New AR15 - for Larry

Post by **jacquesmm** » Fri Sep 06, 2002 2:59 pm

In reference to the R550 thread, attached are some sketches of the hull of the new boat. It looks like our R550 but it has less rocker and the bottom panel is wider. I was very, very tempted to design something in the style of the NZ Javelin shown at: http://www.javelins.org/Technical/virtu ... htm You feel the speed just by looking at it! We briefly discussed the Javelin in an email exchange two years ago but I forgot that you had built two. You are correct about the bottom panel: it must be a struggle to shape them. Our design will be not only easier to build but easier to control under spinaker. Note the low chine forward: I wanted to avoid slamming, have a sharper edge going upwind and it will be well above the water with the crew on the trapeze, planing: no bow steering if the crew knows what it is doing. 140 sq.ft of sail! I am excited about the design and may want one for myself.

LarryA · Post by **LarryA** » Fri Sep 06, 2002 4:36 pm

I pulled my rhino models of the Javs I built and kinda played around with them a bit. It is very hard to really get a feel for AR15 shape.. But from the looks of it, my only comment would be that the upper chine SEEMS (because I can´t really tell for sure) to turn up a bit more than I would have expected during the aft run. The way you have it, it seems you are trading off some downwind planing performance and stability for upwind/light wind performance. It looks like there may be a little twist to the deadrise (again could just be the views). The bow also looks like it should help avoid nose dives a bit - seems a bit fuller than mine..... The virtual javelin is a really nice documentary about a really high tech jav (vacuum bagged glass or kevlar can´t recall over pvc core). Mine is a little wider particularly in the bow and the aft sections with a little less rocker - its a six year old design versus the Virtual Jav which is about 2 years now I guess. [ This message was edited by: LarryA on 06-09-2002 16:46 ]

Post by **jacquesmm** » Fri Sep 06, 2002 5:03 pm

<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD>Quote:<HR></TD></TR><TR><TD><BLOCKQUOTE> On 2002-09-06 16:36, LarryA wrote: I pulled my rhino models of the Javs I built and kinda played around with them a bit. snip .. But from the looks of it, my only comment would be that the upper chine SEEMS to turn up a bit more than I would have expected during the aft run. The way you have it, it seems you are trading off some downwind planing performance and stability for upwind/light wind performance. </BLOCKQUOTE></TD></TR><TR><TD><HR></TD></TR></TABLE> Yes, for that reason and for "docility" under spi. I wanted a boat that would altogether not scare a beginner but be fun for an experienced sailor.

Post by **jacquesmm** » Mon Sep 09, 2002 1:35 pm

After thinking about the whole week-end, I lowered the chine. Thanks for the advice LarryA. I was at a small local boat show talking about compromises with the people that make the Raider: how much performance should we compromise for ease of handling at low speed. The Raider doesn´t make such compromises and is considered as a good beginner´s and performance boat. That high chine at the stern was a weakness on plane, I could almost feel the lack of power when thinking of it.

LarryA · Post by **LarryA** » Mon Sep 09, 2002 5:41 pm

Glad I could contribute. Not sure I would call it advice as much as just a suggestion

JimW · Post by **JimW** » Wed Sep 11, 2002 8:17 am

Jacques, How close to the Coronado 15 is the new AR-15. I rented and sailed the coronados for a while at various navy base sailing clubs. They seemed to have very large sail areas too. The foot of the jib was low and always wet and getting heavy spray. Very difficult to see around the sails while piloting. They seemed like a rocket ship to me. That was before I bought my hobie 16. <IMG SRC="images/forum/icons/icon_wink.gif">

Post by **jacquesmm** » Wed Sep 11, 2002 9:33 am

<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD>Quote:<HR></TD></TR><TR><TD><BLOCKQUOTE> On 2002-09-11 08:17, JimW wrote: Jacques, How close to the Coronado 15 is the new AR-15. </BLOCKQUOTE></TD></TR><TR><TD><HR></TD></TR></TABLE> Close in dimensions but much lighter and a better hull. If you want to see under the jib, use a smaller one and go slower! Sorry but there is no miracle there: if you want the sail area and speed, you need that kind of jib.

LarryA · Post by **LarryA** » Wed Sep 11, 2002 10:16 am

Not so sure about the seeing under the sail problem. My Jav sails are made of Dimensional Polylant (think that is the name of the stuff). It is clear (mylar) with reinforcment built in, can see past them (through them) no problem.

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