Page 3 of 34 FirstFirst 1234567813 ... LastLast
Results 31 to 45 of 502
  1. #31
    Join Date
    Aug 2002
    Location
    Sydney, NSW, Australia
    Posts
    5,014

    Default

    Thanks for the update Midge. I've been hanging out all weekend wondering where you were up to.

    Sorry, probably I wasn't paying enough attention earlier, what's a foil?

  2. # ADS
    Google Adsense Advertisement
    Join Date
    Always
    Location
    Advertising world
    Posts
    Many





     
  3. #32
    Join Date
    Nov 2003
    Location
    Australia and France
    Posts
    8,175

    Default

    Quote Originally Posted by craigb
    Sorry, probably I wasn't paying enough attention earlier, what's a foil?
    No, my apologies... I've been trying to keep away from jargon, or at least explain it when I use it:

    I s'pose silentC will look all this up in Wikipedia and fix my mistakes anyway!

    "Foil" is not, in this case the stuff used in making beanies, but is a contraction for "Airfoil" or "Aerofoil" depending on where you went to school.

    Basically the rudder and centreboard of a boat are there to stop the boat sliding sideways in the water, by resisting the "push" of the sail if you like.

    Now if you think about how an aircraft derives lift from it's wings, as it goes forward, it also goes upwards. Applying that to a boat, if, instead of using a slab of stuff just to stop it sliding, one can apply a foil shape to generate "lift" through the water, the boat will sail closer to the wind and not slip as far sideways (make less leeway in nautical terms).

    It gets a bit interesting from here: An aircraft can change the shape of it's wings to generate more lift as it's speed slows, but it's a bit hard to do that underwater. A few years ago (before NASA) it's predecessor an organisation named with the rather helpful acronym NACA, did a whole heap of research on how foils work, and what shapes worked when and how, and created hypothetical shapes in wind tunnels over a wide range of speeds. These were subsequently published in grand volumes and became the basis of many yacht designers keel shapes for decades.

    Now, with the advent of computers, designers and engineers have been creating new "improved" varieties.

    So why go to that trouble in a Puddleduck??

    Because it's fun for us to build secondly, and firstly that in identical boats, a good centreboard and rudder can gain many minutes round a race course.

    Even an ungainly tub which may well be the slowest boat on earth (not the PDRacer of course ) will gain significantly in overall performance.

    The snag is, that a "good foil" has to be accurate to about half the thickness of the finest shaving from my BU Jointer, hence the flatboard sanding to finish off, and the time taken to get the profile right.

    These boards aren't quite up to World Championship standard , but they'll survive running aground, and are a compromise that's easily within the skill level of an average handyman. The last really nice set I built was few years ago, out of Western Red Cedar, using my old faithful #4 with a Surform thing for the finer bits, and lots of sanding.

    Hope that's not too much info!

    Cheers,

    P

  4. #33
    Join Date
    Aug 2002
    Location
    Sydney, NSW, Australia
    Posts
    5,014

    Default

    Thanks mate. (I think, as I wander away with a furrowed brow)

  5. #34
    Join Date
    Jul 2005
    Location
    'Delaide, Australia
    Age
    65
    Posts
    8,138

    Default

    Hi All,

    If you look carefully at the picture of me (in the red T shirt) in the most recent post with photos I am holding the foils (centreboard and rudder). As you can see that they are laminated out of lots of pieces of finger jointed crapiata.

    There is a lot of load on foils, particularly the centreboard which will undergo a force when sailing similar to the weight of the crew. Similar to having the boat lying on its side with the crew sitting on the centreboard about half way down.

    It is normally good practice to glue it up out of full length strips of timber, but to keep with the CHEAP theme of the boat and to make use of the salvage timber that Midge keeps under his house we have decided to run the risk.

    We THINK it will be strong enough and we have taken pains to make sure that the short bits of wood are down near the tip of the blades, well away from the maximum load which is just where the blade exits the hull. You can see this in the photo.

    A lot of the strength is in the fibreglass that will be laminated over the top, but some care needs to be taken with the timber.

    I did a bit more today (pics will be posted tomorrow) but ran out of the high strength powder that is added to the epoxy for gluing. If it arrives early tomorrow as promised I plan to get the sidedecks - internal stiffening and centreboard case fitted - finishing the cockpit area.

    Big steps (with any luck at all)

    Good night and good luck
    Michael Storer

  6. #35
    Join Date
    Nov 2003
    Location
    Australia and France
    Posts
    8,175

    Default

    Today was a work day.

    So now juggling Eureka time, I'm trying to get it finally ready to coat (and float!), but Michael is beavering away in the background, albeit we only put in an hour or two each this evening.

