UK-Cherub Forum
Cherub Chat => Tech Chat => Topic started by: daryl_wilkinson on October 21, 2008, 03:58:18 PM
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I HAVE CHANGED THESE FIT-OUT LISTS SEE BELOW:
As the main site is not accepting uploads at the moment I thought I would start this thread to provide a resource point for Banshee owners ( and anyone else for that matter).
Post helpful images or design files here that could be useful.
Below are a few pdf files that will give a guide to fittings lists, rigging systems and sail dimensions. They are not definitive but should put people in the right ball park. But they are what I am using.*
* may be subject to change.
Hope some of this helps.
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Plans*, Mast and Sail plan measurements.
*some of these measurements have been slightly altered on my boat.
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Proposed 'T' foil adjustment system. I'm still thinking about this one...
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The diagnosis from the T-foil that erupted on the back of Slippy at Corus was as follows below. We were traveling very nicely at mach3 with both helm, crew and most of the boat's weight sitting on the foil.
Failure 1 - Pin bent above top gudgeon (tiller is not broken so this must have gone first in the direction of the blade)
Failure 2 - Foil went to very negative - bottom gudgeon went pop
Failure 3 - Foil became sea anchor - then separated from blade
Design pointer - The fore aft forces at the top of the rudder are lower than at the bottom. With a lowish drag asymmetric section, at speed, the drag was large enough to bend the pin - there was almost inch between the tilt controls and the top of the gudgeon. Therefore I would strongly recommend that any fore-aft control is either grounded on the transom/gantry (i.e not loading the pin) or pushed flush with the top of the top gudgeon.
Comments on drawing.
The mechanism drawn moves the rudder by shortening the distance between the end of the end of the tiller and the top of the rudder pin.
Some of the mechanical advantage from blocks on the tiller is wasted by having to overcome the loading on the tiller in the opposite direction from the control line i.e. the pulley below the arrow for "Custom Plate" is attached to the tiller, attaching this block to the gantry would remove this loss.
Mounting the "custom plate" and pulleys under the tiller would remove the bending problem on the pin as described above.
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I see what you are saying about putting the 'custom plate' underneath the tiller arm, good point, thanx. And also the return blocks. But they are right devils to keep on the rudder pin center line if I put them on the gantry. I'll have to keep thinking about this one.
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Those are excellent drawings, and help to clearly illustrate how to rig a boat, I will get them onto the main site soon.
For the T-foil, I think you are making life difficult for yourself. You have the pintle adjustment on the stock which gives you the changes in helm feel as you rake the rudder and by routing the purchase from the stock to the boat you have added complexity.
Just put the pintle adjustment on the back of the boat with the rope lead and blocks on the boat, there is no change in helm feel and the setup is very simple just a 6:1 or 8:1 required.
(http://www.sailingsource.com/cherub/test/lib/exe/fetch.php/tech/2681-20071220a.jpg?cache=cache&w=800&h=600)
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Thanks Phil, and you are right about the 'T' foil adjustment system. Unfortunately I am working backwards out of a hole on this one as I had specified a rocking pintel design and was convinced to go with a worm drive and built my stock accordingly, which means I haven't got any tolerance to fit what you are suggesting.
I think I am going to go back to a worm drive but possibly disconnect it from the tiller extensions and use a rope system to adjust it. That way it should be faster to use. Like a mighty screw system. What do you think?
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We mounted a cleat on the tiller, next to the pin and adjusted it form there. The string from the single cleat then Y-ed out to each wing. Worked a treat with a 4:1 advantage and was easy to adjust in the on-off sense. The next foil will have the same mechanism with an additional twisty grip for fine movements (or putting a mite more foil on down wind).
If asked nicely Strawberry might post some pictures of it ?
I had a similar constraint, the crew and owner demanded that any T-foil additions had to be entirely fitted without altering the boat - so the normal rudder could go straight back on.
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Please, Please Stu post some pic's. xxxx
Is that nice enough? ;D
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If you can't modify the boat, then you are stuck with rotating the stock
I think if you are going to use a worm drive then you are best using it with the twist grip tillers, putting rope onto that system would be tricky.
if you 100% want the rope adjustment then I would use a tube for the custom plate, with a hole at the bottom and small slot at the top, it will locate better.
Then dead end the string on the tiller, a single block on the "custom plate" fwd to block on the tiller. The line is then split into a loop, one side of the loop down each side of the tiller to one block each side at the top of the stock, then down to one block each side at the bottom of the stock close to the pintle. You then put a floating block into the loop which is attached to the rest of your purchase.
The loop and floating block mean that there is no change in the length of the line as you turn the rudder.
Born Slippy's description sounds good too
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I have a more extreme version of Rolands system on Badgers at the moment. Only boat modifications required were a few turning blocks and cleats as all the actual moving bits are in the stock, which is the same as the twist grip stock (the gear box fell out and sank at Bala!) I will try and get some photos of mine as it seems to work quite well. I need to refine the bungy return system as at the moment it is just a shock cord still with the hooks attached!
