Hello I have not been on this forum for quite a few years so I am not up to speed on any changes to the mini design. I recently acquired a lefroy mini from a friend (Harleyd) and I am in the process of rebuilding and upgrading it ( bearings, front forks,seat, etc.) I noticed Gizmo made a comment that when using unmodified windsurf sails the mast step works well with no rake. The mini I have was built with the original 10 degrees rearward rake. Is it worth considering modifying it to no rake as I do not plan to modify my windsurfing sails? I would like to be able to use my sails for windsurfing until I find the one I will dedicate to the mini.Would it be worth the trouble to change the rake? Would there be any benefit in performance either way? zero degrees or 10 degrees?
There's no simple answer to that question.
Depends on what range of sail sizes you plan to use, the design/age of the sails, the surface you sail on and average wind conditions. Andhow much work you want to do.
Have a look here...
www.seabreeze.com.au/forums/Land-Yacht-Sailing/Sail-making/Cam-batten-windsurfer-sails?page=1
And here...
www.seabreeze.com.au/forums/Land-Yacht-Sailing/Construction/Windsurfer-mast-extension-mods?page=1#6
Thanks for the reply. Most of my sails are camber-induced with a few RAF slalom style circa early 1990s. sizes ranging from 2.4 to 8.2 square meters. I would change the mast step to 0 degrees if I knew there would be a benefit to handling or speed. It would be easy to change it now at this stage of build versus after the rebuild is complete. I just don't know if I would notice any change as I have yet to sail a mini anyway. I anticipate experimenting with different sail sizes until I find the size most suited for average conditions.
If you have a fixed mast position and angle then I would select the sail you will use most and align the centre of effort to a point around half way between the loaded balance point and the rear axle.
Obviously switching between a 3m storm sail and a 9m light wind monster will shift the alignment of your centre of effort quite a bit. Hence our move to adjustable mast bases for wind surfer sails.
We tend to run our bigger sails vertical and the smaller sails with quite a bit of rake.
If I decided to make the rake adjustable would 0 to 10 be enough range? I would guess the mast angle doesn't have to change much to move the CE quite a few inches. I think I will use a sail that is in the five to six meter range. I have ten sails to choose from, so I like the idea of finding one that is good for light wind and one that works well in strong wind. If that means making the rake adjustable I might consider doing it.
These pix should be fairly self explanatory.
4m sail on a mini with 25-30degrees of rake
7.2 m on class 5 vertical but with adjustable base set back (away from front wheel) as far as possible along range of adjustment.
5,2m sail with about 5deg rake and base in the middle of the range of range of adjustment.
In short I if you go adjustable I would advise 20 to 25 deg back and 5 deg forward for those realy big sails.
Thanks for the input. I want to go adjustable for sure. I hate driving all the way out to a place to sail then find out I am not set up properly for the wind conditions. Any pics of good adjustable designs?
Already posted tons of pix of adjustable design. See my 1st post on this thread.
Look here- www.seabreeze.com.au/forums/Land-Yacht-Sailing/Sail-making/Cam-batten-windsurfer-sails?page=1
Start at my post from 16 Jul 2016 about 2/3 of the way down 1st page.
If you read ffrom the beginning you will se that I started by playing with the idea of supporting the mast with guy rope. That idea failed miserably but the system described from 16 Jul 2016 on is working very well.
I can see now is the time to make this modification to my mini. My frame is still unpainted and this will be an easy add. I like that your design lets you move the step back and forth as well as the mast angle. Thanks again for all the information. I will post pictures before I weld it together just so I don't mess it up.
Sorry for the lack of a close up pic. There are a series of holes along the bottom of the mast holder, and the top is adjustable by lengthening or shortening the all-thread. I made this for a class 5 sized rig, and I'm able to change rake, and move the mast fore/aft depending on the size of the sail.
These are old pics, but I also lowered the tab on the mast support to a lower point (second pic), keeping the all-thread closer to level with the ground.
The last two pics are a similar setup on a big fat tired mini... Just for stimulating your imagination.
Make an adjustable JHS mast step. That way it doesn't matter where you mount it on the chassis and you can tune the rake for your available sails.
Front end slides out= sail too upright/CEO too far forward
Back end slides out= too much rake/CEO too far back
Having adjustable gives you the flexibility to tune your yacht to your unique sailing style.
As you can see there are various ways you make an adjustable mast base with some more complex than others.
I found the JHS base the simplest to build and use.
Draw it, make it, break it, then make it stronger.
Ben.
Good advice. Sometimes (most of the time) I tend to overthink things to the point it never gets done. I will definitely go adjustable. As with many things I'm involved in I can turn a simple rebuild into a major overhaul and modification project but, wheres the fun in fixing something without improving it?
Select to expand quoteBenBoulder said..
Make an adjustable JHS mast step. That way it doesn't matter where you mount it on the chassis and you can tune the rake for your available sails.
Front end slides out= sail too upright/CEO too far forward
Back end slides out= too much rake/CEO too far back
Having adjustable gives you the flexibility to tune your yacht to your unique sailing style.
As you can see there are various ways you make an adjustable mast base with some more complex than others.
I found the JHS base the simplest to build and use.
Draw it, make it, break it, then make it stronger.
Ben.
JHS?
