The opening sequence @3:00 to 4:00 where Steve is recapping is outstanding. The finished knees, decking beams and all the bronze fasteners create a image of wooden ship art that one can only appreciate after watching it being created as we (and u) have done. When you watch this video you all must feel a great pride of the work to this point.."It's a boat"... Glad you're taking time off to R&R.
To me, Alix's journey from video guy and helper to boatbuilder has been the most impressive. He's smart and methodical. His segments are often the most interesting parts of a video.
Very nice transition and shape on the mast Alix. At 3:00, the massive knees framing Stephen as he talked looked amazing. What a picture or poster that would make. Thank you all. Take care all.
I like the new intro sequence. I like the shaping of the mast below deck. I cannot help thinking about all the people that have handled that mast, from a tree to Victoria's mast, to the years of maintenance on Victoria, now shaped again for Arabella. A proud history for any piece of wood.
The load transferred to the below deck section of the mizzen mast is not only compression load as indicated in the video. The fibers of the wood will transmit a bending moment about the deck support which will serve as fulcrum for these loads. Forward displacement above deck will translate to rearward displacement below. As the base is fixed, the below deck section will want to bow between deck and base and eventually fail if the load becomes greater than the below deck mast's strength to resist this deformation. That resistance to failure is determined mainly by mast diameter. Hopefully the above deck mast will be sufficiently located by stays to limit this bending load to a magnitude that the thin below deck section can withstand under strong winds and high seas. Great project, been following you every step of the way. Your commitment is inspiring!
Sometimes i miss the (far)old intro music but nowadays i´m looking cheerfully foreward to the new tunes. Good job Ben! After all the shaping, sanding and painting etc. i´m cuorius about the test fitting of the mizzen mast.
Its going to be a strange transition for all of us when this channel goes from a boat building channel to a sea faring adventure channel. I hope you take us along for that ride when it happens. I've been with you since the keel pour.
Well, hopefully it’s not as dramatic as one day we’re slinging tools and the next minute floating... but I think you’re pointing out how, for most people who want to sail, boatbuilding doesn’t need to be (or maybe shouldn’t be) a part of their journey to the water. It’s so different from sailing! A vast majority of people would do well to just get straight to the adventuring part. Hope you’re here past the splash, we’re glad you’re watching.
@@AcornToArabella If I'm alive I'll be watching. wouldn't miss you guys and the christening of Arabella for the world. I feel invested in your endeavor seeing all you've done. 👍
Amazing quality of the wood on the mizzen ; the tight grain looks like the top of a Martin guitar . Great work Alex on a difficult shaping job you've really developed your woodworking skills to a high level .
Feeling a little punchy is so funny. I feel like that when I wake up in the morning. I love watching your videos, it makes me feel a little less punchy lol.
One of the most outstanding developments of the build is the impressive amount of confidence you both have gained. You have become real shipwrights and find solutions to your problems instead of becoming mired down in worry.
Today on A2A I learned that a tote is not just a tote! I heard the name Roy Underhill which is always a positive thing, and that woodworking is "Just Plane Fun!"
I guess even if the mast base thickness was an issue it could be reinforced once it’s in situ but it’s amazing… loved the little demo Steve did with the stick in the hole
Ya'll need to add a coarse thread to the wooden plugs to allow pressure relief as you pound the plug in. That is why you found holes in the mast after you trimmed the wood. If you add the epoxy to the hole prior to hammering the plug in, the coarse threaded plug will allow the epoxy to fill the hole completely while the excess is expelled around the thread.
Alix it's a pleasure to watch you work. The mizzen mast is really beautiful. The time you have spent was worth it. I love how Carolyn is so positive and has knowledge under her belt. She is a great part of the rotating helpers. I wonder how many will return in the future. As always another great video. I have watched it twice now. Too bad you can't like it more than once. We are thinking of going kayaking this weekend. It sure has been hot enough lately. Happy Friday!
I've made a set of reamers (from spade bits) that have the exact shape of various fence or garden stick sharpeners. That way, any bung i put in has exactly the same shape of the hole, and i take out the rot as well. Having a small selection of sizes (first the sharpeners, then the reamers) is a good thing because you only take out just enough, based on the existing hole.
Being retired military, the last 10 seconds made me laugh. You two are in unison walking back to the boathouse. Says a lot about working closely with someone on a project.
Much progress, a lot of hard work, great to see the boards becoming a boat. Alex as a woodworker I have found I have better control of a drawknife riding it on the bevel (using the bevel like rudder) and holding the drawknife at an angle pulling it down and sideways at the same time. Maybe worth a try with the Main Mast coming. Fir is a difficult wood to work with, but vertical grain fir should have exceptional strength. I’m already for next week’s episode. Cheers, Will
Alix your work just gets better and better and the work on the mast is superb, BUT, at 12.45 there seems to be a terrific difference in cross sectional area from the full diameter of the mast which will be at deck level and the jump in size of the much smaller octagonal section which will go down to the keel. As an engineer, I fear the jump in sections could cause a stress raising area caused by the possible bending of the mast with the deck mounting point acting as the fulcrum and the section below deck at keel level. I saw Steve's demonstration but still have my concerns, however, keep up the great work, cheers from Terry in the UK
Structural engineer here. I think it's important to point out that the mast part below deck will still experience some bending moment. Definitely way less than if it was just a flagpole (i.e. no mid point bracing). The overall message from the little bracing demo is correct, that bracing it at the deck helps. But even in the demo you can see the bottom portion bending a bit. The amount by which it does is related to the relative stiffness of the supports, which is what alix was alluding to when he said it's hard to hold it. The more flexible the top support is (alix holding in demo, or deck structure in real life), the more moment will be carried by bottom portion of the mast. Even assuming ideal (infinitely stiff supports) at the deck and bottom, you have a max moment tapering to zero over the length of the bottom portion. I'm not saying this is dangerous, I'm sure the mast is sized for this. Just wanted to point out that the explanation in the video was a little bit too optimistic. Great video as always, love the content!
