Hobie Cat Forums

It is currently Thu Jul 24, 2014 4:21 pm

All times are UTC - 8 hours [ DST ]




Post new topic Reply to topic  [ 6 posts ] 
Author Message
 Post subject: Speeding things up...
PostPosted: Wed Aug 19, 2009 11:13 pm 
Offline
Site Rank - Deck Hand

Joined: Tue Aug 11, 2009 5:04 pm
Posts: 20
I just came across the following tube video
http://www.youtube.com/watch?v=bQRtgEIs--k

and I remember the Hobie Trifoiler. I don't think it would be too hard to make some changes/add-ons to the AI to take advantage of physics:

First off, there are 2 distinct ideas:

(1) use 3 small hydrofoil belt-ons to lift the bow and the the amas to keep them from submerging.
Image

(2) Hydrofoil upgrade kit that lifts the entire kayak out of the water. This would go through the mirage drive shaft:
Image

and of course you would have to replace the rudder with a hydrofoil rudder.

Hobie has a lot of experience with the trifoiler so I hope they will pick up this post and set my crazy head straight

Or else we'll soon be flying AI's across the seas ... ;-)


Top
 Profile  
 
PostPosted: Thu Aug 20, 2009 3:30 am 
Offline
Site Rank - Admiral

Joined: Tue Jul 28, 2009 12:16 am
Posts: 238
Location: HISC Chichester Harbour UK
Interesting concept. How will you trim the ride height? Having a foil on the rudder will change the angle of attack some, but you will need an a aileron of some sort on the main wing to determine the height that it will ultimately ride at.

_________________
Either lead, follow, or get the hell out of the way!


Top
 Profile  
 
PostPosted: Thu Aug 20, 2009 12:29 pm 
Offline
Site Rank - Deck Hand

Joined: Tue Aug 11, 2009 5:04 pm
Posts: 20
I am not sure you would need an aileron. The rudder could look somethink like this:

Image

This way, even when the hydrofoil is all the way up, just under the surface, you still have enough rudder under water. The angle of attack for the front hydrofoils would not differ that greatly between the rudder fully submerged and fully up. There are two forces at work here: the weight of the boat and the amount of lift created by the foils. The lift depends on the size and shape of the foils and on the speed with which the boat is moving. Most of the weight is close to where the drive shaft is, so the rudder hydrofoil can be smaller...

What do you think? Shall we build one ;-)


Top
 Profile  
 
PostPosted: Thu Aug 20, 2009 1:37 pm 
Offline
Site Rank - Admiral

Joined: Tue Jul 28, 2009 12:16 am
Posts: 238
Location: HISC Chichester Harbour UK
I believe It will need to be somewhat more complicated than that. You will still need to be able to adjust the angle of attack and the ride height. I don't think the rudder pin will be very happy with these developments. :wink:

_________________
Either lead, follow, or get the hell out of the way!


Top
 Profile  
 
PostPosted: Thu Aug 20, 2009 3:46 pm 
Offline
Site Rank - Deck Hand

Joined: Tue Aug 11, 2009 5:04 pm
Posts: 20
Oh the good old rudder-pin... forgot...my bad. You are right, this needs a bit more professional approach. But maybe Hobie is willing to look into it. I guess for now I will leave the boat in the water and just lift the bow and amas a little, to reduce the drag they produce... Back to option 1. Later...


Top
 Profile  
 
PostPosted: Thu Aug 20, 2009 4:28 pm 
Offline
Site Rank - Deck Hand

Joined: Tue Aug 11, 2009 5:04 pm
Posts: 20
Now here is another crazy video of a windsurfer on 1 foil !
http://www.youtube.com/watch?v=1oyWMusaDTI

Another thought... how about attaching the second foil through the wheel shaft - same construction as the wheels just with a foil instead ;-). You would have one before the rider and one behind. The rudder still needs to be longer, and maybe that already creates an issue... don't know....


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 6 posts ] 

All times are UTC - 8 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 4 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group