Hobie Cat Forums

It is currently Sat Jul 26, 2014 10:14 am

All times are UTC - 8 hours [ DST ]




Post new topic Reply to topic  [ 15 posts ] 
Author Message
PostPosted: Tue Sep 08, 2009 9:50 am 
Offline
Site Rank - Admiral

Joined: Tue Jul 28, 2009 12:16 am
Posts: 238
Location: HISC Chichester Harbour UK
I am starting on the outline plans for my tramps. Having had a good look at the assorted videos and pictures on You tube and on here, I have decided that I don't want full width trampolines, as I spend a good deal of time pushing myself off the various mudbanks around Chichester Harbour when taking photo's etc. I think Pirates setup is closest to what I am aiming for, a big enough slot down the outside to enable a paddle to get through to paddle or push myself off the mud. Looking at some of the videos, it is very apparent that the tramps hang down a lot with an adult on them. This got me wondering about the loadings being put on the crossbars attached to the hull and the pins holding the Akas on and the stress where they attach into the Amas. My pins are already sloppy in the holes on the Akas and some ovalling is apparent. The additional stress on them wont help and the diagonal brace doesn't need any more loading on its fittings. To that end I am thinking of possibly incorporating the following modifications:
1) Bushing the pinholes so they are a nice snug fit to start with that will hopefully take out a lot of the slop.
2) Incorporating horizontal tubes in the tramps that run front to back between the front and rear Akas on the inside and outer edge of the tramps that will be in compression if there is any weight on the tramp, that will help with the loading on the pins and the Amas. Still working on this. maybe something like a carbon tiller extension fitted into a tube sewn along the length of the tramp.
3) Build in some tensioning straps that attach the front and rear that are sewed the length of the tramps so the tramp can be properly tensioned and will reduce sag with a bod on it.
4) I will also fit some lashing eyes on each tramp and a loose grab strap (based on AIedal's ramblings :wink: ) That can double up as en extra handle when doing a wall of death and to assist climbing back on board when I have fallen out due to the massive acceleration gain from my 18 footer genakker that is next on the list! (just kidding Matt).
I will also incorporate a spray panel on the front to help with drenching factor.

My other thought was to make a hard surface rather than a trampoline that would attach to the frame and be rigid. Maybe using carbon Fibre with a rubbery surface for some comfort. The advantage of this would be that it would stiffen up the entire Aka and Ama setup.

I am still undecided which is the best way forward.

These are my opening thoughts and would appreciate any input. I realise this is leaving the KISS concept, will be expensive and will make pulling the Amas in more complicated, but I think it will have several advantages.

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


Top
 Profile  
 
PostPosted: Tue Sep 08, 2009 11:22 am 
Offline
Site Rank - Old Salt

Joined: Fri Jan 05, 2007 9:21 pm
Posts: 2222
Location: Maui, Hawaii
Maybe something like this:
Image
Image
Image
I use it for fishing and it works great!

This first attempt is not as strong as Hobie's tramps, but I've used it for over a year to hold my gear. It's like fishing with a table next to you. :D

I can also paddle over it for landing.

I've been toying with the idea of buying Hobies Tramps and cutting each in half and sewing an extra strap and clip on each to make two sets that should be as strong as the original, but only half as wide.

Looking forward to pic's of your project.

_________________
Image
http://KayakingBob.com - - - - - Hobie Island Sailing since 2006 - - - - - 2011 & 2012 Hobie AIs and a 2012 TI


Top
 Profile  
 
PostPosted: Tue Sep 08, 2009 11:32 am 
Offline
Site Rank - Admiral

Joined: Tue Jul 28, 2009 12:16 am
Posts: 238
Location: HISC Chichester Harbour UK
That is pretty close! If you imagined those sort of proportions, moulded in Carbon fibre with the tubes integral to the design, with the ends cupped over the outriggers /Akas, it would look similar.

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


Top
 Profile  
 
PostPosted: Tue Sep 08, 2009 11:35 am 
Offline
Site Rank - Old Salt

Joined: Fri Jan 05, 2007 9:21 pm
Posts: 2222
Location: Maui, Hawaii
Wow, that sounds way beyond my dreams!

Go for it :D

I await any pic's

_________________
Image
http://KayakingBob.com - - - - - Hobie Island Sailing since 2006 - - - - - 2011 & 2012 Hobie AIs and a 2012 TI


Top
 Profile  
 
PostPosted: Tue Sep 08, 2009 11:52 am 
Offline
Site Rank - Admiral

Joined: Tue Jul 28, 2009 12:16 am
Posts: 238
Location: HISC Chichester Harbour UK
I am still thinking it through. Seeing your pictures has helped me visualise what I am trying to achieve, it is not far from it. The more I think about it, the more the hard surface appeals. It will help re enforce everything and would probably be lighter than going with the tramp material with all the strapping and tubes I want to include. It would be easy to make a mould to lay up the Carbon Fibre / GP as it would mostly be flat. A rubberised coating over the surface would make it user friendly and help with the UV side of things.