It's also good to remember that the original design by Atkin has the mizzen stepped directly on the deck with no part descending to a keel step. But of course you are correct, since the beam (mast) continues below deck and will not be capable of carrying significant bending loads at the deck, it will necessarily carry bending loads between the deck and the keel, just as the main mast will. When stepped on the deck, the deck step carries fore-aft and thwartship loads parallel to the deck and vertical loads onto the deck, while the mast foot simply rotates about some axis perpendicular to the mast line as a result of bending due to sail loading. All of the loading and structural support analysis is quite interesting, especially when seaway inertial loads are also included.
Honestly i would have been tempted to add bronze rods at the corners which would stiffen it up and also help anchor the mast in place more as the mast will lift as well as twist and bend. Plus having easy access to unbolt to remove mast should repairs be required. Facinating watching the boat building. Never knew how many considerations needed to be made !
@@boooshes thanks for the reply! I forgot about the fact that original plans called for the mizzen stepped directly on the deck. How much further down would you say the mast goes now? Moments scale with the squared distance, so even adding a foot or two of extra mast might lead to a nontrivial increase in moment at the base. Coupled with the fact that the section is reduced down to 4x4 "(plus corner chamfers), and you now have two things working against you. It might warrant a quick re-examination! Just for my own interest, I'd like to do a "back of the envelope" structural analysis of the mast below deck under different support condition assumptions. Any ideas what sail area the plans call for, and a reasonable worst case wind pressure would be? Only doing a planar analysis, so will of course ignore the much more complex bidirectional bending + twisting load cases.
@@eddiebizi I believe the keel step for the mizzen is roughly 4 feet below deck. You can also estimate by looking at the length of the modified section that Alex produced in the video. The sail plan for the mizzen can be estimated from the drawing of Atkins' Ingrid 38 knowing that the waterline length is an even 30'. I would calculate a maximum wind load at 35 knots on the unreefed configuration with a lift coefficient of around 1.3. HOWEVER, the details of how they will configure the stays and shrouds needs to also be established (which is also represented in the drawings) may be difficult. Note that the main mast is also keel stepped, so will also be subject to similar loadings/reactions/deflection characteristics. Since Atkin was a very accomplished designer, the mast scantlings and step design would have been selected to meet or exceed acceptable design standards of the day, here for a blue water cruiser. Compared to the main, this mizzen should be relatively lightly loaded (albeit smaller scantlings). I found a brief modern paper on mast analysis that is worth a quick read issuu.com/nbaddour/docs/alexbergeron_undergradthesis
Oh, the opportunity to carve some icanthus leaves at the mizzen transition... that chance may be lost now, but hey, It's not my boat. Big beefy transition spots are always a good spot for decorative carvings. Someplace to put some artistic inspiration into your work. But alas, I guess those days are gone for the average workman/workwoman. That spot, the sampson post, the larger knees, could all be spots for some nice carvings without harming the structural integrity. The few ounces of wood left proud would make no real difference in the performance. The time it takes wouldn't add up to much, in the long run timeframe of the project. I'm not saying adorn the entire ship with intricate carvings everywhere, but a few, here and there, would add a nice old world touch of craftsmanship to this clearly handcrafted vessel. But, again, that is my taste. And also, though it would add to the resale value to the upper end client, this is not my boat, and it is not being built with resale in mind. I just wish they were keeping the planking watered, those older planks sure are opening up some pretty impressive gaps. I know they will eventually take up again, but you have to keep it from sinking until it does take up. Oils and paint will slow how quickly the boards soak up the water, and soaking them first will affect finish adhesion. Keeping them swollen and letting the surface dry before paint/varnish helps to hold the inner moisture in and slow the drying out. I just hope it hasn't dryed too much at this point. Those seams are going to take a lot of cotton and oakum, but they should still be sealable. My hope is that they find an experienced caulker/corker or two to come show them the whys and hows of doing it the right way for the seams they have. They have put in a lot of work and resources. I want to see it float and sail, when it and they are ready.
Wonderful update, do hope Alix doesn't rough up his hands too much with the sanding though! If the work hasn't finished yet and you haven't found another solution since, might be worth making a few handles out of scrap wood that you can clamp the sandpaper to with another block of wood and some spare bolts.
i love to see you guys work on the Boat .. i am a craftsmen by my self (german Metalworker and love wood aswell) but i dont like the convex transition of the Mast 😁, having a invert corner like that is always a concetration of forces to that point, building it concave evens out the forces over way more area. i mean you can test it by making to "Sticks" with transitions like that convex and one concave and see what brakes easier and where it brakes. Just my two cents, keep up with the good work .. eager to see the next Video ^^ have a great Day.
