ready to sail you should be good IMO As you say it is a dark art You won't have to move back much
You are starting to look about right in the picture 
Do you mean an imaginary line from the steering head? Might too much weight on the front wheel have something to do with the problem?
Yes these are tricky little beasts. Don't panic, we will sort this out for you. First of all you need to estimate the total weight of you and your yacht fully rigged. If you are 90kg I estimate the yacht will be about 30kg, so lets say we have a total weight if 120kg. I would recommend you aim for having 10 to 15% of that at the front wheel when you are seated in the yacht, i.e 12 to 18kg.
Take the plywood seat off for now as it weighs next to nothing. Plug the mast in. Get a plank of wood (150 x 25)1.5m long and place it across the skis so it is touching the front edge of the rear tires and sit on the plank. This will tell you where the steering peddle needs to be. I like to sail with knees raised slightly. I find it a more natural sitting position. Get something to rest your heels on at the same height as the plywood deck would be at. I notice you have holes drilled in that horizontal tube welded to the back of the mast post. Use those to position the foot peddle where you find it comfortable. That may be all you need to support the foot peddle. Could just cut off the vertical one so you can slide the seat further forward.
When you make the sling seat have a look at some of those low fold up beach chairs for ideas.
So is my butt's position relative the rear wheels not critical? That being so can I keep moving backwards until the front wheel is more manageable?
