Updates to Plans |
|
|
We spent the 2006 season sailing our Merlin Tucanu. This was the first time I had cruised an open deck catamaran for 15 years (but I did cruise and race a Wizard in the mid 1990's) As a result I have a few ideas that will improve both comfort and performance. The sketches are given to give you an idea. I am not offering these changes as detailed plans, but those of you who have already built your own boat should be able to make something similar without any problems. They are drawn for Merlin, but should also work, with modifications, on Janus and Strider. 1) I like telescopic tiller extensions, one on each side. However they are very expensive. So I got telescopic boathooks, removed the ends and fitted a universal joint. Total cost was 1/4 the real thing. After a seasons heavy use they are still working well. 2) To reduce forestay sag and mast loads the new Tucanu rig has a bowsprit and a forestay that is 500mm aft of the original position. Thus the genoa is smaller (and so easier to handle) while we are fitting a new larger racing mainsail, see below 3) Many people now use a "squaretop mainsail" for racing. This is very similar in concept to the mainsail I made for Cockleshell Hero back in 1980! We ordered a triradial carbon sail from GM Sails in Australia. CLICK HERE to see the new rig. But please note that the Strait of Georgia, where we race, is an area with predominately light winds and flat seas. Unless you are very experienced this rig may be too powerful for English Channel sailing, for example. 4) The Shadow/Strider Club had a deep mastbeam which we found a big improvement over the standard beam. The new Tucanu beam is shown HERE. It also has the advantage that the mast foot and hence boom is higher (note you will need longer rigging). If you do not use this deep beam and have a wide beam version of a micromultihull then I recommend fitting a dolphin striker under the mast beam to limit deflection. 5) The micromultihull daggerboards were originally drawn to make the best use of plywood sheets. However for optimum performance you can extend the length of the boards between 250 and 300mm. 6) Maybe we are too old for small boat cruising, but we like more undercover space. So we are making a small cuddy. This will be removable when racing and will fit in our truck for transport. It can have a fixed nacelle or a "pop bottom" as used on Wizard and Sango. The bottom needs to be 9mm ply, but the rest can be as light as you dare. You may also need to recut the genoa to fit. The photo shows the almost complete cuddy being fitted to Tucanu's deck
To see the general cuddy details CLICK HERE To see the cuddy dimensions CLICK HERE To see the pop bottom details CLICK HERE These drawings make the cuddy look large, so CLICK HERE to see the cuddy with rig above - much better visually! You will notice that the boom is angled up to give yet more room as we found ducking under the boom hard on our backs and knees. This change was easy to make, as we simply cut the sail along the first seam. Just to repeat, these sketches are to give you ideas. At this stage I am not going to draw detailed plans. Download Plans Although we spent a great deal of time and effort in making our plans available in electronic format unfortunately a few errors crept in. So please use this page to update and correct the download drawings. Some of the errors we have noticed ourselves, but please let us know of any more so that we can update this page and make the download drawings as accurate as possible. Thank you Study Plans As you will see elsewhere, the study plans come with a link to webpages that include the Materials List, photographs, owners reports etc. If you find that clicking on the link doesn't get you the pages you want then I suggest you copy and paste the link into your browser. ================================== General Notes: The normal method of marking out plywood bulkheads using full size patterns is to lay the pattern on the plywood. Then "prick though" the pattern with a nail or bradawl at say 1in or 30mm spacing. Remove pattern and "join the dots" ==================================== Pixie Materials list Deck jig Bulkheads Bhd2 Deck Jig Reading from the left of the drawing the measurements are: 5, 140(horizontal dimension), 30, 100, 150, 183, 195, ALL 500 (horizontal dimension), 195, 180, 145, 90, 140 (horizontal dimension), 70 The cutout in the jig doesn't have to be too accurate as the ply will form a fair shape. Rudders The rudder drawing reads: Steering is more positive if "Ackerman Linkage" is used (as on the front wheels of cars). This can be done by making cranking tillers (angle in 10deg) as shown dotted below ============================== Quattro 16 Notes for Quattro Full Size Patterns It is important that the patterns are printed out at the correct size!! Print out on A1 paper Sheet 1 Bulkhead Patterns Total Vertical Distance BHD4 must be 565mm OR if you cannot easily print out the full size patterns you can use the following offsets. Draw a fair line through all points. NOTE: You will soon discover that the "stitch and glue" method used is not particularly accurate as the plywood forms its own fair curves. Thus the bulkheads may not fit exactly. Use the full size pattern drawing for other bulkhead details BHD 1 Height gunwale to keel 492 BHD 11/2 (note this is a half height bulkhead) Height gunwale to keel 282 BHD 2 Height gunwale to keel 532 BHD 3 Height gunwale to keel 516 BHD 4 Height gunwale to keel 498 BHD 5 Height gunwale to keel 400 Transom Height gunwale to keel 295 Sheet 2 Hull Centrelines on Cross Section Setup for Fitting Keels Horizontal Distance must be 195 mm when printed out CLICK HERE for a dimensioned sketch of the Quattro 16 keels ============================== Janus Unfortunately there was a problem when these with these drawings were scanned. They are being re done. As a temporary fix I will send paper sheets, as required, to those who need them (Note: Not to partial plan customers, but only to those with full plans) Sheet 2 Setup Note 9) Fit side stringers, beginning at the keel and working down. Fit port and starboard stringers at the same time. Check that hull is not twisting as stringers are fitted. Glue and screw as 8) above. Note: if stringers are not long enough they should be scarphed together before fitting, see sketch at 2B1. Stem see VIII, IX, X Sheet 3 General Procedure Deck Framing ============================== Sango Offset table Although the full size patterns are correct I still include an offset table for use as a check. I recently discovered a couple of errors in the table: Frame 3 WL2 should be 215 Daggerboard Position The drawings show the daggerboard cases fitted on the outside of the hull. That is so that they do not interfere with the wing lockers. However the photo sheets show the daggerboard case on the inside of the hull. The builder whose boat I photographed chose this position to make it easier to reach and adjust the boards. There is no real difference in performance between the two positions so the choice is yours. Sango and Wizard Basic Hard Chine Materials List Hull planking 12 sheets 6mm ply 3 sheets 9mm ply Wizard needs 3 fewer sheets 6mm ply ================================== Skua Tillers should be 700, not 480 long ============================== Gypsy Daggerboard The total length of the board is 3050mm and the part below the waterline is 1350mm |
|