I don't know if that applies to anisotrop (directional) materials. Where there would be a crack forming into the metal crossection, wood probably just starts to delaminate, . It is certainly not adding to the strength, but probably not reducing it, like it would in other materials. Just my two cents though, unfortunately I don't get to work with wood that often.
@@kilianortmann9979 it dosnt matter wich Material it is, it has something to do with the Flow of forces. so that you can imagine it and to say it easy: Forces behave almost like an liquid inside materials, if the wind pushes sideways on the Mast, the Force aplied spread out inside to the top and the bottom. Now we come to the Transition, imagine two funnel, one is convex and one concave, pour water in them. for the concave the Water will flow easy along the edge, but in the case of the convex, the water is diverted to the middle and meets there before it can continue downwards, which causes a back-up. so for a convax transition with a "sharp" edge at the smaller part like that, you will always have work more force at that spot, even more then at the thicker part, no matter if its metal, wood, carbonfiber or stone. The only difference in the material is how much the material absorbs itself beforehand. In Germany we have 3.5 years of education for many professions, especially construction. And physics, the effect of forces is part of every job that is involved in construction. So nothn i just made up, something i learn in School .. but still a very simplified explaining.
@@georghofmann1782 I know, I had those years and then some on top. The local forces will be identical for isotropic and anisotropic materials (assuming equal modulus of elasticity). An isotropic material will fail, where the stress is highest, at the bottom of the notch. Anisotropic materials will fail, where the local resilience is exceeded, that could also be at a point with lower stress, but also lower local resilience. core.ac.uk/download/pdf/153229794.pdf, page 56 and 74 say that there is a moderate influence, but the specific shape of the notch is almost irrelevant. It's still a factor (that's physics), it is just not as big of an influence in relation to other factors, that influence the strength of a piece of wood (which you would not have with metals).
@@AcornToArabella I’ve watched you since you collected the lead for the keel , made the mould and poured the lead !!! that’s going back a few years. Really enjoy your videos . Thank you very much . I wonder which boat is going to be finished first , Acorn to Arabella or Tally Ho ? You’re on about “on an even keel” 😉 at the moment!!! Thank you again guys,👏👏👏👍🇬🇧
I made a pulley somewhat like that years ago and learned that flat belt pulleys need no sides. If you put them on the belt just tries to climb them and run on top of them. Instead crown the pulley in the middle, it then naturally centers.
@@menow. It's only a generationnal thing. Relax ! 🙄 I prefer this to " I think, aaah, you know, aaaah, the xthing, aah, should go there, aaah, to do xx because, aaah, it will, you know, aaah, work better. 🤣
@@menow. Ah c'mon "Me", is it really that important in your life ? Is her "like" the only important thing important about this beautiful, bright young woman ? Really ? Man, you are in dire need of human values refreshing. Or a night on the town with the boys and loads of scotch ! 🤣
Amazing craftsmanship! I know nothing of this process specifically, yet am surprised the mast graving didn’t incorporate any jointery or at least some sideways support 🤷♂️ also, with that sanding jig, could you loop a belt one end to the other looped around your back so you only have to lean back to apply pressure and your hands can just stabilize and feather the trigger 😸👍
Max bending moment in a lever is at the fulcrum. You need all your wood there. Tapering from there is ok, but if Alix cut it all the way to the fulcrum, it may very well be disastrous. Unless the six inches was way over-designed in the first place.
Hey chaps,The ONLY time I ever broke a spar on Woodwind was the mizzen mast BELOW deck! Bruce Smith..Wizbang from the forum! Cracked from the step to the partner while trying in vain to lift the rudder with the miz boom.(rudder was still locked).
I was worried about losing strength on the mast.... but good explanation on why it’s not necessary.... if it breaks down there you’ve got bigger issues
My mast was tapered from about 10" at the deck to just about 4" at the step. Mast was 55ft over all. Laminated spruce and round in shape. Boat was 33ft 6" overall.
I'm a Lightning sailor and my mast is through deck. When the mast is under load there will be side loads on the step. Any mast bend will be transmitted to the section below the partners. The section between the step and the deck support is a part of the mast and isn't acting like a compression post for a deck stepped mast. I hope you don't do this on the main mast.
With a deck stepped mast all of the lateral loading is placed upon your deck/cabin top at the mast step. With a keel stepped mast some of that lateral loading is transmitted to your keel, but with the deck as a fulcrum point. I know there are naysayers and that the lateral loading, with proper rigging, is minimal; however it still exists. That being said, if what would-be a compression post is, well, strong enough to handle the compressive forces, I'm sure it will withstand the low lateral load placed upon it.
