A couple of IOM yachts

[Tim RoweParticipant @timrowe83142]

Well it passed the strength test Eddie!!

Ray and I are still intrigued about your method of producing the sunken aft deck.

Tim R

[Eddie LancasterParticipant @eddielancaster]

Hi.Ray and Tim, the rear deck developed from my original thoughts of a flat bottom and two sloping sides, with square corners but I thought rounded corners would look better and be stronger.

Regards.

Eddie.

[Chris FellowsParticipant @chrisfellows72943]

I was thinking the same, must be some weight on there!

The sunken deck certainly does look better with rounded corners to echo those of the hull and no joints to worry about.

Chris

[Eddie LancasterParticipant @eddielancaster]

Hi Chris, and Tim as you raised the point I have checked the weight, there is a total of 12.6 kilograms on there.

Eddie.

[Eddie LancasterParticipant @eddielancaster]

The rear deck is now fixed in place.

I have put the Rx high up on the foredeck frame,this will keep it out of any water that may get into the hull, and allows the arial to be placed as high in the boat as possible.

The foredeck can now be fitted, with plenty of tape etc. to hold it in place while the epoxy hardens.

Regards.

Eddie.

[Eddie LancasterParticipant @eddielancaster]

The two hulls are now ready for finishing, I just need some warm weather so that they can be sprayed.

Regards.

Eddie.

[Eddie LancasterParticipant @eddielancaster]

The first Nimbus hull is almost finished, the spruce planked one, only the rigging attachments to be fitted, and I may paint the transom and lower rear deck white.

It is hanging from the light fitting until the lacquer has fully cured and it can then be put back on its stand.

Eddie.

[Eddie LancasterParticipant @eddielancaster]

The lead bulb has been cast, but not in a closed mold as I was plannimg, it would not hold the moulten lead,it all ended in the baking tray that the mold was in,so it was back to my usual method of casting in two halves and joining them together with epoxy, a bit more work but I still get a lead bulb.

The gauging rings are the ones that I made to finish the pattern to size, the bulbs as cast came in at just over 2.5 kilos, so had to be pared down to allow for the weight of the fin.

I use a small Surform to remove the excess lead,it shaves it off in small pieces of swarf, and leaves a good finish, I always wear gloves and a face mask when doing this job and get a coat of primer onto the raw lead as soon as possible.

The spruce built hull has now had all the deck fittings put on and the closed winch line fitted,I have left the spare line on until the mast and sails have been rigged as I am not sure how much travel will be needed and I may be able to shorten the lines and get a longer piece of elastic to tension the lines.

Regards.

Eddie.

[Tim RoweParticipant @timrowe83142]

Very nice Eddie

The information I have is that you need 270mm of winch travel. The Hitec I have in the Boxkite delivers 3 1/2 turns which is far to much so as I have a Spektrum Tx I had to use the Travel Adjust function, Other makes call it End Point.

Can't weight to see them on the water.

Tim R

[Eddie LancasterParticipant @eddielancaster]

That’s the same winch that I am using, I have now got the mast and sails rigged, using the endpoints I’m down to less than 50 percent of total travel giving nearly 290mm, I will see how she sails tomorrow.

Eddie.

[geconParticipant @gecon]

Impressive lead bulb Eddie. Very nice work. The hulls look like they'll rocket along, unlike what some of us, i.e. gecon, are producing!

George

[Eddie LancasterParticipant @eddielancaster]

Thanks George, I did have her on the water today and it looks promising, need to put a bit more pre-bend in the mast as the leach of the mainsail is binding on the mast, I also have to lengthen the jib sheet, I hadn’t enough adjustment to give a wide enough slot, so get those fixed and we should be on our way to a fairly fast boat.

Regards.

Eddie.

[Tim RoweParticipant @timrowe83142]

Congratulations Eddie

Tim R

[Eddie LancasterParticipant @eddielancaster]

Thanks Tim.

Eddie.

[Eddie LancasterParticipant @eddielancaster]

As it was a fine day with light winds,I had to take the boat out again to see if the alterations I had made had improved her sailing. she appeared to be better but I will know more on Thursday when I can sail against another IOM.

Eddie.

[Tim RoweParticipant @timrowe83142]

That must have been very satisfying Eddie.

It was for me, just looking at the photos.

There are lots of good tuning tips for IOMs on the web. Two really important features are to have sufficient twist in the mainsail and associated twist in the jib due to the wind gradient. A lot of people sail with two much vang. The second is the relative sheeting angles between the main and the jib. A good starting point for going to windward is the end of the main boom being about 10mm off the centreline and the jib sheeted further out. On the jib for the Nimbus the end of the jib boom will probably be roughly half way between the mast and the shroud. You can control the twist of the jib to adjust the slot using the jib boom topping lift. You will know when you are hitting the sweet spot when it feels like the turbo has cut in!