    Basically all the bits for the Puddleduck hulls are now made, and the side decks, centreboard cases and tank sides will probably be glued in sometime tomorrow.

    Tomorrow night I'll do a bit more on the rudder pintles, which we are making to save $30 per boat, and finish off the other pair of foils, which I rough shaped tonight.

    Pics:
    1) No, we are not under lazer attack! The red lines are actually sunshine through voids in the core of the el-cheapo ply. Michael has done a few quick calculations and reckons we'll be right (well he actually said it's too late to do anything, we'll have to see how it goes!) ... but we did plan to have two cross beams pretty much in line with the voids (apparently! )

    2) Side bouyancy tank front panels now glued in place (held by temporary screws through the hull), deck coaming in place and nice curvy deck showing it's stuff.

    Note the angle of the bulkhead and the cleat on the transom, both of which will support the tank face at the same angle to the hull bottom. This should give quite a "boaty" feel when it's all done.

    I can't remember if I've mentioned this above, but the deck curve is the offcut from the hull side panel cutout, and idea borrowed from Ken Abrahams who built boat #2, although we have changed the bouyancy tanks somewhat!

    Cheers,

    P
    http://www.pdracer.info
    Last edited by Boatmik; 12th December 2007 at 08:33 PM.

  7. #36
    Join Date
    Nov 2003
    Location
    Australia and France
    Posts
    8,175

    Default

    Before we do a bit more tonight, I thought I'd update the process!

    The side tank panels have been cut and partially fitted, we have about 2 square feet of ply scraps left to build the centrecase gussets and that's it! We cut the side tanks a bit fine in the height department, which is why the fit is a bit rough, but epoxy fixes all.

    When Michael publishes his version of the plans he'll drop the hull height by an inch, and all this fiddling will go away!

    Pics:

    1) Centreboard cases now with beams attached top and bottom. Note only one needed per boat!

    2) Side tank side clipped into place, but about an inch higher than it needs to be (it's the overlapping bit at the top of the deck held by the spring clamp) so that scribing the bottom can take place.

    3) Scribing the line of the bottom is easy with a small block of wood holding the pencil off the floor.

    4) Michael (Bless his heart!) using a plastic bag full of epoxy to "stitch" the bottom panels in. Once the epoxy has gone off, we'll take out the temporary fixings and do a proper structural fillet.

    Note the gap towards the rear of this one where we simply ran out of ply! It will be covered by a fillet in an hour or two and no-one will ever know!

    More follow

  8. #37
    Join Date
    Nov 2003
    Location
    Australia and France
    Posts
    8,175

    Default

    So with the tanks in place and the side decks fixed temporarily, the dear things are looking like a pair of boats (or tea chests depending on your point of view).

    We have a longer front bouyancy chamber than appears common, and our masts will mount through the deck. This will compromise the watertight nature of the tank a little, but we have plenty in reserve, and will devise a simple gasket arrangement.

    The curves of the sheer, side deck, and angled rear tanks work wonders in tricking ones eye into thinking this is a boat. It's almost cute...

    The two beams on the floor in the first shot haven't yet been fixed in, but will fit either end of the centreboard case. We'll then glue a couple of stringers (skids) lengthwise under the hull, so the structure becomes a grid with plywood holding it together. Every bit of structure then ties together to form a light, but quite rigid shell.

    Note the Eureka in the background of one of the shots has rolled over to expose it's belly. Must be expecting some sort of a tickle later in the night... the sort that happens with 120 grit on a ROS.

    Cheers,

    P

  9. #38
    Join Date
    Oct 2001
    Location
    Warwick, QLD
    Age
    45
    Posts
    3,462

    Default

    Can't wait for the finish Midge, the ducks are looking great. I think I will build the canoe first, it looks easier than this . You and Michael will have the best designed and most aesthetically pleasing boats in the PD fleet!
    Have a nice day - Cheers

  10. #39
    Join Date
    Jul 2005
    Location
    'Delaide, Australia
    Age
    65
    Posts
    8,138

    Default

    Quote Originally Posted by Wood Butcher
    Can't wait for the finish Midge, the ducks are looking great. I think I will build the canoe first, it looks easier than this . You and Michael will have the best designed and most aesthetically pleasing boats in the PD fleet!
    Howdy,

    I think as Midge has mentioned we keep being slowed up by designing on the fly. The natty appearance of the boats reflects a big slab of time discussing and nutting things out either on the computer or paper.

    The assembly procedure can also be streamlined considerably - for example the side tank fronts and transverse bottom frame could be made on the bench and just dropped into the boat. As could the centrecase assembly. We have been held up because we have had to work out exactly how the bits relate and the best way structurally and aesthetically.