@@michaelgerst1395 A simple mockup of this shows clearly that the mast will most likely break at the transition from full circle to square (assuming the transition is right below the deck level). To be safe, they should have made a taper from full diameter at the deck down to square at the bottom. The way it is set up now it will most certainly have a weak point at the transition site. Key question then becomes whether the deck is strong enough to actually put that much side load onto the mast without breaking itself, which it probably is not. To make this setup safer one could ensure that more of the full diameter section is below deck (further from the point where loads are applied). You do not really need to go far with full diameter below decks, just some 20-30 cm to recover most of the original strength.
Whether the lower square section bends or not depends on the amount of fixity at the deck level. Zero fixity at deck level will allow the lower section to flex. Assuming you have a fairly rigid connection at or just below the deck there should be very little bending below that.
With the Mizzen stepped on the keel and held snugly by the partners at deck level she should strong enough to carry what load she may have, the primary role of the mizzen is to balance the boat's sail plan. If your flying jib and jigger the should sail beautifully.
if the main rationale of cutting off the bottom of the mast was to make more clearance to work around the engine, why did you not just shave off the one side near the engine rather than 4 and make it square ?
That transition from round to octagon to square looks awesome :D How to put a round peg into a square hole? First transition it into an octagon, then into a square...
Based on the original Atkins plan shown in Episode 154, it looks like they have reduced the reaction loads by a factor of at least three by extending the mast at least three times farther below deck to the floor. Think of it like this, if you have a 12’ plank balanced on a beam/fulcrum in the middle with 6’ cantilevered on each side, placing a 100lb weight on one end would need to be balanced by a 100lb weight on the other end which would give you 200lb total weight pushing at the center/fulcrum against the beam. If you move the plank so it is cantilevered 10’ on one side and 2’ on the other, you have created a 5:1 lever. Now a 100lb weight on the 10’ side needs to be balanced by a 500lb weight on the 2’ side which now totals 600lb pushing against the beam/fulcrum. What they have done is this in reverse. They reduced the lever ratio by extending one end of the lever to be closer in length to the other end thereby reducing the multiplication factor of forces at the fulcrum which is where their weak point is with the transition to smaller diameter just below the deck/fulcrum. For example, if originally the mast was 3’ below deck and 30’ above you have 10:1 lever where 100lb force at the top is balanced by a 1000lb force at the bottom with 1100lb force at the deck/fulcrum. Extend the mast to 9’ below deck now you have 3.3:1 lever and 100lb force at top is balanced by 330lb force at bottom with 430lb force at the deck/fulcrum. Given the reduction in forces, i expect the equivalent of a 4” post of fir near the fulcrum/deck is more than strong enough. It’s been 30 years since i took Statics in college so if there are any structural engineers who need to correct me then please do so.
The opening sequence @3:00 to 4:00 where Steve is recapping is outstanding. The finished knees, decking beams and all the bronze fasteners create a image of wooden ship art that one can only appreciate after watching it being created as we (and u) have done. When you watch this video you all must feel a great pride of the work to this point.."It's a boat"... Glad you're taking time off to R&R.
The work Alex has done on the mast fabrication is amazing and is a credit to his patience and skill.
To me, Alix's journey from video guy and helper to boatbuilder has been the most impressive. He's smart and methodical. His segments are often the most interesting parts of a video.
He's engineering some sound solutions.
Agree 100% Ericsuf!!!
he's by far the most interesting member of the crew
What Alix has done with the mast is absolutely amazing!! 💯
Best line this week is Carolyn's: It's all weird shaping....ITS A BOAT!
They need to put that line on a T Shirt...
Yep. That's the truth!
Carolyn,in the previous episode-really like the way you pulled the plank into the rabbit. You're no joke😊
Very nice transition and shape on the mast Alix. At 3:00, the massive knees framing Stephen as he talked looked amazing. What a picture or poster that would make. Thank you all. Take care all.
I like the new intro sequence. I like the shaping of the mast below deck. I cannot help thinking about all the people that have handled that mast, from a tree to Victoria's mast, to the years of maintenance on Victoria, now shaped again for Arabella. A proud history for any piece of wood.
That’s a nice thought, Alan. Thanks for sharing it.
The load transferred to the below deck section of the mizzen mast is not only compression load as indicated in the video. The fibers of the wood will transmit a bending moment about the deck support which will serve as fulcrum for these loads. Forward displacement above deck will translate to rearward displacement below. As the base is fixed, the below deck section will want to bow between deck and base and eventually fail if the load becomes greater than the below deck mast's strength to resist this deformation. That resistance to failure is determined mainly by mast diameter. Hopefully the above deck mast will be sufficiently located by stays to limit this bending load to a magnitude that the thin below deck section can withstand under strong winds and high seas.
Great project, been following you every step of the way. Your commitment is inspiring!
I have never disliked an A2A episode. This one is no exception. As usual, nice work, crew!
Thanks, Bill! Glad you’re here week to week. See ya Friday.
Thanks for posting and sharing! I never knew how complex the shape of a mast is!
Thanks for watching! And there are many more complicated masts out there as well... some racing boats, for example. See you next Friday, lancedaniels.
Bravo Alex! You did a hell of a job on that mast this week. That came out great! Keep the videos coming guys.
That mast is a piece of art.
A MASTer piece ?
@@tomf3150 you beat me to it :D
@@tomf3150 Funny guy ! 🤩
Loving the mizzen mast as it comes along. Alix is in the zone!
