masts

-->This
http://cgi.ebay.com.au/HOBIE-CAT-MAST-OR-IDEAL-FLAG-POLE_W0QQitemZ260272920257QQihZ016QQcategoryZ102812QQssPageNameZWDVWQQrdZ1QQcmdZViewItem <-- might be of interest!

EDIT: oops that was a bit cryptic, click on "This" in that sentence. I wonder what temper it is?? Might be good for axles etc as well.

Yep interesting!!!! ive got a piece of the stuff on the side of the shed about 6m+ long with a very slight bend in it and filled with foam.
The alloy is 6106 T6 (I believe) no good for class 5 as it has an aerofoil shape and the other problem it has a sail track which is classed as an open section in the class 5 rules. But would make a good but slightly bent flag pole!

Or something like this !!!

on the subject of masts, i was in parramount browns today and was supprised at the price of ally tubing,3.2x50mm $20ish,40mm $17ish.i thought maybee 1 50 cut in half as the base with the 40 sleeved in as the tip[a suitable bush would have to be made to take up the slack between the two] would they be any good do you think for a windsurf sail.$54= 2 cheap masts

Needs to be T6 , NOT T5 The 3.2 would make good cl 5 axles ,in reality too stiff for a good mini axle. Weve used 40x3T6 for cl 5 axles but they all failed. Ifyou get a sudden knock like dropping off 2 wheels hard the tube bends and doesnt recover. It might be Ok for mini tho , it would flex nicely over a short length. . I assume price was per metre. not a bad price . same as 25 years ago

that goldspar list was intresting.
the good one in that was the Finn and OK dinghy masts 64x4.5mm wall both unstayed yachts. all the rest were probably too thin walled to use unstayed or on thier own

Lachlan had asked about the mast on L,P and I. . heres the specs.
lower section 2200m x58 x2 cold drawn steel NQ core tube.
middle section 2200x50x2 cold drawn steel BQ core tube. 200mm overlap
top section 1800x44x1.6 t83 aluminium 200mm overlap with 1000x40x1.6 T83 telescopic insert in top
The NQ is the tube I use in CL 5 chassis's ad the BQ is the favourite tube for the Minis, its supports 8.75m of unstayed sail

I'll get aphoto for you when its out next. The yacht ws always going to be unstayed, . It was essentially an expeiment in how far we can push the limits of our enginnering luck
We can and will go bigger

Here is a drawing made by an Argentinian friend ( Sebastian)

He measured the mast of the promo, french design.




It is divided in three parts: mast base, soft top and hard top.

( I dont know if this is the right way to describe the upper part of the mast.
Depending on the wind speed, you can exchange the upper section from a hard or stiff
part to a softer one)

Unfortunatelly, we don have acces to this kind of aluminium here. Too expensive.!!
regards

juan enrique

That doesn't sound too bad as far as mass goes. I had in my head that the airfoil mast section I've decided to go for was 12Kg per length, it was the thicker walled version (the length may have been the full 8m though, will have to go back through my notes). Great work with everything Paul, cant wait to hear about a bigger project in the future

Yeah, a bit hefty. The specs I gave above (~12kg) was for a 6.8m length. Its aerfoil profile, 165x55-60mm, alloy.

heres LPI's mast the ally top has the adjustable top. we find as the day progresses we need a longer mast,or if its warmer.

here it is in the bending tree. 2 branches are just the right distance apart for masts

i have a yacht called PIGS MIGHT FLY that has that Aclass section for the mast and use a rotaton control that was first shown to me By ROSS GAMLIN. as grumpy as he can be he is a very clever fellow and always good for a cuddle and he showed m a system he used on model yachts he built . after trying it out with the wing its the only system I would use. Be patient and next week I will drag the acht out and set it up for photos. the potential of the yacht is scary . Last time I sailed it she was accelating to 100kph in 150m before the roug salt and bad wheel balancing stopped further top speed

thats why i need to get it outlast time it was out the user left it at the ake and the bearings all got a bit rusty before I could clean it. She has been in semi retirement this year due to me being so busy. when I built it ,she was built as a yacht to intruduce people to sailing bodied yachts as opposed to the cl5/mini yachts. the main feature of the yacht was the back axle which is a 2m plank glassed. one of the ideas we had was to create a class of yachts where the only construction rules were
rule 1 . the main axle shall consist of a single 2m tube or plank.


there are 2 other yachts which have been built to this " rule". again the idea was to create some experimentation,and interest without huge expense. PMF is built of 100% recycled gear.
the 2m limit meant that a cl5 rig could be placed on the yacht or a stayed rig or solid wing added. If I ever get to building a wing I would build it to suit a yacht of this scale . With wheels added it would still be legal to put it on a trailer on the road without having to pull it apart
I only just fit in the yacht,but my older girls do sail it and have managed some high 60km speeds

here is a coment from the web about Bob

Howdy, One advantage of the lighter spunspar mast will be getting it up and down. I reckon that extra $500 or whatever will make the boat much more used. Not to mention the performance improvement.

Lightspars is at
#
Light Spars Of Australia
# Fcty 2/ 6 Horscroft Pl Moorabbin 3189
# (03) 9555 4622

Bob is a crusty old b*gger, but is kind hearted under the gruff exterior. The masts are available tapered (which is what you want) or untapered. They also have a hinged base available that allows the mast to swing down.

Michael.

Cheers
Aus 230

Bob supplied mast as per class 5 specs, 4 sections constant diameter

Vic , is that the mast that bent at all the joins or something else.? what was the price of a complete mast? I recall Travs mast sections being really tight so you had to keep them really clean at all time.
sorry if this sounds like I bagging out the tubing, It is good to know of other sources of tube as it all gets scarce