Rudder trunk remade…
Details : carbon and brass tubes staggered togheter and glued with loaded epoxy.
Just to shows the alluminium edge appearing under the carbon. The trailing edge is very sharp like a knife blade. One (me) I should pay attention !!
Claudio
Just cut out a dummy cockpit layout
This floor will be made out of balsa sheets of 1.5mm doubled with glass cloth of 50g/m² on both sides.
Claudio
Grande Caludio sei un mito!!!
Guarda che il 1° maggio è la festa dei lavoratori…
Tiziano,
tomorrow RéArtu and company we will try to put in the water the first AC120 / SUI-100 - New Generation.
Since a few days is almost impossible, the wind is blowing at an average of 15-20 kn with gusts up to 35-37kn. West wind called Mistral on our coast.
Forecast announce 6-8 kn for tomorrow at 14.00, South-West wind.
1st of Mai - resting ? who knows !
Ciao
Claudio
completed the carton mock-up
All is ready to start sandwich balsa/glass lamination for the deck and balsa/glass/kevlar for the cockpit. Kevlar !? just to give a color appearance.
Claudio
I tried two options and finally I choosen the wooden one for various reasons : easy to be made out of 2mm thick plywood and because the rectangular box may be used for another purpose that I will illustrate for comments.
The wooden box will be coated with epoxy resin inside and carbon/epoxy outside.
The fin shall be adjustable in height of about 3cm in order to change the lenght from 48cm to 51cm as function of wind pressure *.
Claudio
Preparation for the cockpit floor composed of a sandwich balsa-kevlar-glass -epoxy
Kevlar cutting is always a problem, therefore I use adhesive paper tape to mark the borders and than using a cutter. Scissors only of very good quality and expensive may help !!
This plastic sheet will produce a very ‘glossy’ surface
Anything is good to make weight !
Claudio
It was supposed to be glossy with the use of plastic sheet of 1mm, the same as used for painting/posters frames with one antireflection face.
The other face with the use of a polyane film (garbage bag)
Claudio
Is time to talk about budget and verify if the overall situation is in hands !
This is the actual analysed budget :
Let see the actual measured weights :
The allocated weights are extracted from catalogs except the Rig that is just extimated from previous similar designs.
Claudio
This subject is not very often discussed, but very critical !
My laminations, once polymerised, are presenting a surface plenty of holes due to to the tissues weaving.
These macro pictures are taken with an enlarging lens in front of my camera.
The n°1 refers to a part of the Fin surface after wet paper sanding. Some few holes are still visibles.
The n°2 - not all the Fin surface look the same everywhere !
The n°3 is taken on the rudder after having coated with a white precoat. After wet sanding , the holes are filled up.
The lesson learn !
If a carbon appearance is choosen, then the holes can be ‘filled up’ with various layers of paint or resing coats until the holes disappears. Sanding after each coat is necessary to observe the progress with a magnifier lens. Polish at the end is necessary toreduce roughness.
If the final aspect is a colored paint, then several layers of pre-coat are needed like the one used for the rudder above and then applying the paint and polishing after.
This phenomenon is also present on the hull of course. Same problem, same remedy.
Once I was discussing about “roughness”, the above images are a tipical example of what should be avoided !
According to my readings, a boat around 1.3mt length and with narrower fin and rudder, the surface roughness should be lower then 1µ. Tipical car body paint is around 5µ.
Honestly, I do not knows how to get such roughness caracteristics !!!
Any comments about ?
Cheers
Claudio
I remember reading something in Lester’s onemetre.net site about this subject.
http://www.onemetre.net/Design/Roughnes/Roughnes.htm
Nick
Nick,
in fact this was one of my readings.
It is not my intention to go out of topic, therefore I just make this simple remark.
This subject is not discussed very often, actually there are two approaches, the ones wich use to finish the hull with a grade 1200 paper to increases roughness and the ones that search for the best achievable smothness polishing as much as possible.
All above are referred to the construction capability for the surface treatment as depicted above.
Cheers
Claudio
Start fixing the Fin Box & Floor supports wedges
Claudio
Checking vertical alignments of Fin and Rudder before definitive lateral support lamination.
Horizontal control with bubble level.
[img]http://img14.imageshack.us/img14/8165/c143n.jpg[/img]
My reference are the trailing edges of both elements clearly visibles in these two pictures
Claudio
After reviewing the various construction details for the servo’s supports and ancilliary items, like pulleys positions, I’m back to the model construction :
Searching the best position for the servo arm assuming the swing angle of 100°
and the mounting accessibility.
Almost "OF TOPIC"
This is the cotton fabric that I will use for the next boat
Claudio
cycadellic material…
should look very cool.
Hi Robert,
Nice work seen on your site !
The tissues are simply a Batik style cotton fabrics generally used for quilting. An example may be found here : http://www.quiltknit.com/fabrics/batik_fabric_9.htm
I just proposing a way to have a personal ‘original touch’ decorating his boat with colorfull cotton cloths - It may be a new fashion ? why not !
Avantages : as sandwich assembly, it partecipate to the lamination strenght of the boat and at the same time providing a decoration not achievable with classic painting that is not needed anymore.
Claudio
Some others pictures of the work
The definitive Deck Layout.
The preparation for the fairlead
Claudio
Deck layup
Waiting for 24 hours !
Claudio
Beacause of the little access due to the mast Bridge solution, I decided to insert the servo arm already fixed on the carrier. This drawing shows the mounting sequence.
The arm is screwed on once the servo is inside
I like some times to make the life complicated !!
The servo arm carrier
Claudio