Bynorthsea asked for some more detail on our windsurfer mast extension mods so here goes.
My mast extension/reinforcing stiffiner is made from a piece of 48x4mm scaffold tube 1000mm long in this version I have salvaged the foot from a real mast extension (but im planning on changing this)
From left to right:
1, Adjustable collar, adjust up or down as you would a normal mast extension note retaining pin bellow collar (detail later)
2, Pivot and mount for boom (see pic 6)
3, Foot from old mast extension
View from other side
Slots in top compress to internal taper of mast
Boom fitted to pivot, boom just slips on, no retaining mechanisim
My next version will replace the old extension foot with this (same as Chook uses)
Using this will allow for change to downhaul tension while underway. (not possible with current system).
Detail of adjustment collar retaining pin.
The pins are 4mm long same as the wall thickness of the ally tube.
The pins support a collar of ally flat bar held in place with a hose clamp.
Excellent thanks very much, it's great to get advice and info from all round the world, not a lot of home building goes on over here.
Forgive me for not knowing the background of this - I assume this just slides onto a fixed pin on the yacht? What dimensions?
See the second half of this thread...
After the part where I tried and failed to support the mast with guy ropes.
Start from my post on "16 Jul 2016 page 1"
Here we are with the construction so far, tomorrow I take the angle grinder to a perfectly good mast step.
Interesting adjustable mast step A lot of stress on mast steps Any movement there and it will be noisy and get noisier. Those bolts will need to be done up tight ! Good idea for finding out what's best for tuning your yacht
I wanted to keep the length of the side plates as short as possible, the pin is also set at 5 deg rake to even out the movement. Here is the next stages.
I believe yours is the 3rd instance of this system so very interested to hear your reports and experience.
Looking really good there.
I would put 4 triangular gussets from the boss/base of the stalk, out to each of the top corners of the of the 2 vertical side pivot plates. Also a bit more steel to reinforce and stop the adjustment bolts buckling the base of the mast pivot, as there will be a huge load on the rear bolt.
I'd also make a dimple for the bolts to sit in to help stop them sliding out under pressure