Hi to all, been reading this forum for around a week and have convinced myself that i need a LLM in the garage, the construction of the chassis seems pretty straightforward and i will follow the plans (almost to the letter)for ease of build, have my welding gear and have built stitch and glue power boats before.
The one thing i am not to hot on is the sail/mast, i have managed to pick up a alloy laser mast and a windsurfing sail from the tip, could i use this? i know that the sail will need the pocket recutting for a straight mast, time is on my side but alas a budget is not!!
Thanks in advance Phil
Welcome Phil,
This is probably NOT the answer you want but here goes... If the laser mast is in good condition and the top section is straight, sell it on eBay, they are rare as...
With the money get a good set of wheels and then talk to the local sailboard guys to see if they have an old fibre glass or carbon fibre mast for the LLMini.
Thanks for your quick response, Alas the mast is broke on the bottom, but looking at the plans/pictures if i extend the mast support it will be long enough, not sure( uneducated!!)if the flex on fibreglass mast is needed/ designed to work with the windsurfer sail
Your probably better off trying to find a fiber glass or carbon fibre mast as the flex makes the yacht a bit easier to sail and takes the pressure off the mast step.
Extending the mast step and a stiffer mast may cause problems.
Hi Phil,
The Ol' Gizmo is talking sense with the Mast.
I have recently built myself a couple of Land Yachts, a Pacific Magic and a LLF Mini.
Both use Carbon Fiber Masts which I got by putting out the call in the Windsurfing Fraternity. Also keep a close eye on eBay. The following is what I imagine and no doubt if I am wrong I will be corrected.
There is a horrendous amount of pressure comes against the Mast Step Base, so it does need to be every bit as strong as Paul's Plans suggest. I should note that though they are flexible, the Aluminum Masts are a bit stiffer than Carbon Fiber.
From the above info I would dare to say that the CF Masts tend to absorb a lot of Gust Power and then release it at a slower pace. I found that with the Mini it takes less effort to get an up wind wheel off the ground, therefore a stiffer mast will put you on your side more easily. With the Pac' Mag' I found, Yesterday, Wind was about a 5 - 6 on the Beaufort Scale. That the wind in surges would kick the yacht in the Butt and accelerate very quickly and now and then Lift the upwind wheel off. Again the CF Mast absorbed the Gust Shock and gave good warning as to the next action (Wheel Lift). If you look around whilst building and plan for a CF Mast you can always use Ali' or other. In the learning to sail these things one needs a brief space to think of your next move where as, as you gain experience and confidence you tend to learn to react before thinking a bit like driving. When some Schmuck pulls out in front of you or enters a Round- about right in front of you everything happens in Automatic then you have time to Crap in your Pants 
. I nearly did yesterday. I let the sail out wanting to slow down and the Bloody thing Took Off, luckily I had enough room to pull in a wide turn and get the wind out of the sail. I don't know what speed Occum's Razor got to but it Damned Well looked fast and would have removed a goodly patch of Bark had I come adrift
Above all else in new build (For a Newby) Listen to Paul and Cisco these jokers have been at this game for years.
Ron
Pretty much talked myself out of using the alloy mast ( may come in handy for additional parts/materials later) spent this morning reading as much as i can and now makes sense using fibreglass (kinda like a shock absorber) Thanks for the sound advice all, will starting the build at the weekend,best check that mig gas first!!!!
Phil,
On CF Masts and I would imagine for Glass ones;
You will no doubt have to shorten it to suit your LY and Sail which is OK if you are lucky enough to get a complete one. Use you Common Sense here. Do not be afraid to buy broken Masts, specially the Lower section. Just as long as the sections can be fitted together with plenty of overlap. The Mast I am using on Schrodinger's Cat is made up from a few pieces of broken mast, luckily I managed to get 3 or 4 complete top sections and a bunch of broken Bases
. I built up a base to suit the Cat (Be very careful when handling this stuff as the Splinters can be very nasty)
If required a longer piece can be slipped inside the mast base to stiffen/reinforce it. This depends Largely on the type/size of the LY you are going to build. I was lucky enough to Buy a near new Mast (Undamaged/Spare) and enough to make 2 others plus 2 Axle sets and some Left overs for $400. I would also suggest that you Sleeve the section that is inside the Mast step. I add a note here, I seem to think there is some rule or other if you are going to compete about CF and or Glass so check this out as well. Me I'm in this sport for the fun of it and not competition.
I do not know if there is anybody out there that Has used/Is using Carbon Fiber If so I would like them to get involved as my experience is fairly narrow and I tend to prefer Over Engineering in places of extreme Stress of which Both Mast Step and Mast Base are under.
It should be understood that Speed CF Masts are under extreme Compression stress, due to the method used to tension the sail. However the Mast is Pivoted at the base and only the Sailors weight counters the wind to keep it upright. Hence it is my strong belief that an inner sleeve of at least 750mm long should be run up inside the Mast base as well as the shorter outer Mast Step Sleeve these sleeves also protect the Mast against CRUSH Pressure. It is always best , in these cases, to err on the generous side than be a little mean and lose a valuable commodity and your precious labor. Think the whole thing through before going ahead with the build.
