Mast Extended.......
Bits
perfect fit
450mm
600mm
Couple of 1" ployappropriate risers and a coupling and presto. I already had the longer of the two, (600mm) but it wasn't quite long enough and needed something to sto it sliding into the mast. So a quick trip to the big green shed and $7.20 later and i have a 600mm extension and a 400mm extension.
I thought that extending the tip rather than the base was the go as there would be far less load on the tip.
Just one windsurf boom sacrificed so far The other one I want to straighten to make a landyacht boom
It was a strange build this one I made it up in parts and wasnt that confident
it was going to be a success
Assembling it all was a pleasant surprise
I have to back off now and get a lot of other stuff done
Certainly ingenious,
Hiko how does it go from a comfort perspective? It looks like the tube might be sitting across your shoulder blades.
Yes that was just one of a raft of things I wasnt confident about
In the end I just went ahead and built all the bits thinking this will work or not
When I finally got to assembly it went together in minutes and I and a few others find it very comfortable The frame is rigid and it folds up well
The basic geometry is still LLF mini so it should sail well too
Weekend after next it should get a tryout
I suspect that the spine tube will end up trying to alter the size of your backside. can I suggest taking a small sheet of ply with you to slide under the canvas if it happens.
tightening the canvas up to avoid the tube results in a trampoline effect , where you seem to be thrown from the yacht everytime your dump the sheetrope.
experiment done in August on the green arrow[}:)]
this was I had to add
Just a thought on the basic Mini design, Has anyone tried using 30mm square in place of the 35mm square on the spine. Then a piece of 25mm could be welded into the 30mm axle and slid inside the 30mm on the spine.
The advantage is you would only require 2 sizes of SHS rather than 3. I'm just not sure the 25mm would be strong enough. Thoughts?
I presume your talking about using the 25mm as a rear axle? too light.
30 is the lightest we have got away with if I was building another Y frame mini I would go up a size and use some 40mm OD in the frame and 35 for the axles.
I would technically call that a weak point try it it but I reckon it would bend.
the problem we have with this steel is that it can bend with a sudden shock load, to combat that you go up in size , rather than wall thickness, to keep the weight down. the reason we settled on the 35/30 combination is that our official test pilot TP1 caved in the door of a camry, with side bars, without damaging his axle
The 30/35 mm telescoping combination works even if you go down to 1.6 mm wall thickness.
Putting a 25 mm piece in as a joiner between two 30 mm pieces under a lateral load
is setting up for a catastrophic failure which will probably happen further from home than you really feel like walking.
I been scouring the forum looking for the thread with discussion about replacement tyres and tubes. It had the supplier contact, and I thought about $10 a set if you have an ABN. Can anyone help?
Yet another question!
What is the easiest way to modify the angle of a set of bicycle forks for the nosewheel? I've noticed several yachts in the register have used these.
I was considering placing a series of drop saw cuts and rewelding as per the "rear axle assembly" piece in the LLM plans. But i'm not sure this will be strong enough. It looks as though most of the applications of these forks are cut at the top and rotated. However they are not truely round at this point.
Any help!
Thanks
I think "iand" would be the expert on that one. He has done a few bike forks and they look really neat.
OK just to paint a more complete picture;
Firstly i abandoned the internal mast step idea. Things are done the way they are for a reason i spose!
Down side is now with all that rework the spine is bent, It has decreased the angle of the layover steering. I'll wait until it's fully rigged before i worry about that though.
Bike forks were bent by doing this,
Then lots of welding, gringing, welding....well you get the idea!
Then i made some axles.
I did this,
then this
which resulted in this
some of this
then a bit more
and, Ta-Da
Built a seat, Boys at work think it looks a bit funny for a coffin! I not sure this first build will get that fast, (i hope)
Bit of recycled ply packing 7mm ply, and some glass.
She's a bit rough, but it should do the job for the moment.
and now we have this.
still bogging sanding and painting to do. once i sort out the back wheels, and the rigging i think i'm away!
I have two things that are of concern in the back of my mind. I've followed the design as close as i could for this first build, my only real deviation is the 45x3 tube for the spine, and the bicycle nosewheel.
Also I have not had the thing complete yet so this may be premature but;
1. I'm not convinced the rear sheeting support is long enough. I reackon my head will sit right on the rigging point, (and i'm only 5'6")
2. Also the nosewheel has a tendancy to want to lay over at rest, is this normal, or have i stuffed the steering angle? Granted however i have not hat this thing with rear wheels on, also the spine is bent from the excess heat from welding, removing, re-welding the mast step.
Or am I being a bit of a princess and should have a cup of concrete and harden up!
grlynch,
I like what you are doing in your build. Great stuff. I would if I were you have a quick word with Paul about your Forks System. it would seem that the tube inside the Steering neck can bend fairly easily. under the stresses of Shock from hitting a pothole or rocks. With my builds I too Pauls word for it and reinforced the Forks Steering Tube with a solid piece of Rod. Just a thought for you to take into account.
Ron
OK another question, (i know, I know, Just sail the bloody thing!)
I've got the oportunity to make my own sheaves. Here's a prototype;
Sheave is black acetal, cheeks are 1.6mm 316 stainless, Axle and top spacer are stainless tube 1/4", "d" shackle is off the shelf.
The question is can i get away with a 25mm diameter sheave for a 10mm rope? It's just that i've noticed for most commercial blocks, the sheaves are much larger.
Grlynch, the larger the diameter, the easier it is to use, especially on the pulley closest to your hand. That said, the shorter the sheaves the closer that they can be pulled together therefore the lower the boom will go before the sheaves touch.
OK starting to look like something. Got a little creative with the paint job, seemed to be easier than actually bogging and sanding properly!
Needs a name though!
Yes i know the wheels are crap, but i've got em!. Actually i machined some bushes and fitted some 6204 bearings, seem to run pretty true, but we'll know more once i get some tires on........and the steering sorted out...........and the rigging..........man these things go on forever
I think the way you have modified the BMX bike front end to fit the land yacht is just spot on.
It eliminates such a hell of a lot of fabrication. Top marks.
Grynch,
I did the same with the Front end of the Cat. Did you reinforce the Inner Steering Tube? Paul did mention in one of his Posts that he felt that it wasn't strong enough and tended to bend under excessive load i.e Bouncing through gutters etc.
I used a solid rod but to be tapered a bit to slip right through to the base of the tube so that it can be welded in place. A heavy walled steam pipe would do the trick also. anyway keep us posted in that area.
Ta
Ron