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allweather

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Posts posted by allweather

  1. Basically that, in uni, if not for overall cost and shipping getting rather prohibitive...
    I did some napkin calcs that come out quite a bit cheaper, especially when I buy leftover fabrics from outlets which is more than enough for my purpose. Well, my time not included, but that I can live with...

    Right now I am testing(once I'm home again anyway) if the bearings I picked up work as I envisioned, then gather the other materials...
    Though I am playing with the idea of using uni directional glass in most areas. For all that carbon fiber is miracle stuff, as I understand it at the lower end strength to weight ratio the difference isn't that big, but carbon still vastly outperforms in terms of stiffness no matter the grade.

    But since I don't necessarily care too much about the straight parts bending, I need to consider if it's worth the cost for me there. Different for the "outrigger" that takes a lot of torque, biaxial carbon seems the most useful there.

  2. I'm no specialist, but this promotional video of a company using the stuff boils it down to not using traditional tows and instead a special way to spread out fibers that results in less voids and hence less weaknesses from how I understand it as a total layman.

     

  3. Thanks for the additional advice on what to ask for at a machine shop! In particular the part about 3-4x diameter is great to know for discussing with the machinist.

    The pod casing itself is metal, I suspect aluminium but don't know for sure.(no manual for that, only know that the original shaft was proper stainless steel) So I don't see myself trying to fiberglass anything there, screwing seems more convenient too...

    It is basically a trolling motor like all the others(there are threaded M30 fiberglass shafts around, but as mentioned, I want to go a bit slimmer)
    I agree with you on the fairing, the current plan is to go for a 20x40 oval. Which while not ideal at all as far as drag goes, is the compromise I need since this part telescopes into the upper section which in turn needs to fit through slide bearings.

    Way more complicated than a basic fairing and small bearings to turn the motor, but the only way I was going to fit through the hatch and still reach deep enough into the water to be of some use even in a bit of waves. Sure, won't do me a lot of good in more than a meter or so in wave height, but then that is always like that with outboards. As is it is already at least as deep if not moreso than the long shaft Suzuki.

    But I am digressing. Thanks for the advice on how to go about it again! Now I just need to find a machine shop with some time and patience ^_^

  4. Oh, I'm sorry for my in retrospect very unclear question. Can only partly blame my grasp on the language...

    When I say shaft, I mean the straight pipe that connects the pod/motor with the outrigger.(aka, what a long shaft on a petrol outboard is)
    That kind of load should be addressed with normal, straight uni directional fiber, correct?

    I am reasonably secure in choice of tubing there(considering I currently am using uni directional glas fiber...), what I am not sure is how to best enlarge the diameter for the larger threads used to connect that tube to the pod.

    So, barely any torsional loads at all and pretty much all transverse loading if that makes sense?

    As for the thrust that then acts on the tube, it is nominally 60kg thrust produced from a 1,2kW motor. So nothing much.

  5. After gaining some much needed experience last year and busy with other projects over the winter I now want to redo my diy electric outboard construction. This time in carbon to save some weight and get it stronger at the same time, but mostly to get some adjustments in(needs to be 20mm smaller to pass the backstay adjuster effortlessly) and insert some proper slide bearings.

    To that end I want to replace the 30mm/M30 stainless shaft that comes originally with a 19/12mm Carbon shaft(don't want it thicker than that) and would like to hear if anyone has advice how to best get an M30 thread on that shaft.

    Ideally I'd love to get it in G10, but don't even know where to find something like that in Europe, so my next step would have been to have a stainless piece machined that I then can glue onto the carbon shaft. Which isn't great, but okay.

    Ideas?

     

    Picture is how it is right now, I want to have the next version to be slimmer and smaller overall so that the round/turning part can use 60mm slide bearings that I have found relatively cheaply and readily available.

     

    2021_04_08_IMG_3454.thumb.JPG.56024bb3685687f71f651dcb815bf13a.JPG

     

  6. 10 minutes ago, Diarmuid said:

    PV square footage becomes the limiting factor: in my experience

    Way I see it you can already mount panels on your dodger, between dodger and mast(not perfect, but works!) and if you wanted to even on the bow hatch. Unless that is one where you get/need light from?

    More importantly, nowadays the electrics should come with regeneration of some sort. As per your preference to sail, that should give you a lot of opportunity to recharge when you have more than... 10 or so knots. Yes, drag is a thing but compared to what it takes to drive a boat through the water at higher speeds, it may not be as bad as one could fear.(unless at low wind and speed, then of course the small watts make all the difference)

    • Like 1
  7. 2 hours ago, JulianB said:

    And yes these are 49er profil shape, but WRT the 49er, the size of the carbon makes it quite hard to do this, plus the way we designed the shape of the foil, we basically rendered feathering not worth the effort

    You know, I am here to watch the awesome boat take shape and see what new, cool methods you use, but you could just as well write a 49er blog and I'd read it all the time. Fair on trade secrets though.

    It's not like I have expertise or am ever going to use it(probably), but darn if these insights aren't super interesting in addition to the normal build. Certainly widens the horizon.

  8. 6 hours ago, IanA. said:

    Cooler heads prevailed regarding the spreader tips

    Happy sanding ;) Some extra steps, but sounds sensible to add that extra bit of strength instead of relying solely on the glued joint.

    Always surprising how small'ish rigging gear, like the mast jack, can look for the loads the things can see sometimes.
    Just like with the forces on even 4mm rigging wire, not something I can get intuitively...

