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  #91  
Old 10-11-2016, 04:03 PM
jorgepease jorgepease is offline
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Quote:
Originally Posted by Richard Woods View Post
Security is always an issue with a layout like the Rapier 400. You cannot lock up the cabin so sensibly cannot leave anything in the galley when alongside, or even at anchor

Richard Woods of Woods Designs

www.sailingcatamarans.com
Yeah, I agree on that, why tempt somebody.

This is the video I mentioned with a snippet of infusion at 1:10 - https://youtu.be/oLSdZNRXnvk

Not sure what those ribs are (BulkHead Landings?). If so why don't they extend further up.
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  #92  
Old 10-14-2016, 08:51 AM
rob denney rob denney is offline
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Quote:
Originally Posted by groper View Post
Rob, I'm all for the box molded shape except for 1 thing. If the forefoot of a hull has a flat bottom it pounds in a seaway. The slamming gets pretty annoying and I wouldn't build another boat with a flat bottom forefoot again. It's not about the minimum wetted area thing, the modeling I did in michlet and with a wealth of information on the subject by professionals here- it's a given that virtually any shape with a reasonably fine entry and constant displacement to length ratio will have nearly identical resistance curves.
It is more work, but not difficult to include a round or V'ed forefoot with a box mould, either pre or post infusion. However, my preferred solution is a rockeries hull, which is more pitch resistant, potentially faster and easier to build. Not as easy to tack (although John Hitch's Wired apparently had no trouble), but that is not a problem with a harryproa. If you did put a shaped bow on it, I would still recommend a flat floor further aft.

Jorge,

Pretty sure those are partial ring frames, not bulkhead landings.
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  #93  
Old 10-16-2016, 03:35 PM
jorgepease jorgepease is offline
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Originally Posted by rob denney View Post

Jorge,

Pretty sure those are partial ring frames, not bulkhead landings.
Yeah probably so but I think that concept would work well. It might require a trim on one side to make look right but I think it's the easiest way because you have a little play.

I was playing with Graingers Flying Fish 50, assuming an open cockpit, I stretched the bow 5' and the stern 5' without touching anything else. That shouldn't add too much cost, looks awesome and probably increases the amount of stuff you can carry without losing performance.

Here is a look at them together
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  #94  
Old 10-17-2016, 01:13 PM
jorgepease jorgepease is offline
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Been contemplating retractable elec. sail drives or just elec. outboards connected to a portabracket (24" movement). I inquired about shipmotiongroup retractable drives. They are nice but wow!!

Quote:
Thank you for your interest in our Retractable Propulsion Systems.
Our small Retractable Systems will suite the torqeedo hybrid systems. Looking to financial numbers you should count with approx. 350000,- for 2 systems including structural parts and control system.
I don't think that counts the Torqeedo's, which means just one retractable unit costs more than the entire torqeedo system - 2 motors with batteries and controls .. lol who would pay that??
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  #95  
Old 10-18-2016, 03:27 AM
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waikikin waikikin is offline
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Originally Posted by jorgepease View Post
Been contemplating retractable elec. sail drives or just elec. outboards connected to a portabracket (24" movement). I inquired about shipmotiongroup retractable drives. They are nice but wow!!



I don't think that counts the Torqeedo's, which means just one retractable unit costs more than the entire torqeedo system - 2 motors with batteries and controls .. lol who would pay that??
That is wow, must be a typo on the zero because I want the whole boat or a large percentage for 350K euro..
Jeff
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  #96  
Old 10-18-2016, 07:13 AM
jorgepease jorgepease is offline
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yeah, 35K might be doable, I can't see them getting too much business at 350K. Schionning posted this guide on Facebook, right up there with the material cost of a 15 meter cat

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  #97  
Old 10-19-2016, 12:03 PM
jorgepease jorgepease is offline
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A cat with daggerboards can have as little as 2' of draft, I don't want to ruin that by hanging motors off the bottom.

Since I intend to use electric, I just had an idea, why not mount them on the sides of the hulls like this mini sub.

EDIT: Ok I just heard back from Torqeedo and they believe it would be okay as long as hull is reinforced in that area. I think I just found my solution!!

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  #98  
Old 10-24-2016, 06:22 PM
sailhawaii sailhawaii is offline
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I think mounted on the side, you will have issues with the prop coming out of the water, unless mounted mid ship where you could get them deeper. My thinking was to mount them on a kick up box on the last transom step that also had the rudder attached.

BTW here is a thread to the catamaran plan I'm working on:
45' Cruising Catamaran Project

My current plan is to release it Creative Commons (meaning free). I will have all the CNC cut files for the panels as that is how I plan to build it.

I'm not very far on it and currently making lots of changes based on feedback I've received.

-Bryan
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  #99  
Old 10-24-2016, 08:12 PM
jorgepease jorgepease is offline
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Quote:
Originally Posted by sailhawaii View Post
I think mounted on the side, you will have issues with the prop coming out of the water, unless mounted mid ship where you could get them deeper. My thinking was to mount them on a kick up box on the last transom step that also had the rudder attached.

BTW here is a thread to the catamaran plan I'm working on:
45' Cruising Catamaran Project

My current plan is to release it Creative Commons (meaning free). I will have all the CNC cut files for the panels as that is how I plan to build it.

I'm not very far on it and currently making lots of changes based on feedback I've received.

-Bryan
I saw your thread, I like the look but I know very little about what makes a good Catamaran, keep bridgedeck high, nice big tramp up front, weight to centers, etc etc... just what I read but it's a great project. I downloaded Rhino and have been fiddling with it but think it might be overkill just to edit cut files.

Yes on the motors being mounted amidships, boat has a draft of about 2' so plenty of water. The other option would be as you say, on the stern with maybe a portabracket to raise and lower but I'm a bit worried about theft in that case.
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  #100  
Old 10-25-2016, 07:52 AM
jorgepease jorgepease is offline
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a little bigger motor and this might work https://www.youtube.com/watch?v=j7rH...ature=youtu.be
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  #101  
Old 10-25-2016, 08:14 AM
redreuben redreuben is online now
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Rudder motor

Quote:
Originally Posted by jorgepease View Post
a little bigger motor and this might work https://www.youtube.com/watch?v=j7rH...ature=youtu.be
Devlin's Nancys China has been using that idea for decades now, not sure if he is the original, it's a cool idea if you can except the small drag penalty.

http://store.devlinboat.com/nancyschinadc.aspx
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  #102  
Old 10-25-2016, 08:48 AM
jorgepease jorgepease is offline
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Originally Posted by redreuben View Post
Devlin's Nancys China has been using that idea for decades now, not sure if he is the original, it's a cool idea if you can except the small drag penalty.

http://store.devlinboat.com/nancyschinadc.aspx
Also, it seems the problem of having the prop aft and popping out of water in seas, would remain.
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  #103  
Old 10-25-2016, 09:02 AM
redreuben redreuben is online now
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Quote:
Originally Posted by jorgepease View Post
Also, it seems the problem of having the prop aft and popping out of water in seas, would remain.
I guess that would depend on how far down the rudder you installed it ?

A big cat is going to have a much deeper high aspect rudder than the little mono.

It may even fit in the junction of a T foil rudder ?
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  #104  
Old 10-25-2016, 09:03 AM
redreuben redreuben is online now
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Uh Oh I said the "F" word !
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  #105  
Old 10-25-2016, 09:40 AM
jorgepease jorgepease is offline
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There might be one drawback - The idea of keeping the prop up above bottom of boat is so I can motor in the shallows. In these cases, the rudder would be up.
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