I must get the Boxkite on the water soon.

Tim R

[Eddie LancasterParticipant @eddielancaster]

Hi. Tim, yes I was very happy with it today, I have looked at YouTube videos and read various articles on tuning and they all seem to have different ideas of what are the correct settings, I suppose each boat, even to the same design is going to be different.

This boat was never meant to be a racing boat, I just liked the hull shape and the fact that it was easy to plank, the first one with balsa and this one in spruce just for the looks.

The balsa hull will have racing scrim sails and thin walled lightweight aluminium for the mast so hopefully will be a lot lighter, I may have to put a faster winch servo in it as well, the Hitec is a bit slow.

Another thing I need to make is a tool to get the pre-bend of the mast right.

I will keep you posted on progress.

Eddie.

[Ray Wood 3Participant @raywood3]

Hi Eddie,

Your IOM boat looks great, tuning is an art, I took my little Dragon Force RG65 to Eastbourne MYC and in 5 minutes the experience guys set the boat up to go fast

Or just pop out to see Tim ?

Just looking at the commercial prices of ready made fittings, wow looks like there will be some metalwork coming up !!

Did you weight the bare hulls of the Balsa versus the Spruce ??

I fancy Mahogany when I can get to a saw bench, what thickness are your planks ?

Best Regards Ray

Edited By Ray Wood 2 on 13/04/2021 16:16:44

[Eddie LancasterParticipant @eddielancaster]

Thanks Ray, the Spruce hull with servos, battery and receiver but without the keel and rudder weighed 1.36 kilograms, the balsa hull fitted out the same weighed 1.120 kilograms, not a lot of difference, but the balsa hull has more glass fibre and resin, the thickness of both is 1/8” I suppose I could have used 2mm for the Spruce one, Lunt then it was never intended to be a racing boat.

Regards.

Eddie.

[Tim RoweParticipant @timrowe83142]

Hello Eddie

It is interesting to note that the closer you get to the front of a fleet the differences in tuning become minute. Good starts, light touches on the helm excellent tactics then make all the difference if applied consistently. Plus of course the hunger to win.

I think it was Malcolm who may have said if you have two yachts on the water you have a race. That's true even if it stays in your head.

Looking forward to comparing notes on the Ellipsis.

What made you choose that design. I am curious.

Tim R

[Eddie LancasterParticipant @eddielancaster]

Hi. Tim, there are only two of us that sail IOMs at our club, but we do sail a set course and keep an eye on each other to make sure no markers are missed, and it is the only way that I know if either I or my boat is improving.

Having built the Boxkite, a twenty year old design and the Nimbus, almost as old, I wanted something more up to date, and the Elipsis fits that criteria and is a woody, as building gives me a lot of pleasure and satisfaction.

What are you going to use to plank yours with? I was thinking either hard Balsa or Obechi.

Regards.

Eddie.

[Tim RoweParticipant @timrowe83142]

Eddie

I haven't got the drawing yet so I am not sure. It is possible that I might double plank it first with balsa and then an external veneer of mahogany. I have various stocks of well seasoned wood that I can machine to the sizes I need.

I am quite sure balsa will figure prominently and I will be generous with the original thickness to give me a good sanding allowance to fair things up.

I would like to get into soldering and home anodising aluminium then I could make many of the fittings. I already have pre-bent mast sections from SailsEtc and I shall use their booms and boom fittings. It's a pity the Graupner Regatta sail winch does not seem to be available any more. I had one on my Topiko and it failed. Shame because it was strong and quite fast and not so expensive as the RMG. It also had an additional lead to bypass the supply via the Rx.

Tim R

[geconParticipant @gecon]

Hi Tim, ref sailwinches:

I have Graupner 5217 sail winches in the Fisher. If you look at http://www.krickshop.de under 'elektroniks' you will find their winch servo, the 79074. I have one of these in the Comtesse yacht and I have bought some for the Colin Archer projects.

I beleive they are very similar (if not identical) spec to the regatta winches and cheaper at about 70 euros. I don't know how fast a winch you need but I think the krick Windforce series come in two speeds. The Krick winches come with enclosed drums which I think is better than the Graupner open drum.

Having said that, The first 2 graupner 5217's I bought (in 2019) also had enclosed drums but I think they were old stock. The regatta winches were listed as anologue and the Krick are digital.

CMB sell Krick winches…..as do 'Krick'!

George

[Tim RoweParticipant @timrowe83142]

Thanks George

Very helpful.

Tim R

[Eddie LancasterParticipant @eddielancaster]

Thanks George I will check them out.

Tim the drawings allow 3mm on the shadows for planking.

Eddie.

[Author]

Posts