Erutan,

The telescoping seems able to get good structural bury and great extension very simply and lightly.  Mike, et. al. Any thoughts?

  I mentally have a tough time contemplating telescoping beams because of my experiences with my current trailer.  Plus the look is non-optimal.  Not just the profile, but also from above -- I'd like beams that aren't parallel, as shown in a lot of the older harry's, and scissors (or the Ex40 renderings) can handle that.

  That said, I'm a bit of a problem child in this area, and I have a feeling I'll be in the minority.  The scissors are going to weigh more, plus are going to cost twice as much.

So lets just assume tillers?

Definitely. And with telescoping extensions.

Mike said this was preferred anyway, IIRC.

  It won't get simpler, less expensive, lighter, or less failure-prone than tillers, especially if you're folding on the water. 

  There are no cables to tighten, or which might hop off a quadrant, no hydraulics to maintain or leak, and nothing to remember when you're folding (if you forget to collapse the tiller extensions, the worst thing that happens is that you then do it).  And nothing to disassemble when transporting the boat or dismounting it.  Perhaps two cables -- one for communications/electronics, one for power.

  I"m also quite partial to tillers for steering.  I always feel like I'm sailing with tillers, but often feel like I'm driving a bus when I'm on a wheel.

So, if Mike is a once a season guy, Arto is a cruiser, and I am the 2 hour guy. How does optimizing for me tick the other two off?

  I think it just enlightens us and expands our horizons of what's possible.  Besides, if it works for the 2-hour guy, by definition it's going to work for someone who stays in a marina for a few days, or someone who folds/expands a few times per year.

Are there any we have not addressed? Or not addressed enough?

  I may have had a brain pause on the tender-mounted outboard motor.  It's a brilliant design, but I'm not sure how it would work when the boat is collapsed/folded on the water.  It's probably not a show stopper for trailering if you have a boat ramp where you can tie up for five minutes, but you'd definitely want a working motor when finding a slip in a marina.

  Maybe there's just enough room between the hulls when the boat is down to 12' for a narrow-ish catamaran tender with an outboard.  But then you'd have to detach it from its normal beam mount and reattach in the new position.

  Unless you have telescoping beams, and the leeward section is the lower section (or outer section, depending upon the design), where the tender attaches.

  Hmm.  I still want the darn scissors folding mechanism, but I probably care more about the tender/outboard than I do about the scissors.

  The other option I'd contemplate would be a well inside the lw hull for an ultra-long-shaft outboard like the Presto 30:

    https://youtu.be/4pJ1j5GW78c?t=71

  But there's a lot more to be said for the simplicity of the tender/sled, as well as for having a hard tender onboard all the time (and an easy way to load/unload).

Lowest beam to windward, and highest to lee?

  Probably the opposite if we want the tender to work when the boat is collapsed.

  Though if one side is lower, putting that side on the lw hull, which is being pushed down into the water when loaded, is a bit backwards.

  Maybe inner/outer telescoping beams instead.

Can those beams get good strong bury to each hull and still let the other beam slide in that deep?

  Likely.  The forces are known, and there's that big cabin/cockpit area to allow for a good amount of overlap.

  One a related note, I've always worried about telescoping beams creaking and working things loose over time when subjected to rough weather.  I never though the joint could be tight enough for a solid total structure that resists wracking, while still being loose enough to allow the beams to expand and contract.

  But what if we had some of those big screw-in pins from the cat2fold mechanism that fasten using a winch handle?

 Would 0.5 mm clearance still allow for easy telescoping, particularly with a UHMW PE surface, and yet also be small enough to allow the system to be tightened down and solidified without damaging the structure?

  Maybe if the beams overlap like Rob's latest image, then it's a non-issue.  The sleeves could be loose-ish, and then the pin mechanism could really pull the upper and lower sections together to make them behave as one.

 But that brings us back to having the lower beam sections on the lw hull.

  I suppose I'd lean towards an inner/outer telescoping mechanism as long as it could be tightened well.


        - Mike

  | See attached. If not, let me know and I will put it in the Files.

| The white straps can have plastic inserts or balls to run smoothly, or someone sitting on the boom to leeward of the lee hull to take the weight off.

Honestly, that's very sexy. Closed, light, and very simple.

Does this even need internal lines? Can they not all just be external? Address's the maintenance. Show off how stupid simple it is?

(Side note, no reason I could not build for my E25, to test?)

Perhaps UHMWPE as bearing surfaces?

Can 2 almost 12' beams that go almost to the outside of each hull get us to ~22’? If I did the maths right.

Can those beams get good strong bury to each hull and still let the other beam slide in that deep?

Perhaps need a 3rd beam to get the width to 25'+?

Lowest beam to windward, and highest to lee?

Perhaps if we get the beam lengths dialed in, we can get a final length, then we can start seeing how the parts rack and stack?

| Complicated indeed, but the pros and cons of each are pretty clear.
| As are the compromises that need to be made.

Are there any we have not addressed? Or not addressed enough?

The telescoping seems able to get good structural bury and great extension very simply and lightly.

Mike, et. al. Any thoughts?

| > So lets just assume tillers?
| >
| Definitely. And with telescoping extensions.

Mike said this was preferred anyway, IIRC.

| > Can the toy box and winches be removable and also still hold the anchor well when anchored?
| >
| Yes.
|
| >
| > Any ideas?
| >
| Several, but they are all compromises. Need to decide what is important..
| If you are opening and closing the boat either side of a 2 hour sail after work, the requirements are different to taking it apart to take it home once a season.

Tell me more.

A third target is the cruiser who wants a mono slip, perhaps? Call that guy Arto?

So, if Mike is a once a season guy, Arto is a cruiser, and I am the 2 hour guy. How does optimizing for me tick the other two off?

| > How about when collapsed can the bench seat slide over the lee hull? That eliminates the storage under them I guess.
| >
| Yes and yes
|
| >
| > Or just make the benches removable as boxes, to keep the storage? Assuming they are not a structural part of the lee cabin wall.
| >
| They aren't, but they have to be put somewhere, as does the tender and anything else removed.

Trailering, perhaps the bench boxes and toy box may stack under, fore, and aft of the boat. Put the T40?? On its side impaled on its lifts by the gin poles or mast stubs?

How high is the lee hull? Add the T40 width and 33" for the trailer. Are we under 14'?

If you are in a slip and you got a T40?? where do you put it? Can you just tie it behind your boat? Will it fit under? Swamp it, and slide it under in the slip? Same with the boxes?

Will the boxes float under the boat? Perhaps not the toybox.

I hope I didn't embarrass myself too much.

__._,_.___

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Posted by: Mike Crawford <mcrawf@nuomo.com>

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