    • Like 1
  9. 5 hours ago, JonRowe said:

    and give you the ability to tilt the panels to the optimal angle to get the best sun

    I missed that they actually adjusted the panels for better yield! The surfmast base makes a lot of sense then! 

    As do the further explanations regarding ease and cost that is basically unbeatable. 

    And yes, my though essentially went to an arch, connecting the two tubes or the like, which in retrospect is not necessary and would get in the way of tilting.(needing more panels, price and windage to compensate)

  10. At cost of fitting is a very pleasant calculation. In the meantime I also realized that with the hydraulic jack unloading the rig is super easy and as such creep not as much of a concern. Or the length change when temperatures fluctuate. 

    That was the main reason why I was thinking carbon, to avoid the differences between mast and shrouds. 

    This plan makes a lot of sense, especially the dialing in part. 

  11. Seeing those pictures with virtually any mini having the two panels in the back, isn't there a small market for a standardized arch?
    Or is this just a case of sounding like a possibly neat idea at the bar, but on paper is actually 500g heavier and thus a no go? Probably with how much work goes into some campaigns...

  12. It's very nice to see the somewhat rough looking appearance of the fabrics!

    I take it this is a case of not bothering with work or weight to get a smoother finish when its all about function here? I like that practical approach.

    Also just neat to see the foam tape method you described earlier in action. Pictures make visualization easier and it is something I've committed to memory for future endeavors where I am sure it will come in handy!

  13. 5 hours ago, IanA. said:

    The idea with starting oversize is to ensure good shoulder bearing of the block against the edge profile of the spreader body.

    Makes sense, thanks for expanding on the plan.

    5 hours ago, IanA. said:

    This factory is churning out heaps of carbon composite products weekly which also generates a certain percentage of offcuts/ wastage that can actually be used in building up plate material. And then combine the buying power of that much raw laminate every month and the fact that you have an autoclave running near daily regardless, making and using carbon plate is actually the most economical choice.

    Very different to two dollar garage operation!
    Makes a lot of sense to use first the left overs(prepreg anyway, right? Thought dry fabric clippings have some recycling nowadays whereas resin makes everything difficult)

    Also, if I could choose with no other consideration, carbon is nice to have...

    4 hours ago, IanA. said:

    Its not the end of the world if I have to re-tap new holes and fill the old ones but it would be nice to get it right the first time... 

    Fingers crossed. Really like the idea of the hydraulic jack, so that is nice to see come together!

  14. Neat, you are going to shape them some more once everything is bonded?

    Also, I've always been curious about using carbon as a block like that considering the cost. Sure, it is light and strong, but are there any specific advantages here instead of using... glass or some plastic tips?

  15. 11 minutes ago, SloopJonB said:

    they work like magic.

    I like the utility, but don't think I ever saw why not to use a pantograph for the same purpose? Seems like another step in convenience, or am I missing something?

  16. Ah, I was thinking more of stiff/tender related to hull shape(which I suppose wet area/design displacement would go into)

    That said, I don't think I remember a boat where reducing keel weight was ever necessary for performance?
    I mean, reducing mass obviously increases performance if it is "surplus" stability/righting moment, but just having more righting moment due to a lighter mast isn't ever a negative compared to the same boat with a heavier mast, is it? Apart from comparative gains to be made from additional changes.

    1 hour ago, IanA. said:

    Ultimately we will need to sail the boat and learn better what she really wants.  

    Makes sense to me. With all the things you have changed it should be quite something to try out and see how she handles once out there.

  17. 18 hours ago, IanA. said:

    I am just finding it so funny when man handling it around on my own with no major issues.

    Carbon is awesome like that, if not for class rules/convenience(and well, money) I would love to opt for the option.
    Though to be honest, H-boat mast is small enough that a single person can still carry it easily(even a light weight like me) and stepping isn't that much of a hassle.

    Still, would be nice considering the handling even before sailing advantages...

    18 hours ago, IanA. said:

    Only big question plaguing me now is that if the boat is too stiff with these updates,

    What do you mean with this exactly? I know of the effects the weight reduction can cause, but doesn't that include a decrease in stiffness/increase in responsiveness and why would less heeling moment be an issue that makes you think about keel reductions?

    I may be a bit confused with the terminology.

  18. Good to know, just keep stitching then. Though I may get away with skipping the stitching for testing purposes until everything fits and then do it after the fact...
    Well, shrouds are all wire for now anyway.

    Hm, better to just stay on the safe side and put in a toggle then. While I don't have plates and actually round attachment points the terminations can rotate around in two axes, within reason sideways, it is hardly much of a bother, if a few gram more. Only the forestay is an actual flat plate that would torque.

    Bigger annoyance is the Selden T-eye that doesn't have a proper data sheet on ropes to use/break loads, but that is a different headache.

  19. 11 hours ago, JulianB said:

    I can elaborate next week,

    You're always welcome to, will be a happy reader. But what you've posted already(or in other threads) is plenty too.

    As is some of what you describe is outside of what I can achieve on my current keelboat. Not the fairing as such, I'll do that next time antifoul is off. But since I am trying out antifoul (silicone) foil this year a certain... structured feel is there no matter the surface prep. (of course the primer got screwed up, some runs, and no time to fix before hitting the water this season... Next time)

    That is great to know about vertical flow! Putting that into practice... as you said, when I find the time and it isn't windsurf/skiff weather ;)

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