Do not be afraid to contact me if you need a little help Hopefully there is someone out there that is using CF as well to help you.
Ron
PS, Where sleeveing is concerned I have used sections of CF Mast Split and forced down over the Base, once again Cutting CF is a dangerous process, in that you do not want to breath the DUST!
use a good mask all cuts should be sanded lightly to remove splinters and possibly sealed with an Epoxy Resin to prevent more splinters. The dust can also make you Itch so a paper overall is an idea.
Laser mast will be fine
Ommmmmmmmmmmmmmmmmmm.
was that post technical enough for you all
Paul, Is you having a shot at me?????
After All, I did request some back up or further input to my findings in the mater Either to Concur or repudiate!![}:)]
Ron
I sectioned a windsurfer mast that has heavy wall kevlar and sacrificed another lighter wall mast for the joiner inserts.
I doubled up by using cuts along the sacrificial mast and sanding them for precise fit and epoxy glueing them into the mast lower and mid sections.
The plug inserts are 500 mm long and are positioned midway at the join of the sections.
All being of equal taper it was just a matter of sanding material until the desired result is achieved.
The white mast is actually a fibre glass radio ariel mast, some of which was used as well, particularly for the top section extension with which I backed up the epoxy glue with 4 self tapping stainless screws due to it carrying the load of the downhaul.
The base section of the three piece mast has one of the alloy tubes in the pic inserted, spaced with pvc split pipe between the mast and the tube to eliminate slop and a hardwood plug 100 mm long in the bottom.
The alloy tube is secured in the base section of the mast with epoxy glue but more importantly by the s/s self tapping screws that also secure the split pvc pipe cushioning the mast base section against the top of the mast step.
In the following pic you will see a white mark on the back of the mast which denotes the top of the alloy reinforcing tube. You will also notice that the mark is just below the gooseneck which is only static "hauled down".
Believe me, this is an excellent "flexy" mast because I made sure it would be. But it is still a "flexy" mast and therefore a bit tame for an LLF Mini.
My first sail in an LLF Mini was with my chassis and seat with a sail made from fertiliser bags and a "stiffy" alloy mast both made by Paul Day.
It was WILD.
I steered using the slight slop in the steering head. Anything more was "can out material". Paul has admitted that he could not catch me with my blokart with which he won the first prize trophy in his weight division a couple of years ago at the blokart nationals at Yeppoon.
Paul gave me the sail, sold me "Nappy Rush" but took the mast home because he reckoned it was worth $300.
I have asked for the specs for that mast a couple of times but so far they have not been forthcoming.
Here are the specs for an alloy mast that do not appear to have the Paul Day trade mark on them.
Cisco,
This thread may sound a little defensive of my build, however if I have made any mistakes I am willing to discuss them and further my education and who knows an inexperienced and fresh view may add to the knowledge base for others to gain insight.
A lot of the Mast Base construction will depend on the type of mast Step being used on the Chassis i.e. If one constructs a Simple tube fixed Mast Step and is using CF then I am unsure what Reinforcing I would use. I may be being over cautious but I do feel there is a hell of a lot of stress at the MS outlet where the Mast Leaves the step even with Flaring. As Pic shows
I chose to design the Step after this fashion for several reasons.
I felt the the added flex in the Step itself would allow for Stress relief on the CF (Carbon Fiber)
I could construct a support device at the top to spread the pressure load out.
Looking at the structure of the CF Masts I have, I thought that they looked as if they could collapse/crush fairly easily thus I decided to make them beefier at the base up to 750mm I also added a small (75mm and 300mm) section on the outside of the mast at bottom and at the Mast Support (Noticeable in the Pic) . This gives the Mast added reinforcing at points of most stress as well as allowing more movement in the Mast Step itself. Being as these are my first builds I have not had a great deal of experience so I have had to work with My form of logic and common sense. I would have to have someone like yourself or Paul test the both machines to give a more accurate opinion but I have found that with my 100kgs I do get plenty of warning from wind gust shock to counter it by weight shift and Sheet slackening This method has given me cause to doubt my technique as I performed the Counter Measures only to have the Razor accelerate heavily and have my Sphincter begin chewing at the Seat for extra Grip.
Ron
The Pilot in this pic is an inexperienced woman of 52 Kg and the Razor was on-the-move.
If you really want to go technical when it comes to windsurfer masts, then spending half an hour at this place will blow your mind:
www.peterman.dk/start-windsurfing-samlet-gb-dk01.htm
I find the mast test results (with bend curve) especially useful when comparing different brands / models of mast.
. it has 500mm of Douglas fir up the bottom,silasticed in , thats all. we avoid screws.
OK! Guys,
I think Paul may well be somewhat in accord with my thinking.
Cisco I felt that one could afford to lose some flex out of the Base as suggested by Paul and the Use of Douglass Fur and the insertion of 10%CF into Glass. He has in effect done the same as I have, stiffening and reinforcing the Mast Base against Crushing and Tension Fracture. Without Taking Flex from the upper section.