Toujours :remarquable travail de spëcialistes ....Un plaisir á voir ...
Mizzen mast with your attention to detail is looking sound and true.
Alex is really showing his skills now. Great photographer and carpenter. Top man.
Happy Arabella day, everyone!
Sometimes i miss the (far)old intro music but nowadays i´m looking cheerfully foreward to the new tunes. Good job Ben!
After all the shaping, sanding and painting etc. i´m cuorius about the test fitting of the mizzen mast.
Does the mast even fit in the boathouse?
@Graham he means vertically, you dingus :p
Nothing like making a very large pencil. Good job Alix! It’s beautiful m
Its going to be a strange transition for all of us when this channel goes from a boat building channel to a sea faring adventure channel. I hope you take us along for that ride when it happens. I've been with you since the keel pour.
Well, hopefully it’s not as dramatic as one day we’re slinging tools and the next minute floating... but I think you’re pointing out how, for most people who want to sail, boatbuilding doesn’t need to be (or maybe shouldn’t be) a part of their journey to the water. It’s so different from sailing! A vast majority of people would do well to just get straight to the adventuring part.
Hope you’re here past the splash, we’re glad you’re watching.
@@AcornToArabella If I'm alive I'll be watching. wouldn't miss you guys and the christening of Arabella for the world. I feel invested in your endeavor seeing all you've done. 👍
Amazing quality of the wood on the mizzen ; the tight grain looks like the top of a Martin guitar . Great work Alex on a difficult shaping job you've really developed your woodworking skills to a high level .
The Karate Kid AND Hatchet Jack AND a Spokeshave Master ! Nice work Alix!
Magnifique travail, Alix. Relève plus de l'ébénisterie fine que de la charpenterie !
Bravo Monsieur Alix ! 👍👏
That mast thinggy... mmmmh. It looks like a very good shear point, very well placed at the fulcrum point.
Great transition. Your skills are growing 👍🏼
That stick is shaping up to be a real work of art. Bravo, Alex.👍
What a team of professionals. Arabella coming together nicely. Well done guys and gal.
really your kidding are you
Feeling a little punchy is so funny. I feel like that when I wake up in the morning. I love watching your videos, it makes me feel a little less punchy lol.
This is one of my favorite things of the week to look forward to. Great work Steve, Alix and team!
One of the most outstanding developments of the build is the impressive amount of confidence you both have gained. You have become real shipwrights and find solutions to your problems instead of becoming mired down in worry.
Thank you, that’s a kind observation. And thanks for watching!
Today on A2A I learned that a tote is not just a tote! I heard the name Roy Underhill which is always a positive thing, and that woodworking is "Just Plane Fun!"
transition looked amazing
I guess even if the mast base thickness was an issue it could be reinforced once it’s in situ but it’s amazing… loved the little demo Steve did with the stick in the hole
This is one of my favorite episodes yet, putting those graving pieces into the mast was soooo satisfying.
Beautiful work Alix 🙌🏻
Alix, great job making a round peg fit a square hole! You made that look easy! 👍
Yeah. this is the best part of any Friday!
Ya'll need to add a coarse thread to the wooden plugs to allow pressure relief as you pound the plug in. That is why you found holes in the mast after you trimmed the wood. If you add the epoxy to the hole prior to hammering the plug in, the coarse threaded plug will allow the epoxy to fill the hole completely while the excess is expelled around the thread.
thanks for uploading
Beautiful, love watching you all
Alix it's a pleasure to watch you work. The mizzen mast is really beautiful. The time you have spent was worth it. I love how Carolyn is so positive and has knowledge under her belt. She is a great part of the rotating helpers. I wonder how many will return in the future. As always another great video. I have watched it twice now. Too bad you can't like it more than once. We are thinking of going kayaking this weekend. It sure has been hot enough lately. Happy Friday!
Happy Friday, Kathy, and thanks as always for being here with us!
Thank you for taking us on this Incredible Journey!!!
Thanks for being here for it!
@@AcornToArabella 100% My Pleasure!!!!!
I have still the intro music in my head everyone i start to see your video
I kind of miss it
Keep on giving arrabella it’s curves looking great!
When Steve walked up to look at the mast at 17:45, I really wanted him to yell "OH MY GOD ALIX, WHAT HAVE YOU DONE??!!"
Always great to visit the progress made on Arabella. Great video.
That's a fine looking transition
I've made a set of reamers (from spade bits) that have the exact shape of various fence or garden stick sharpeners. That way, any bung i put in has exactly the same shape of the hole, and i take out the rot as well. Having a small selection of sizes (first the sharpeners, then the reamers) is a good thing because you only take out just enough, based on the existing hole.
hi guys the boat is looking very good
Being retired military, the last 10 seconds made me laugh. You two are in unison walking back to the boathouse. Says a lot about working closely with someone on a project.
The extra help really paid off.
Beautiful transition.
