Question for the tech types .
I have a 100% Carbon 460 North mast that I am thinking of cutting 30cm off the base to make into a 430 . Simple enough .
My question is, is this pretty much what all 430 s are anyway .?
If I do this will I need to reinforce the base or is it the same thickness 30cm up from the original base anyway .
My other thought is will the boom reinforcement area be pretty much reduced by 30cms also ?
Then the issue of bend #'s .
Anyone else tried this ?
Thanks for any thoughts .
i mad that mistake and found out that my mast base would fit inside the mast ... duno how u could check that but some thing to think about
Usually the 460s are stiffer than 430 and when you chop the mast it gets a bit stiffer again.
But you can check it yourself.
I lay the mast on blocks between two benches and hang 30kg (gym weights are good) on the mid point and then measure the deflections at 25,50 and 75%.
You can measure your 460 before cutting, by supporting it at the 430 point to see what you are going to end up with.
My set up looks pretty mickey mouse but gives the same figures for stiffness and bend character as the manufacturers and it is sure good enough for comparo.
I've made many good usable masts out of older stuff I've had laying about, particularly 400s and 430 just as you plan.
Best 400 I have is actually 409 and made from a 430 prototype.
Thats another point. You often don't need to shorten to 430 as you can add the usual mast base extension to the length also.
ie my 5.1 uses 9cm extension so made the mast 409 and now use zero extension.
If you fish about on the net you can find the calc methods for masts or send me your email and I'll send what I have.
how about a trip to the sail maker and a strap/cup placed at the head on your smaller sails?
I have a 460 that suits my 4.7, 5.5, (both with cup /straps) 6.6, 7.5 and 9m (thats with an extension on top ie. a vacuum cleaner tube bashed into shape)
one mast means less gear, less money and less hassle.
Hey Thanks for all those thoughts . Really helpful all of them . Now wheres that hacksaw ! or should I go to the sailmaker ......
With most smaller sails it's not very satisfactory to run them on a longer, stiffer mast with a head strap extension. They will feel rigid and twitchy. You are effectively running them on the stiffest part of an already too stiff mast. Do the hacksaw job on the other mast. ![]()