I am also looking at tapered seats and inserts where the pins go with a means of tensioning the joint to get rid of the movement. Have some ideas, but am still thinking it through, there is not much material to work with there.

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


Top
 Profile  
 
PostPosted: Tue Sep 08, 2009 2:41 pm 
Offline
Site Rank - Old Salt

Joined: Fri Dec 05, 2008 2:32 am
Posts: 1773
Location: Calga NSW, Australia
Heavier, but cheap and easy: why not a sheet of (painted) marine ply, with pieces of 2x1along the fore and aft edges to slip over the akas and maybe three more running the length for reinforcement? Not much use for holding gear - everything would slide off.

_________________
Image


Top
 Profile  
 
PostPosted: Tue Sep 08, 2009 3:08 pm 
Offline
Site Rank - Old Salt

Joined: Fri Jan 05, 2007 9:21 pm
Posts: 2222
Location: Maui, Hawaii
If you ever get out in real wind or waves (larger than chop and 12k), I'd be worried at the forces on a non-permeable surface of both water and wind.

I often get a lot of waves pushing up from below and, at times, crashing down from above (hungry waves!). The shade cloth has worked well at limiting water at angles (spray) from coming through, but quickly draining water that lands on it (far quicker than the Hobie tramps). Also the shade-cloth doesn't resist the wind as much.

I'm actually leaning the other way of making the 1/2 tramps or "Hammock" out of criss-cross straps for strength, with shade-cloth sewn over to "close the holes". Only thinking of cutting the Hobie tramps in half as far less work (and sewing).

_________________
Image
http://KayakingBob.com - - - - - Hobie Island Sailing since 2006 - - - - - 2011 & 2012 Hobie AIs and a 2012 TI


Top
 Profile  
 
PostPosted: Tue Sep 08, 2009 3:29 pm 
Offline
Site Rank - Old Salt

Joined: Fri Dec 05, 2008 2:32 am
Posts: 1773
Location: Calga NSW, Australia
reconlon wrote:
Only thinking of cutting the Hobie tramps in half as far less work (and sewing).

Has Dale finally decided enough's enough? :lol:

_________________
Image


Top
 Profile  
 
PostPosted: Tue Sep 08, 2009 3:59 pm 
Offline
Site Rank - Admiral

Joined: Tue Jul 28, 2009 12:16 am
Posts: 238
Location: HISC Chichester Harbour UK
chrisj wrote:
Heavier, but cheap and easy: why not a sheet of (painted) marine ply, with pieces of 2x1along the fore and aft edges to slip over the akas and maybe three more running the length for reinforcement? Not much use for holding gear - everything would slide off.


It would be cheaper and heavier, but that isn't the point. I want to fabricate something stylish and light that will perform several tasks when attached, such as tie-ing the framework together, providing a platform that is strong enough to support an adult either sitting out to help balance (ie me) or for a passenger on it, without them hanging down catching every wave. It will also have tie down points and I was considering moulding in drainage channels to allow water to run off. There is a possible issue of it becoming a wing if the wind gets under it, or a wave breaking over it could also bury it, which I am mulling over.
Maybe there could be mesh windows to break up the flat surface, provide drainage and reduce windage.
The only gear I am anticipating carrying on it at this point would be a couple of Pelican cases with cameras in, which when shut will double up as a slightly raised seat for comfort. I don't find sitting on flat things comfortable these days.

Like I say, work in progress, I am not there yet.

Thanks for the suggestions so far.

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


Top
 Profile  
 
PostPosted: Tue Sep 08, 2009 4:17 pm 
Offline
Site Rank - Admiral

Joined: Tue Jul 28, 2009 12:16 am
Posts: 238
Location: HISC Chichester Harbour UK
Maybe something like this as a basis to copy, lift a mould off it and do it in lighter materials.
http://www.masterpull.com/item.cfm?itemid=47143

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


Top
 Profile  
 
PostPosted: Tue Sep 08, 2009 9:26 pm 
Offline
Site Rank - Old Salt

Joined: Fri Jan 05, 2007 9:21 pm
Posts: 2222
Location: Maui, Hawaii
chrisj wrote:
Has Dale finally decided enough's enough? :lol:

Shhhh!, who do you think would sew the extra straps! :P

rokraider wrote:
I want to fabricate something stylish and light that will perform several tasks when attached...
Definitely a post to follow :wink:

