Nzl-20

Hi Pete,
NZL-20 still in stand-by since removal. Searching for a new lab !!
By memory real AC:
Loa 24mt
Lwl 19mt
Dspl 24T
Bulb 20T
You ca deduct the rest.
Real scale produce a very low DSPL and some time impossible to construct the model. i.e. AC120
scale factor 1:20
Model Dspl = real Dspl /20x20x20 = 24000kg / 8000 = 3kg
Assume a bulb of 20000kg /8000 = 2.5kg tghis give a margin of 0.5kg to build the full boat = mission impossible !!!

Of course it is not necessary at model level to use a ratio between boat and bulb of 83%

70% is necessary to warrant good stability of the model, therefore 3000 x 70% = 2.1kg in the bulb and 0.8kg for the construction = again mission impossible !!.

CD

Thank you Claudio, Great information , NZL-20 is a beautifull Boat. In the first set of drawings you have for her , you show the tandem Keel with a wider beam , Do you have a drawing of the frame’s to go with it ? I may consider building her instead

Best Regards,
Pete

Hi,
Alan and I we have disregarded the model with twin fin for two reasons, AC120 Rules observation and not sure that will work at model level… who knows anyhow !!
Best regards,
CD

Here the set of plans :

Thank you Claudio, I definitely have a choice to make . I realy appreciate all your help

Best Regards,
Pete

Hi Peter,
to complicate your choice, eheheh ! I noticed that there is another model the “Areva” that collected various excellents results at National regattas. See plans and pictures at :

http://www.nonsolovele.com/2013Plans.shtml

Of course everything remains with the thumbs unless you are sailing a shoe box !!!

CD

Thank you Claudio, I am thinking that I am leaning toward BMW ORACLE , I have a question I was looking over the plans that I got from Renato Chiesa site , it does not give me the frame spacing , is it the same as set up as NZL-20

Best Regards,
Pete

I don’t think so, his project uses 16/17 shadows, but you should ask him for details.
CD

Thank you Claudio, I will do that , I do like the NZL-20 has anyone finished building her ?

Best Regards,
Pete

No ! but do not make any serious difference with an Areva or SUI 100…
CD

Pete,

I do have a couples of questions for you :

Where are you sailing your models - close waters - open waters ?
What is the average wind speed over the year in these areas ?

This is very important in order to define the most suitable Prismatic Coefficient

CD

Hi Claudio, There is a lake by my house ( open waters )where I sailed my Herreshoff Buzzards Bay 14 ( no Radio ) she ‘s built at 3/4" = 1’ - 0 " the other spot is a man made pond . that is where people with RC boats sail.( close waters ) average wind speed is 5 to 17 knots. I talked with a few people that sail there and the largest boat is 36" (914.4 mm ) they had never heard of the IACC 120 Class . Most of those boats are plastic kits . could one of your boats be scaled down to that size ? and still give the same performance ? I completed the Herreshoff at the beginning of the month (july ) here are a few photos of her on her maiden voyage

Best Regards,
Pete

Hi,
by average I was intending how many days a years the wind is blowing at 7kt and how many days a years is blowing at 17kt.
Below 8-9kt it is possible to choose the more efficient CP.
Actually my models are designed around a CP of about 0.58. Probably a CP of 0.54/0.55 would be better below 8kt wind speed !

About classes, other then the AC120 I developed in 2007/2009 does exist already the AC100 that is just 1mt long that I designed in June 2009. Several drawings are available in the Amon site I passed to you before. A non skilled modeler should not choose the AC100A since the displacement is too low to allow an easy construction. in 2010 I designed the AC100-B that is somewhat easier with composites materials, AC100-D and AC100-U are for wooden veneer construction.

these films where taken at 3/5kt for my first AC100B

https://www.youtube.com/watch?v=R4MM_z_q3aI
http://youtu.be/_UWjuL5hQ_Y?list=UU7laodmU4RCck0owTn2uXjA
http://youtu.be/EdyHr9nLUYY?list=UU7laodmU4RCck0owTn2uXjA

CD

Hi Claudio, After watching the Videos, the wind speed in them looks to be about the same wind speed as around here. I will look into the AC100 Boats , I thought I had this all figured out , Now I will re think this . I did enjoy watching them sail

Best Regards,
Pete

The video shows only one AC100-B, the first ever made, the others around were RG65.
CD

http://youtu.be/UggSPHMYwRk