I have no doubt that what is said on that Web Page is correct for Windsurfing BUT! We are using FG and CF Masts designed for Windsurfing they are attached at the Base by a Flexible "Mast Step" (For want of a correct term) bringing the Stresses via the Boom to bear at a higher point. Being as the counter weight is a Human Body subject to absorbing the shock or being thrown from the Board. Where as the LY has the Mast Step firmly fixed to a Chassis at the Base of the Mast Giving a Totally different Set of Stresses and Dynamic to the way the Mast is used. Therefore one has to take these stresses and dynamic into account. I believe I have proven this to be the case in a way as I managed to, through my own fault, break a mast Base. In the Case of of Both LY and WS's think of the Mast as being somewhat of a Bow (Probably the Japanese style) On a Windsurfer The Bow is Drawn at the Boom position whereas with the Land Yacht we are trying to use the Bow by holding it at the bottom of the Limb and Drawing it, at varying degrees, throughout it's length. Result Bust it off where it is being held Rigid (As I did). I am using 100% CF Masts which are around 3mm wall thickness and I think I am right in my thoughts for these mast types.
If I am wrong I will admit to it BUT "By all I hold sacred" you are in for a Fight to get me to admit I am wrong[}:)][}:)]
-------- For I am Seldom Right but NEVER Wrong
Ron
PS it also should be noted that WS Masts are under one Hell or a Lot more compression than we put them under in our application. 3 to 1 Pulley Block tension and also Cranked down with a 150 - 200mm long Crank Handle attached into the Mast Base. Think what a fit young Wind Sailor could pull against the Mast and sail with this sort of Leverage. I shudder to think. AND Yes they do Blow Masts regularly. Talk to David Morehead, whom I bought my Masts from..
OK! Now here is a definite problem All things of major Importance such as Masts, Chassis Plans FISLY Requirements etc really should be put into Labeled Folders and Locked in order to the head of the Land Yacht Page. Yarns of escapades -----Well they are just that and a great read but should be allowed to fall by the wayside over time as interest is lost in them. For instance Masts Plans of varying Mast style and their properties should be stacked in the one folder and as Paul has noted; WHY Aluminum Masts are desirable, competition rules etc. Another instance could be in using a CF Mast which end should I cut off to match my sail????? I didn't know so I took it off at the base which through a streak of luck I think was correct in this case, however had I needed a stiffer Mast for my rig it would have been the wrong thing
Hmmm
One could use a Hickory Sapling as a mast but why we shouldn't.
I think such things would save valuable info from being lost or searching the entire site for the required info.
Just a thought under my particular logic
Ron
Ok! Cisco, but remember I did say my form of logic (Ordered Chaos). Now we just couldn't deprive poor ol' Gizmo---------Could We. I should warn you however-----------Ah11 Given people like Moi, we may well need a server all to ourselves. I do enjoy a good discussion to keep my Blood Flowing and a close call or 3 to keep my heart pumping and at the moment I really do "Feel the need for Speed" and the Smell of Burning Rubber.
Hmm! Cisco was a Spanish Mexican Spanish are devout Catholics
I am irreligious and got no couth so I cannot be a Pilgrim[}:)][}:)]
Ron
Yeah. I'll go with "Ordered Chaos". When all is chaos I'll give the orders!!
My alter ego is Cap'n Sandbank. Bank not Bar.
Cisco was the "Robbing Hood" of the ol' west. Zorro on the other hand was a "Gay Blade".
Here is a pic of "Cisco".
the other reson we avoid lots of sticky.s is that newbies and Experts start to waffle and deviate, and of course they could become wrong.
Ps cisco,I made it less stiff
On the mast side of things...how much compression IS there actually do you think? Has anyone thought/able to actually measure it? Not entirely sure how one would but it might be easy(?) enough with a set of bathroom scales. Then we could all get some sleep.
Me too, as I am wondering why the LLM main tube is built so 'strong'. Yes, it doesn't fail but is it overkill? Not sure but years of sailing suggests it works well enough.
My background is in 0.9mm WT chromolly steel round tube and I know it can handle loads over 200 Kg in a 45mm section. Proven it in other applications. Some triangulation underneath the tube would do wonders too.
Then the all up weight could come down a bit.
Just my two cents.
A wire stayed rig has massive loads when fully sheeted. that picture of pigs might fly is a stayed rig , the rear axles flex by 4" each side and the front beam(55mmODx2mm carbon steel ) flexes by over 2". Thats what makes a stayed rig work. if the chassis on a stayed rig is really stiff, it will probably be a dog
, Maybe kiwi 307could comment on that opinion, as he has more experience in these things.
on a LLM there is more torsion rather than just down force, but again to stiff or too braced and the yacht will stop performing.
If you build it all in really thin wall , skinny tubes , then add lots of braces you end up where you started. the main spine in 60x2mm wall is not that heavy, you could go lighter in front of the mast. My Y frame minis are only 30x30 2mm wallin front of the mast , as the area under torsion is that bit between mast and rear axles
.
