A couple of IOM yachts

[Eddie LancasterParticipant @eddielancaster]

Had a good mornings sailing today, the boat was very slow and sluggish to begin with, but things started to improve as I tweaked various things, I have made a new jib boom so that I have finer control of the slot, I have also put some pre- bend into the mast, for some reason it was not needed on the Boxkite, but it created diagonal creases in the mainsail, but I did manage to eliminate most of them after some more tuning/fiddling, after that things got better and she was as fast as the other IOM on the water, so mission accomplished .

The next job is to make a new mast from lightweight Ali tube, the current one is made from tube bought from B&Q and is very heavy, the total A rig weighs nearly 400 grams.

Regards.

Eddie.

Edited By Eddie Lancaster on 15/04/2021 14:00:32

[Eddie LancasterParticipant @eddielancaster]

I have now made a set of rolls to put the pre-bend into the mast.

The mast has 14mm. of pre-bend and follows the luff of the mainsail, it is only fixed at the top and bottom at the moment , there are no luff rings fitted.

On the water with very light winds and the sails are setting much better than they did.

Regards.

Eddie.

[Tim RoweParticipant @timrowe83142]

Hello Eddie

Slipping along very nicely. Great photos and great mast bending tool.

I am intrigued. Which way are you bending your mast? In the relaxed state does bow forwards or backwards in the middle?

It was a bit too windy for a trial sail of the Boxkite at the weekend. Hoping to have better conditions this weekend.

Tim R

[Eddie LancasterParticipant @eddielancaster]

Hi. Tim, thanks for your kind comments, the mast is bent back to suit the luff of the mainsail and is only bent from the middle mark down about 400mm. the top of the mast from the middle band is straight and the bottom is left straight, I was sailing In very light winds with no tension on the backstay and the mast upright and relaxed. The sails that I am using have around 8mm luff allowance.

If you go onto Frank Russell’s website he has a free downloadable information sheet with a lot of tips on setting up the Elipsis.

Regards.

Eddie.

[Tim RoweParticipant @timrowe83142]

Hello Eddie

I will check out his setting up tips.

The reason I asked is that all the information I have seen to date is that the pre-bend is in the opposite direction and important for the A Rig so that you can get sufficient forestay tension. In light winds the backstay tension puts the mast straight and at the top end of the A Rig range the backstay tension is increased to flatten out the luff allowance and twist off the the top of the mainsail to de-power it.

Interesting to see what Frank says.

Tim R

[Eddie LancasterParticipant @eddielancaster]

You had me a bit worried there Tim, I had to look at some more information I have, written by an American sail maker, he says “success in sail setting requires an understanding of the match between the flexible sail and its mounting componant, for mainsails, the mast shape must be matched to the shape of the mainsail luff”. He doesn’t mention pre-bend though. All very interesting stuff.

Eddie.

[Eddie LancasterParticipant @eddielancaster]

I was right to be worried about my mast pre-bend, I have now found and downloaded an idiots guide to rig tuning, it gives a full description of the correct mast pre-bend which means I have to do something about my mast.

Luckily this boat is only for fun so no real harm done, and I have l learnt some more along the way before I tackle the Elipsis.

Eddie.

[Eddie LancasterParticipant @eddielancaster]

Had another good morning boating, over three hour’s, I have now got the pre-bend the right way round, facing forwards, but I do have to put a lot of pressure on with the backstay to get the mast to match the mainsail luff, the boat was nicely balanced, sailing on it’s own without having to use the rudder until the next tack, just need to keep sailing now to improve my skills and to tweak the boat.

Eddie.

[Tim RoweParticipant @timrowe83142]

Excellent news Eddie

Tim R

[Eddie LancasterParticipant @eddielancaster]

At last I have finished the paint job on what started out as the first Nimbus hull to be built.

It has only taken five months to get from the bare hull to this stage, most of the time was taken waiting for the right conditions, at least 18 deg. C and no wind, more time was spent with the hull hanging in the workshop letting the paint dry and harden fully. It just needs fitting out with the winch servo and radio, and the mast and rigging fitted.

Eddie

[Tim RoweParticipant @timrowe83142]

Spectacular job Eddie

Very well done.

Tim R

[Eddie LancasterParticipant @eddielancaster]

Thank you Tim, pleased that you approve.

Eddie.

[Bob Abell 2Participant @bobabell2]

Eddie

Very nice hull,

If this is the Bantock Nimbus, I don`t remember the roof shaped deck?

Just curious and forgetful

Bob

[Eddie LancasterParticipant @eddielancaster]

Hi. Bob, thanks for your interest. The hull below deck level is Nimbus 3, but the foredeck is from Graham’s Boxkite as I didn’t like the totally flat deck of the Nimbus, so it is a hybrid, or should that be mongrel?

Best wishes.

Eddie.

[Eddie LancasterParticipant @eddielancaster]

On the water at last.

Not a lot of wind, but when there was a puff she made the most of it and accelerated away.

The bare hull weighed 1000 grams and with all the radio battery and sails fitted ready for the water she was 4050 grams, which I was quite happy with.

Eddie.

[Brian White 3Participant @brianwhite3]

Hi Eddie,

I've recently been given the plans for the Nimbus Mk3 and have made a start with constructing the building board. I had a few 1mtr lengths of mahogany 10×3, so have used these for the inwales. I used two pieces of 5 x3 mahogany side by side to form the centre keel and then realised I have to overcome the problem of how to lay the planks at the tip of the bow. Can you advise me please, are these initial planks twisted or left flat and then chamfered back. Maybe you have a picture head on before you painted yours that may help explain this tricky bit?

I've started a new thread 'Nimbus MK3 Build' so I can share my progress. It was Ray Wood who directed me to you in response to my thread. Seems you move in similar directions to me. I've nearly completed my 1:8 Scale Veronica and sailed on SB Cambria in the Medway Barge Match this year.

Perhaps you could help me wrt a suitable winch and servo?

Best regards, Brian

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