Much progress, a lot of hard work, great to see the boards becoming a boat. Alex as a woodworker I have found I have better control of a drawknife riding it on the bevel (using the bevel like rudder) and holding the drawknife at an angle pulling it down and sideways at the same time. Maybe worth a try with the Main Mast coming. Fir is a difficult wood to work with, but vertical grain fir should have exceptional strength. I’m already for next week’s episode. Cheers, Will
6:29 wow!!! How clever is that? 😮😮😮😮 ❤
Alix your work just gets better and better and the work on the mast is superb, BUT, at 12.45 there seems to be a terrific difference in cross sectional area from the full diameter of the mast which will be at deck level and the jump in size of the much smaller octagonal section which will go down to the keel. As an engineer, I fear the jump in sections could cause a stress raising area caused by the possible bending of the mast with the deck mounting point acting as the fulcrum and the section below deck at keel level. I saw Steve's demonstration but still have my concerns, however, keep up the great work, cheers from Terry in the UK
"Its all weird shaping, its a boat." LOL :D
Structural engineer here. I think it's important to point out that the mast part below deck will still experience some bending moment. Definitely way less than if it was just a flagpole (i.e. no mid point bracing). The overall message from the little bracing demo is correct, that bracing it at the deck helps. But even in the demo you can see the bottom portion bending a bit. The amount by which it does is related to the relative stiffness of the supports, which is what alix was alluding to when he said it's hard to hold it. The more flexible the top support is (alix holding in demo, or deck structure in real life), the more moment will be carried by bottom portion of the mast. Even assuming ideal (infinitely stiff supports) at the deck and bottom, you have a max moment tapering to zero over the length of the bottom portion. I'm not saying this is dangerous, I'm sure the mast is sized for this. Just wanted to point out that the explanation in the video was a little bit too optimistic. Great video as always, love the content!
It's also good to remember that the original design by Atkin has the mizzen stepped directly on the deck with no part descending to a keel step. But of course you are correct, since the beam (mast) continues below deck and will not be capable of carrying significant bending loads at the deck, it will necessarily carry bending loads between the deck and the keel, just as the main mast will. When stepped on the deck, the deck step carries fore-aft and thwartship loads parallel to the deck and vertical loads onto the deck, while the mast foot simply rotates about some axis perpendicular to the mast line as a result of bending due to sail loading. All of the loading and structural support analysis is quite interesting, especially when seaway inertial loads are also included.
Honestly i would have been tempted to add bronze rods at the corners which would stiffen it up and also help anchor the mast in place more as the mast will lift as well as twist and bend. Plus having easy access to unbolt to remove mast should repairs be required.
Facinating watching the boat building. Never knew how many considerations needed to be made !
@@boooshes thanks for the reply! I forgot about the fact that original plans called for the mizzen stepped directly on the deck. How much further down would you say the mast goes now? Moments scale with the squared distance, so even adding a foot or two of extra mast might lead to a nontrivial increase in moment at the base. Coupled with the fact that the section is reduced down to 4x4 "(plus corner chamfers), and you now have two things working against you. It might warrant a quick re-examination!
Just for my own interest, I'd like to do a "back of the envelope" structural analysis of the mast below deck under different support condition assumptions. Any ideas what sail area the plans call for, and a reasonable worst case wind pressure would be? Only doing a planar analysis, so will of course ignore the much more complex bidirectional bending + twisting load cases.
@@eddiebizi I believe the keel step for the mizzen is roughly 4 feet below deck. You can also estimate by looking at the length of the modified section that Alex produced in the video. The sail plan for the mizzen can be estimated from the drawing of Atkins' Ingrid 38 knowing that the waterline length is an even 30'. I would calculate a maximum wind load at 35 knots on the unreefed configuration with a lift coefficient of around 1.3. HOWEVER, the details of how they will configure the stays and shrouds needs to also be established (which is also represented in the drawings) may be difficult. Note that the main mast is also keel stepped, so will also be subject to similar loadings/reactions/deflection characteristics. Since Atkin was a very accomplished designer, the mast scantlings and step design would have been selected to meet or exceed acceptable design standards of the day, here for a blue water cruiser. Compared to the main, this mizzen should be relatively lightly loaded (albeit smaller scantlings). I found a brief modern paper on mast analysis that is worth a quick read issuu.com/nbaddour/docs/alexbergeron_undergradthesis
Oh, the opportunity to carve some icanthus leaves at the mizzen transition... that chance may be lost now, but hey, It's not my boat. Big beefy transition spots are always a good spot for decorative carvings. Someplace to put some artistic inspiration into your work. But alas, I guess those days are gone for the average workman/workwoman.
That spot, the sampson post, the larger knees, could all be spots for some nice carvings without harming the structural integrity. The few ounces of wood left proud would make no real difference in the performance. The time it takes wouldn't add up to much, in the long run timeframe of the project. I'm not saying adorn the entire ship with intricate carvings everywhere, but a few, here and there, would add a nice old world touch of craftsmanship to this clearly handcrafted vessel. But, again, that is my taste. And also, though it would add to the resale value to the upper end client, this is not my boat, and it is not being built with resale in mind.
