Hi Row,
The block you have seen is very old and used in the past for RG65 Jib.
I recovered also the block used for RG65 and AC100.
The profile is obtained with a “chosen” section of an elliptical form as depicted in the sketch. No NACA profiles used.
Cheers
Claudio
Sail making !
First I made a trial with a green/gray tissue used for kites. Just to restart learning how to use the block. See sequence of operations : the first 5 pictures refer to the joining of two adjacent panels.
Then I toke the Melinex 50µ for the first time.
The pictures 6 to 10 show the jib assembled and the integration of the fore-stay cable.
I will try tomorrow with a lighter mylar.
ClaudioD
say it aint so…claudio, not using the claudio tool…
so what naca shape makes up your sail block…
I was going to ask that, then I wondered if it was a different Claudio…
To Marc & mrpenguin,
answer given at post 140.
For me, sail shape are not made in accordance to any NACA profile.
Personally I use an elliptical figure dimensioned to the sail size . Only a segment of that figure is used. The parameters are :
chord, draft and draft position in percentage.
To determine the block curvature, other then the ellipse, it is also used the Piano Wire and seldom the Hyperbolic Spiral shape : see below
For me again, the Piano Wire curve is probably the best shape that meet most closely the Sail curvature under wind pressure.
Cheers
ClaudioD
New Years Greetings Claudio,
I’m guessing the question on peoples mind is: why are you using sail blocks instead of the famous Claudio tool for making sails ?
Cheers Alan
Hi Alan,
Best Greetings for 2013.
Personally I like blocks, the Claudio Gadget I don’t remember where it is !!
Just finished the the Main with the 50g/m² Mylar , = 6g similar as the Melinex one
Was a pleasure to make it !
Below the new Main building sequence :
Cheers
ClaudioD
Another set of pictures for the new Main :
ClaudioD
Jib one single sheet, but with a carbon rod of 2mm as luff.
This could reduce sagging !
The Jib weight is increased to 6g !
The Full Rig is now 35g, 10 g more then predicted at the budget
Final weight ESTEREL Footy is 546g, 35g more then the Design calculation.
Without modification to the Bulb, the boat will sink by 1.59mm from the nominal LWL and water plan.
ClaudioD
Claudio, what NACA profile for the blocks?
Great thread Claudio, I am really enjoying it.
Terry
Marc
I have already answered the question at post 140 and 144.
I don’t use NACA profiles !
The Piano Wire is the easiest way to define a profile !
Cheers
ClaudioD
I’m pleased Terry, thank you
Cheers
ClaudioD
sorry claudio, I complete glossed over those posts…thanks for the redirect… makes sense…
Don’t mind Marc,
you should try the piano wire on a table and forcing the bent with 3 spikes as depicted in a drawing above.
You will be surprised how easy is to simulate a sail profile. Similarly with a wooden strip.
Cheers
Claudio
makes sense… since I have a CAD program and 36" plotter putting the plans and printing out in full scale from a NACA form is also easy. but sometimes Simple is best. I have a tendency to overthink things from time to time.
do you have multiple sail blocks to allow for different shapes?
Marc,
I have made 3 blocks that I used for RG65, AC100, AC120, Class M, Esterel 123, and are valid for all boats from 50cm up to 150cm.
I have a fourth small block that I used at the time of the Guinness Record and used again this week for the 3 panel Jib as visible on above pictures.
Here some pictures about the blocks and paper sail sample as well the first made ac100 sails.
Cheers
ClaudioD
sorry to hijack the thread, thanks for the pics…
It can be useful to recall certain things.
Today I do have extra work, one ball bearing of the house vacuum cleaner lost some balls !!! Ball bearing type 608 RS, very standard also with rollers !! Of course it break when the 1 year warranty was over by 5 months !!!
Started selections of rings to fix the Main to the Mast.
Narrower ones force to the luff to stay close to the mast, wider ones may offer better performances since the mast is more away from the luff.
Which ones ? This is the question !
Cheers
ClaudioD
PS : Added pictures with large rings
60 days later the ESTEREL Footy is almost finish !
Left wet sanding and hull paint.
ClaudioD