_________________
Image
http://KayakingBob.com - - - - - Hobie Island Sailing since 2006 - - - - - 2011 & 2012 Hobie AIs and a 2012 TI


Top
 Profile  
 
PostPosted: Thu Sep 17, 2009 4:30 am 
Offline
Site Rank - Old Salt

Joined: Wed Nov 26, 2008 4:36 am
Posts: 840
Location: Gippsland Lakes Victoria Australia
In my opinion you guys are definitely all heading in the right direction!
I have a set of half tramps which still need a bit of tweaking before they are useable.
Funny thing is, I am in no hurry to do anything further with them - because I have serious doubts as to their functionality in their present form.
The way I see it is that the tramp material does not drain water quickly enough to prevent swamping from waves over the top and I also think it is likely to magnify the amount of water in the cockpit. In the limited testing I have done so far with them, any waves that come over thetop end up in the cockpit.
Of course all this depends on the conditions you are in at the time. In calmer waters I have no doubt they will help to prevent spray.
Yesterday I decided to just go out using my dodger and found it to be an effective spray guard, as well as provide protection from the sun. (It would equally serve to provide protection from cold winds in different weather conditions.) Although I have been critical of the dodger in the past, I think I will use it far more frequently in future.
The other issue I have with the half tramps is that they incorporate a spray shield like Kayak Bob's, extending from the front aka to the bow. Once again, I suspect that this is likely to magnify the AI's submarine tendencies because it is made with close weave tramp material.

So I would have even greater concerns about designing tramps out of solid material - unless you have adequately addressed the quick drain issue.

It also stands to reason that there will be some increased degree to catch the wind under them - particularly if they are solid &/or don't include vent/drain holes.
The extra space they provide is a real plus - providing it can be done without causing more problems than it solves.
The UK eBay ones are very basic - but given their reasonable price and simplicity, look like a viable option. :wink:

_________________
Mickey
2011 AI Golden Papaya



Top
 Profile  
 
PostPosted: Thu Sep 17, 2009 7:16 am 
Offline
Site Rank - Old Salt

Joined: Fri Dec 05, 2008 2:32 am
Posts: 1773
Location: Calga NSW, Australia
Great Mickey - at last a report on the half tramps. No-one with the standard tramps has reported water being spilled into the hull. Do you think you might be using a less permeable material? Do you think it would help if the tramps didn't overlap the gunwales? Kayaking Bob's sprayshields reduce the tendency of the bow to submerge, but they do drain quickly when water gets on top of them. I was thinking it might be better to keep the sprayshields separate from the tramps, perhaps arranging for them to be attached by press studs. Maybe it would be better to continue using shadecloth for the sprayshields and tramp material for the tramps. Any thoughts?

_________________
Image


Top
 Profile  
 
PostPosted: Thu Sep 17, 2009 3:50 pm 
Offline
Site Rank - Old Salt

Joined: Wed Nov 26, 2008 4:36 am
Posts: 840
Location: Gippsland Lakes Victoria Australia
chrisj wrote:
Great Mickey - at last a report on the half tramps. No-one with the standard tramps has reported water being spilled into the hull. Do you think you might be using a less permeable material? Do you think it would help if the tramps didn't overlap the gunwales? Kayaking Bob's sprayshields reduce the tendency of the bow to submerge, but they do drain quickly when water gets on top of them. I was thinking it might be better to keep the sprayshields separate from the tramps, perhaps arranging for them to be attached by press studs. Maybe it would be better to continue using shadecloth for the sprayshields and tramp material for the tramps. Any thoughts?

Yes! I would feel much more comfortable about the sprayshields using shadecloth. I also think there is merit in having them as an add-on - that you use when the circumstances warrant it.
I believe our half-tramps are made with the normal hobie catamaran type material but from the limited use I have had with them so far, I am not convinced that they drain fast enough and any water on top is directed into the cockpit. Until I can prove otherwise, I believe it would be best to leave a slight gap between the tramps and the gunwhales so the water can be drained before entering the cockpit.
Adding a rigid frame sounds interesting but will make it difficult - if not impossible to fold the akas inwards.
Hope that helps :wink:

_________________
Mickey
2011 AI Golden Papaya



Top
 Profile  
 
PostPosted: Thu Sep 17, 2009 3:58 pm 
Offline
Site Rank - Old Salt

Joined: Fri Dec 05, 2008 2:32 am
Posts: 1773
Location: Calga NSW, Australia
Thanks Mickey. I think you're right - those ebay tramps are looking quick, cheap and simple, especially for someone who already has sprayshields.

_________________
Image


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 15 posts ] 

All times are UTC - 8 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 3 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:  
cron
Powered by phpBB® Forum Software © phpBB Group