I just wish they were keeping the planking watered, those older planks sure are opening up some pretty impressive gaps. I know they will eventually take up again, but you have to keep it from sinking until it does take up. Oils and paint will slow how quickly the boards soak up the water, and soaking them first will affect finish adhesion. Keeping them swollen and letting the surface dry before paint/varnish helps to hold the inner moisture in and slow the drying out. I just hope it hasn't dryed too much at this point. Those seams are going to take a lot of cotton and oakum, but they should still be sealable. My hope is that they find an experienced caulker/corker or two to come show them the whys and hows of doing it the right way for the seams they have. They have put in a lot of work and resources. I want to see it float and sail, when it and they are ready.
Nice work on the mast. If you skew and slice when pulling, it goes much easier.
Lovely work!
Well done
The thumbnail on this video is hilarious! "I love you Mast!" LOL
I miss Akiva's welcoming howl.
Simply incredible
Great work. Thank you all
Excellent stuff dude
Alex should totally take up making chairs after this. Bad ass work on that thing. Wax on, Wax Off Alex-son.
More Akiva!!!! What a beautiful dog!!
Wonderful update, do hope Alix doesn't rough up his hands too much with the sanding though!
If the work hasn't finished yet and you haven't found another solution since, might be worth making a few handles out of scrap wood that you can clamp the sandpaper to with another block of wood and some spare bolts.
Great tip, thanks for watching!
i love to see you guys work on the Boat .. i am a craftsmen by my self (german Metalworker and love wood aswell)
but i dont like the convex transition of the Mast 😁, having a invert corner like that is always a concetration of forces to that point, building it concave evens out the forces over way more area.
i mean you can test it by making to "Sticks" with transitions like that convex and one concave and see what brakes easier and where it brakes.
Just my two cents, keep up with the good work .. eager to see the next Video ^^ have a great Day.
Was thinking the same when I saw the shape. Retired military machinist, always transitioned with a concave shape.
I don't know if that applies to anisotrop (directional) materials.
Where there would be a crack forming into the metal crossection, wood probably just starts to delaminate, .
It is certainly not adding to the strength, but probably not reducing it, like it would in other materials.
Just my two cents though, unfortunately I don't get to work with wood that often.
@@kilianortmann9979 it dosnt matter wich Material it is, it has something to do with the Flow of forces.
so that you can imagine it and to say it easy: Forces behave almost like an liquid inside materials, if the wind pushes sideways on the Mast, the Force aplied spread out inside to the top and the bottom.
Now we come to the Transition, imagine two funnel, one is convex and one concave, pour water in them.
for the concave the Water will flow easy along the edge, but in the case of the convex, the water is diverted to the middle and meets there before it can continue downwards, which causes a back-up.
so for a convax transition with a "sharp" edge at the smaller part like that, you will always have work more force at that spot, even more then at the thicker part, no matter if its metal, wood, carbonfiber or stone.
The only difference in the material is how much the material absorbs itself beforehand.
In Germany we have 3.5 years of education for many professions, especially construction. And physics, the effect of forces is part of every job that is involved in construction.
So nothn i just made up, something i learn in School .. but still a very simplified explaining.
@@georghofmann1782 I know, I had those years and then some on top.
The local forces will be identical for isotropic and anisotropic materials (assuming equal modulus of elasticity).
An isotropic material will fail, where the stress is highest, at the bottom of the notch.
Anisotropic materials will fail, where the local resilience is exceeded, that could also be at a point with lower stress, but also lower local resilience.
core.ac.uk/download/pdf/153229794.pdf, page 56 and 74 say that there is a moderate influence, but the specific shape of the notch is almost irrelevant.
It's still a factor (that's physics), it is just not as big of an influence in relation to other factors, that influence the strength of a piece of wood (which you would not have with metals).
@@kilianortmann9979 well .. then an even easier anser is *better save then sorry* 😁, but thank you ^^
Great job Alex! :-)
Thanks guys 👍🇬🇧
Thanks for watching, Chris.
@@AcornToArabella
I’ve watched you since you collected the lead for the keel , made the mould and poured the lead !!! that’s going back a few years. Really enjoy your videos . Thank you very much .
I wonder which boat is going to be finished first , Acorn to Arabella or Tally Ho ? You’re on about “on an even keel” 😉 at the moment!!!
Thank you again guys,👏👏👏👍🇬🇧
I was in charge of turning spruce trees into "16' pool cues" for our 26' mac (sloop rower). It was very satisfying.
I made a pulley somewhat like that years ago and learned that flat belt pulleys need no sides. If you put them on the belt just tries to climb them and run on top of them. Instead crown the pulley in the middle, it then naturally centers.
That mast is such beautiful wood
Douglas Fir.
I think Carolyn is my new favorite character on this lovely show.💜💜💜
Ours too!
@@menow. I always say like too like! Because im from Cork like.
@@menow. It's only a generationnal thing. Relax ! 🙄
I prefer this to " I think, aaah, you know, aaaah, the xthing, aah, should go there, aaah, to do xx because, aaah, it will, you know, aaah, work better.
🤣
@@AcornToArabella And those eyes of hers !! 🤩😍
@@menow. Ah c'mon "Me", is it really that important in your life ?
Is her "like" the only important thing important about this beautiful, bright young woman ? Really ?