    Also we have made some mistakes along the way which can be avoided by anyone who follows us later - we'll be making all the info available.

    The biggest of these was not allowing quite enough ply for the faces of the aft tanks - you can see the gaps we are going to bridge with epoxy. Not a problem, but it does take time. With the final version we will be dropping the depth of the boat's sides by 12mm which will give us plenty of ply for the tanks (at least a 4mm offcut ).

    We could have avoided all the pain by just having the inside faces of the tanks vertical, but felt that angled tanks had two effects. They make the boats prettier and they do give quite a bit extra buoyancy volume.

    When you have our final information it will be a matter of simply cutting it out, putting the components together on the bench then assembling the boats - We hope to avoid all the "fit and try" work as far as possible.

    Best Regards
    Michael Storer
    Last edited by Boatmik; 12th December 2007 at 08:34 PM.

  11. #40
    Join Date
    Aug 2002
    Location
    Sydney, NSW, Australia
    Posts
    5,014

    Default

    So are you going sailing this weekend fellas?

    You don't have masts or sails yet do you?

  12. #41
    Join Date
    Nov 2003
    Location
    Australia and France
    Posts
    8,175

    Default

    Quote Originally Posted by craigb
    So are you going sailing this weekend fellas?
    Yes. but Michael is also putting pressure on me:eek: to go for a paddle in the Eureka on Saturday as well!
    You don't have masts or sails yet do you?
    This morning before work I selected 26 pieces of the finest 12mm crapiata (formerly wall lining), which tonight will be scarfed into 8 x 5.4m lengths.

    Tomorrow night, we'll taper and glue them (the masts will be simple square box sections)

    Sails may be a bit of a last minute thing.....

    We don't have a lot of assembly to do, but it's a bit fiddly, and I haven't finished making the rudder pintles yet either (better do that tonight as well...)

    They always look rough and ready at this stage, it's amazing what a bit of sanding and some varnish can do! I expect that painting and final finishing will soak up the weekend after Michael goes home! (Then he's got to finish drawing the plans so he can get them on his website for download).

    In the meantime I'm wading round in a sea of sawdust, wondering why I never finished the DC ducting!

    Cheers,

    P

  13. #42
    Join Date
    Nov 2003
    Location
    Australia and France
    Posts
    8,175

    Default

    I think I actually spend more time posting on this thread than actually working on the boat... (Thanks Michael!)

    Today, I went to work.... again.... but I came home for most of the afternoon to spend a delightful hour or so with AlexS who was just passing by. Mrs Midge thought he should help Mik, 'cos it wasn't fair having TWO of us standing round watching........

    Anyway, on to the pics:

    1) Remember the big gaps under the side tanks? Today was the day they disappeared under a glob of bog. Mik made a super-sized filleting paddle to get the right size in one go.

    2) Here's the inside of the tank nicely sealed. Check the pics above if you need reminding; yesterday the tanks were tacked in, today the temporary screws removed, and the finished fillets which become the bottom structure installed.

    3) The outside of the tanks complete, and waiting now for the epoxy to cure. While things look a bit complicated at this stage, they aren't at all, however many jobs can only be done in sequence and that leaves a few hours till the glue becomes sufficiently cured to start the next one. These sorts of things are ideal for a midweek evening, where you can do a bit, then go and watch Teev.

    4) In the meantime, I've started on the masts so I thought I'd do a gratuitous scarfing shot or two. There have been a number of threads in the past which mention "SCARFING" as though it is a great mystery, it's not, so I thought I'd throw in a couple of options.

    This shot shows four layers of timber cut at once at an arbitary angle. (actually Mik made me do them again to get the correct 1:6 particularly because our masts may be a bit ummmm.... lets just say we don't have really good material ) This is easy to do, and if you are a bit better than I you may even get away with just joining them "off the saw".

    5) Most of us, will need to plane them a bit, so keep the same stack, clamp it down, and give it a light plane till the ends of the timbers are parallel to each other and at 90° to the sides.

    That's all there is to it, flip them over, glue them and clamp or nail, or even drill a small hole and fix the joint with a bamboo skewer.

    Of course none of the above is how I did it, so you'll now have to go to my next post to find out the easy way.....

    Cheers,

    P

  14. #43
    Join Date
    Nov 2003
    Location
    Australia and France
    Posts
    8,175

    Default

    Pic 1) My quick and really dirty scarfing jig for the bandsaw.

    A few things to watch here: it's a recipe for losing fingers or half a hand, so use a clamp to hold the timber in place, and although it's not visible in this shot, I clamp a stop in place to prevent the sled going past the distance needed to cut the scarf.