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Here you go Jack... Seeing as you asked so nicely.
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Just put the pintle adjustment on the back of the boat with the rope lead and blocks on the boat, there is no change in helm feel and the setup is very simple just a 6:1 or 8:1 required.
(http://www.sailingsource.com/cherub/test/lib/exe/fetch.php/tech/2681-20071220a.jpg?cache=cache&w=800&h=600)
I think it is the only piece of aqua that Gilles was able to recover after the disaster. :'(
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Being a slow coach does have it benefits! 15% Vat and 20% off from 'www.sailboats.co.uk' on fittings! Thats the best deal I could find. Worth a look if you are in the market. Here's my lists...
BTW the prices on these aren't with the different VAT or discount.
And I ended up at sailboats because P&B were so useless.
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No wonder you've been a slow coach Daryl, you've been spending your days pissing about drawing diagrams rather than boat building!! :o
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kind of.... although P&B were such a bunch of Charlie's I wasted a couple of months just with them. Add to that some scum bag robbers nicking my trolley which took forever to make anyway and I've had plenty of time to draw me pictures!! I also need to plan stuff out and ponder it and I thought it would be useful for everyone too. Plus doing it slowly is also good for my cash flow.
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I find those moments betwen checking in and boarding flights are quite good for thinking about bits of boat making lists of things needed and sketching diagrams for layups. Best thing is your thoughts don't get interupted. Thanks for posting your drawings I'm sure they will be useful to me at some point.
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Just in case anyone thought that I really wasn't building a boat! Here she is. Edging that little bit closer to the water. And the best thing? When I got her home from painting my boy said with big wide eyes " that's mental, it's going to be crazy, I can't wait! " :-)
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Nice work Daryl, that certainly is looking very shiny, seems like you have an astute son too, wisdom beyond his years !
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Thanks Graham. And a belated congratulations on your Open Meeting Win. Your lad must be made up!
PS I love the boat name!
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Nice work. Are those B14 style removeable racks?
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Yes, and thanks, they are indeed B14 style removable racks. I have another narrow set for Cherubing. And there will be floats for a Trimaran, maybe next year.
I decided to design the boat with a removable rack system so I could get as much use out of the boat as possible, with all sorts of crews and sailing locations in mind.
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Holy crap Batman.... I got a set of sails today, I only ordered them in October!
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Wowee !! Pleanty of time to make them fit for the nationals then !
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Not so fast... I've got to get the boat back from Mr Cooke first. And then convince me lad he's not going to die sailing it! I keep showing him pictures of Eddie, and he's warming to the idea. Then I add... we'll put the small sails on first, and the hiking racks, it'll be just like the Mirror. ;D I'm not sure I've convinced him! ;D
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updates....
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Sorry Daryl, but that just isn't legal ;D. You're going to have to sart ALL OVER AGAIN and give it to me.
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This boat is so versatile!
it even has a number plate and indicators so you can sail to events as well as at them.
beating up the M4 could be tricky though. ;D
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boat
I thought it was a garden ornament ;D
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More of a streamlined caravan, the amount of times it has been down the M4 and M5. :'(
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Got my Banshee wet today.... quite a few little things to sort.... mostly bits of elastic to stop rope getting tangled and easier rigging stuff. Quite happy though. Must say it was all a bit freaky getting back in one of these things after 5 years off.
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those hiking racks are freakily wide, i sense some light-weather, single-handed trapezing coming on if i had that. (been doin alot of that recently
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ummm.... they are wide and certainly freaky, it will take a while to get used to them.
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Looking good Daryl, will you be converting it into a cherub and taking it to the nationals, I know Dan is going so it would be great to have the 3 banshees together in one place, red white and blue, I smell a photo opportunity !
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Congratulations for getting her on the water. It would be great to see you at the nationals.
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Congratulations for getting afloat.
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Well done! Looks great!
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Thanks guys.... Nationals, maybe?
Me and Luke are off to Minorca Sailing next half term for some solid breeze and twin wire time. Burghfield S.C isn't the best to ween Luke into twin trapezing... or in fact me! ( it's been awhile!). We will be looking at the single wire option soon though. After I have sorted all the bit's that you don't realize you needed to sort until you go sailing and they instantly get wrapped around something you'd never have thought about! Oh and getting the board to go all the way into the slot!
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any other pics? get the spinny up?
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There was unanimity that Largo 2006 was a textbook nationals: Come along to Largo 2010 to make it bigger and better!
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been out again recently???
flown the spinnakert???
any pics???
sorry just interested
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Sorry no more outings yet. Weather, Work and Willingness have got in the way. In truth I have been doing the bimberling I needed to do before it went out the first time. Like sanding the board down so it fits! And cutting and splicing etc... ( I need to get my order in for some trap stuff ) I will report when we are out again. My old man is being carted around in real Ambulances at the moment so this may curtail things in the short term as well, depending on outcomes.
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Sorry to hear that, hope he's on the mend soon.