Man, you are in dire need of human values refreshing. Or a night on the town with the boys and loads of scotch ! 🤣
Amazing craftsmanship! I know nothing of this process specifically, yet am surprised the mast graving didn’t incorporate any jointery or at least some sideways support 🤷♂️ also, with that sanding jig, could you loop a belt one end to the other looped around your back so you only have to lean back to apply pressure and your hands can just stabilize and feather the trigger 😸👍
It will be interesting to see it performing in a knock down.
Max bending moment in a lever is at the fulcrum. You need all your wood there. Tapering from there is ok, but if Alix cut it all the way to the fulcrum, it may very well be disastrous. Unless the six inches was way over-designed in the first place.
I'm sure he was leaving it the full diameter all the way through the deck.
Hey chaps,The ONLY time I ever broke a spar on Woodwind was the mizzen mast BELOW deck! Bruce Smith..Wizbang from the forum! Cracked from the step to the partner while trying in vain to lift the rudder with the miz boom.(rudder was still locked).
Cette fille est extraordinaire 👍👍👍👍 bravo bravo bravo 🍾🍾🍾🍾🍾🍾
Now I want a "It's all weird shaping... IT'S A BOAT!" shirt
I was worried about losing strength on the mast.... but good explanation on why it’s not necessary.... if it breaks down there you’ve got bigger issues
Nice video
Thank you
My mast was tapered from about 10" at the deck to just about 4" at the step. Mast was 55ft over all. Laminated spruce and round in shape. Boat was 33ft 6" overall.
Thanks Guy's.
Superbe travail
Stellar as always
“It’s all weird shaping it’s a boat” on a t shirt please.
I'm a Lightning sailor and my mast is through deck. When the mast is under load there will be side loads on the step. Any mast bend will be transmitted to the section below the partners. The section between the step and the deck support is a part of the mast and isn't acting like a compression post for a deck stepped mast. I hope you don't do this on the main mast.
With a deck stepped mast all of the lateral loading is placed upon your deck/cabin top at the mast step. With a keel stepped mast some of that lateral loading is transmitted to your keel, but with the deck as a fulcrum point. I know there are naysayers and that the lateral loading, with proper rigging, is minimal; however it still exists. That being said, if what would-be a compression post is, well, strong enough to handle the compressive forces, I'm sure it will withstand the low lateral load placed upon it.
@@michaelgerst1395 A simple mockup of this shows clearly that the mast will most likely break at the transition from full circle to square (assuming the transition is right below the deck level). To be safe, they should have made a taper from full diameter at the deck down to square at the bottom. The way it is set up now it will most certainly have a weak point at the transition site. Key question then becomes whether the deck is strong enough to actually put that much side load onto the mast without breaking itself, which it probably is not. To make this setup safer one could ensure that more of the full diameter section is below deck (further from the point where loads are applied). You do not really need to go far with full diameter below decks, just some 20-30 cm to recover most of the original strength.
Arrrg, it looks like a peg leg for a very tall pirate.
Whether the lower square section bends or not depends on the amount of fixity at the deck level. Zero fixity at deck level will allow the lower section to flex. Assuming you have a fairly rigid connection at or just below the deck there should be very little bending below that.
With the Mizzen stepped on the keel and held snugly by the partners at deck level she should strong enough to carry what load she may have, the primary role of the mizzen is to balance the boat's sail plan. If your flying jib and jigger the should sail beautifully.
It only gets better. Thank you all.
if the main rationale of cutting off the bottom of the mast was to make more clearance to work around the engine, why did you not just shave off the one side near the engine rather than 4 and make it square ?
That transition from round to octagon to square looks awesome :D How to put a round peg into a square hole? First transition it into an octagon, then into a square...
Hopefully you guys get to the whiskey plank soon ;)
Based on the original Atkins plan shown in Episode 154, it looks like they have reduced the reaction loads by a factor of at least three by extending the mast at least three times farther below deck to the floor. Think of it like this, if you have a 12’ plank balanced on a beam/fulcrum in the middle with 6’ cantilevered on each side, placing a 100lb weight on one end would need to be balanced by a 100lb weight on the other end which would give you 200lb total weight pushing at the center/fulcrum against the beam. If you move the plank so it is cantilevered 10’ on one side and 2’ on the other, you have created a 5:1 lever. Now a 100lb weight on the 10’ side needs to be balanced by a 500lb weight on the 2’ side which now totals 600lb pushing against the beam/fulcrum. What they have done is this in reverse. They reduced the lever ratio by extending one end of the lever to be closer in length to the other end thereby reducing the multiplication factor of forces at the fulcrum which is where their weak point is with the transition to smaller diameter just below the deck/fulcrum. For example, if originally the mast was 3’ below deck and 30’ above you have 10:1 lever where 100lb force at the top is balanced by a 1000lb force at the bottom with 1100lb force at the deck/fulcrum. Extend the mast to 9’ below deck now you have 3.3:1 lever and 100lb force at top is balanced by 330lb force at bottom with 430lb force at the deck/fulcrum. Given the reduction in forces, i expect the equivalent of a 4” post of fir near the fulcrum/deck is more than strong enough. It’s been 30 years since i took Statics in college so if there are any structural engineers who need to correct me then please do so.
Another great vid. gents.
You can get belt sander attachments for grinders that are specifically for doing this