    This makes it almost impossible to cut yourself, even if you do have a bit of brain fade. The jig is as it looks, a bit of scrap for base, runner and fence, four screws and a bit of glue, and it cuts perfect scarfs.

    2) The mast bits layed out, I'm trying to get rid of the really crook bits, and deciding which bits we'll have to sleeve. Grade A knot free timber this is not, but it was free, so we'll give it a go.

    3) Detail of the quality of the timber, so you know we're not cheating here!

    4) The first four sides scarfed and glued together, all tacked to a base to keep them straight while the epoxy sets. Tomorrow morning I'll do the other four sides. Basically the mast will start off 55 mm square, and taper towards the top.

    Michael came in and remarked that it looks a bit tall because the pieces are so slender. I corrected him. It actually looks tall because of it's 5.4m on a 2.4m boat :eek: :eek: :eek: . It's OK we'll build a smaller rig for the kiddies (and us on days when we don't have to prove how manly we are!)

    Cheers,

    P

  15. #44
    Join Date
    Nov 2003
    Location
    Australia and France
    Posts
    8,175

    Default

    Hmmm.... Sunday is looking very close indeed. Too close for comfort!

    We've just spent the whole night with some friends on their 48 footer, so the best laid plans fell well astray.

    Michael has the centrecase gussets together now, and the whole assembly glued ready to drop in to both boats tomorrow, and he will probably glue on the side decks as well.

    I've started on the rudder hardware, made some timber gudgeons, drilled and filled with epoxy to form a bearing surface, (after drilling out in the morning), and bent a bit of 1/4" SS rod to form the pin. Interesting cost excercise there: Boat shop cost for the rudder fittings $30.00 for the gudgeons, $20.00 for the SS pin.(Per boat) Our cost: Gudgeons from hardwood offcuts with epoxy bearings, a bit of 1/8" aluminium angle from a rubbish pile, and 1m of SS rod from a handrail place $4.00 (enough to make three)

    A total saving of $96.00 for two boats! :eek:

    I was hoping to get the masts and sprits glued up tonight, but only got as far as milling the pergola beam that will become the sprit timbers!

    We fear we may just have lost on night too many, to make Sunday, but we'll plod on!

    Cheers.

    P (Darn! this is my 5000th post, and I tried so hard to cut back to 1000 per year! )

  16. #45
    Join Date
    Nov 2003
    Location
    Australia and France
    Posts
    8,175

    Default

    We are at that point of the job where we are making progress but can't see it, which makes it darned hard to record! :eek:

    Then when we do, it's amazing what's been done in an hour or two.
    Pics:

    1) My metalworking friends have often remarked that timber is too unforgiving, if you make a mistake you can't just weld a bit back on.

    Well you can. Here the sprits are being scarfed, because the beam I cut them from was a few feet short one end. Note the generous (but oh so tidy) glue squeeze out from the clamped joint. I'd have to be confident with that one. Glue on one of the other scarfs, the other waiting to be coated.

    That's all there is to it!

    2) Another trick which has been brought up more than once on this forum. Here we've got a bit of glue on a screw, which has "detemporaryized" it.

    To remove an epoxied, glued, or even rusty screw, bung a soldering iron on the head of it for a few minutes, and let the heat do it's trick. They pop out as if you'd put soap on 'em.

    3) While I was fiddling with other stuff (like uploading photos) michael was busy fabricating the centreboard case structure, and carefully attaching the floor beams at 90°. If you get this angle wrong, the centrecase will be installed at whatever angle you accidentally decide!

    4) Here the case has been glued in, and the side decks are on permanently as well (hence the clamps). Don't worry about the mess, it all needs a good clean and sand after the glue has cured, and the screws have been removed and filled.

    Yes the ply gusset is in two pieces, we are cutting our ply quota very fine indeed!

    Note also the tape, chisel and other tools blue tacked to the side of the hull for convenience!

    We are really on a roll now... just wish it was a long weekend!

    Continued.....

Page 3 of 34 FirstFirst 1234567813 ... LastLast

Similar Threads

  1. Another PD Racer for Perth
    By BANDIT in forum Michael Storer Wooden Boat Plans
    Replies: 6
    Last Post: 12th April 2010, 10:51 PM
  2. PD racer, outboard & row
    By soundman in forum Michael Storer Wooden Boat Plans
    Replies: 1
    Last Post: 29th March 2008, 12:02 AM
  3. What is this old racer - help please
    By TassieKiwi in forum MISC BOAT RELATED STUFF
    Replies: 10
    Last Post: 24th April 2007, 02:01 PM
  4. Building a PD Racer
    By Daddles in forum BOAT BUILDING / REPAIRING
    Replies: 1
    Last Post: 15th February 2007, 04:45 PM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •