With my boat, have noted 2 things that stand out . On a run the stern seems to stay well attached to the water(squats) and only nosedives @ the very top of A,but has no trouble sailing downwind with top boats of my fleet,& I donot have a good rudder design as yet,also have too much wetted surface on fin.The other, which is a problem.!! In light conditions when I tack the boat. it seems to sit uprite for several sec. before heeling & accelerating esp. @ bottom mark where I lose places, I try to do right things,tack slowly,bear off slightly crack main sheet slightly,but I always loose places to round bilge hulls. Any thoughts John

Originally Posted by GER 87

Are you bored seeing all this Lintel / BritPop / Cheinz and what have you thingies. Well now for something totally different than the current trend.

Check out the bottom posting in one of the German RC sailing forums : http://www.rc-network.de/forum/showt...m-22.04-in-USH

Comment from one of our top class RM skippers. Design is fast, points very high, neutral helm in the puffs and basically sails as stable as a well trimmed RM.

GER 87, do you have the contact details for the designer of this IOM?
I have a friend here in NZL who is very keen to acquire a set of plans for it.
Any help you can provide would be much appreciated.

Originally Posted by ronahearn

With my boat, have noted 2 things that stand out . On a run the stern seems to stay well attached to the water(squats) and only nosedives @ the very top of A,but has no trouble sailing downwind with top boats of my fleet,& I donot have a good rudder design as yet,also have too much wetted surface on fin.The other, which is a problem.!! In light conditions when I tack the boat. it seems to sit uprite for several sec. before heeling & accelerating esp. @ bottom mark where I lose places, I try to do right things,tack slowly,bear off slightly crack main sheet slightly,but I always loose places to round bilge hulls. Any thoughts John

Ron, thanks for the comments. Initially its hard to make an assessment without watching the boat perform myself. Therefore, im purely using my imagination to picture what is happening by what your saying.

When the boat is floated in the tank, is the transom sitting on top of the water, or is it immersed in the water. Ideally the transom should be sitting on top of the water. Adjust the lead ballast or internal ballast to suit.

Most IOM yachts will nose dive at the very top end of the A-rig.

I recommend that you use David Creed foils with Sofar, these foils are proven. Your foils might be the reason why the boat stays upright before heeling. In the UK Championship at Eastbourne 2011, we were competing on the final day in light wind conditions, I got myself back into A-Fleet and remained there with my boat.

I recommend you make the changes and then assess the boat again.

Picture
A wonderful finished product, built by Stefano Fasi (Italy)


JT

Thanks John, will float test, might have probs.with foils in oz.

Just a quick thought - if you have to much mast rake you can find the issues you describe occurring.

Tony

No the mast is less than 1 deg from vertical,weather helm is good,going sailing now, wind is light ,will investigate further , no doubt it will be simple when I find out why it happens .
Creers

Originally Posted by john m taylor

Picture
A wonderful finished product, built by Stefano Fasi (Italy)
Attachment 4871835

JT

Stefano Fasi??
The design of this boat is very similar to my XS Project !!!

Interesting the two boats do look similar, but on close inspection the hieght of the bows are different and looking at the 'hull rocker' of both boats, they are different too. But I know what you mean about the two boats being similar when you first look at them. Where does your 'XS' project originate from??

JT

Originally Posted by CaptainBit

GER 87, do you have the contact details for the designer of this IOM?
I have a friend here in NZL who is very keen to acquire a set of plans for it.
Any help you can provide would be much appreciated.

Hi,

sorry for the late response haven't been reading here for a few days.

The design is not available as a plan but only as a completed boat built to deck level. Having seen some of these boats and taking into account the skills, tools and time going into the build and finish of one of these boats, I strongly doubt that this would actually be anything for even a pretty skilled home builder.

Originally Posted by john m taylor

Interesting the two boats do look similar, but on close inspection the hieght of the bows are different and looking at the 'hull rocker' of both boats, they are different too. But I know what you mean about the two boats being similar when you first look at them. Where does your 'XS' project originate from??

JT

Born from my head drawn on my Pesonal computer 02-2011.This project by me later sold the team BOXER XS Ronconi ITA-39 Tancini ITA-59 Mazzini ITA-171

Many photos

http://www.flickr.com/photos/2868305...86498090/show/

I am going to be building a new rig for my IOM later this week when all the parts arrive. I have some T-9 11MM mast sections coming from Washington state. Anyone want to share their rig building tips? Planning on using clip on spreaders and terminating the shrouds where they attach to the mast instead of running shrouds all the way to the top inside the mast and having them attached to the mast head fitting.
That sofar design looks fast. Are there any of those boats in the US? Ryan

Hi , From Sofar AUS 65, I run H.Ten.10.8mm mast , Shrouds exit front of mast,fixed to masthead Chainplates 20mm back,clipon spreaders,no mast prebend.no prob. with forstay tension ,aprox 8mm round in main luff, & mast stows in box with no probs.Sofar,realy truck in a breeze, but I think I have Fore/aft trim Probs, Stern down 3mm ,reballisting and will give another try.

Originally Posted by Rssailor

I am going to be building a new rig for my IOM later this week when all the parts arrive. I have some T-9 11MM mast sections coming from Washington state. Anyone want to share their rig building tips? Planning on using clip on spreaders and terminating the shrouds where they attach to the mast instead of running shrouds all the way to the top inside the mast and having them attached to the mast head fitting.
That sofar design looks fast. Are there any of those boats in the US? Ryan

Whose sails are you using? You may want to ask the sail maker for his thoughts on how to build the rig.

I used to use one of those masts. Those masts are pretty stiff so I suggest you have the sidestays pretty low, about 500mm down from the forestay, and just have a hook with the stays connected at the front of the mast. I used 25mm of pre-bend but that may vary depending on whose sails you are using. With that mast section and 25mm of pre-bend you will have a lot of forestay tension if that is what you are looking for.

It is not easy to bend a 7075 T9 mast, you need an actual tubing bender to bend that material. I assume it is the Easton thick wall tubing.

I am using Vector sails. How would i prebend the rig? Where are you suggesting putting the spreaders? I am going to use one of those isobar headstay fittings.
Really hoping to get a rig where headstay tension is a non issue. Ryan

Originally Posted by Rssailor

I am using Vector sails. How would i prebend the rig? Where are you suggesting putting the spreaders? I am going to use one of those isobar headstay fittings.
Really hoping to get a rig where headstay tension is a non issue. Ryan

A good reference to use is this by Anders Wallin and Craig Smith (these are readerly available on the net)

And how to build a rig by Radio Sailing Shop
http://radiosailingshop.com.au/index...9337b4ba297311