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PostPosted: Wed Apr 27, 2016 2:43 pm 
knight of the folding kayak realm
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Location: inland Pennsylvania, USA
Simon, you can email me directly via the site mail forwarding button. Might be simpler to send pics that way. I really only need a visual of your installed modification. Maybe the seat in the mid frame without the skin if that's possible? Greatly appreciate your patience with this. I have to pack the boat up by May 5 for the trip to Tahoe or I would not be so anxious about it.

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PostPosted: Sat Apr 30, 2016 10:39 am 
lord high faltbotmeister

Joined: Fri Oct 07, 2011 1:51 pm
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Location: Colombo, Sri Lanka
Hi Kerry,

Photos of seat, backband, use of (affermarket) thigh straps and use of rib as footrest are here I hope
http://s1265.photobucket.com/albums/jj516/siravingmon/Quest

Let me know if anything's not clear

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Simon

Pakboats Quest 135, Nautiraid Narak 460, 416 & K1 (sold my 550), First light 420, Feathercraft Wisper, Fujita Alpina AL-1 400, Incept k40 (for sale)
Non-folders: Cape Falcon F1. Beth sailing canoe, 2014 Hobie Adventure Island


Last edited by siravingmon on Sat Apr 30, 2016 8:15 pm, edited 1 time in total.

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PostPosted: Sat Apr 30, 2016 7:49 pm 
knight of the folding kayak realm
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Location: inland Pennsylvania, USA
Thanks! I get it now. It wasn't clear from the earlier small pix that the hose clamp was wrapped around the detached locking piece. Now it makes sense -- you essentially make that clamp movable instead of fixed. I'll drill it out tomorrow and make the alteration.

I like your idea of replacing the seat back. I've got that snapdragon backband in my Greenland SOF and really like it. Don't have time to order one for the Tahoe trip but I will definitely do that when I get home.

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Current:
Feathercraft Wisper
Pakboat Quest 135
Pakboat Puffin 12
Pakboat Swift 14
Greenland SOF
P & H Easky 15LV
Previous:
Feathercraft Kahuna
Feathercraft K-1 Expedition
Pakboat XT-15


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PostPosted: Sun May 01, 2016 4:51 pm 
knight of the folding kayak realm
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Joined: Fri Sep 25, 2009 10:46 am
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Location: inland Pennsylvania, USA
Modification complete! My seat assembly looks just like yours now. Thank you very much, Simon.

After drilling out the rivet I think I see what mistake they may have made in the construction of the seat frame in the early batches of the boat. SInce it is the same connection on both ends, I think they mounted the "hook" assembly backwards after marking the hole where the rivet went (which is closer to one end than the other). Because if the hook is mounted over that hole but in the reverse position so that the shorter length of the seat sling side frames points to the seat front, it mover the rear sling support forward about 4 cm and lowers the seat to a reasonable level.

If I like this position, I may replace the hose clip with a ss bolt or rivet in a hole in the more forward position. Or use a clevis pin and ring so I can change position, and drill a couple more holes to be able to do that. Though I don't know if drilling holes through both sides of the tubing to enable using a clevis pin would weaken it enough to be a problem.)

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Current:
Feathercraft Wisper
Pakboat Quest 135
Pakboat Puffin 12
Pakboat Swift 14
Greenland SOF
P & H Easky 15LV
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Feathercraft Kahuna
Feathercraft K-1 Expedition
Pakboat XT-15


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PostPosted: Sun May 01, 2016 8:11 pm 
lord high faltbotmeister

Joined: Fri Oct 07, 2011 1:51 pm
Posts: 604
Location: Colombo, Sri Lanka
I think you may well be right about the orientation of the clip, Kerry - I'll probably also end up with my hook clip in the same reversed position as yours.

If you decide to make it permanent, I think you should use an aluminum rivet. A small bolt won't spread the load as well, as the forces will be taken by the shank rather than the head (and you want to avoid making the hole any bigger). As a clevis pin won't be a tight fit, it'll move about and work the hole bigger, so you should avoid that solution too.

It's also best not to drill any more holes than you have to due to the high bending loads the support tubes are subject to - I've rotated my seat rails so that the holes are on the sides (the forces are resisted by the top and bottom of the tubes)

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Simon

Pakboats Quest 135, Nautiraid Narak 460, 416 & K1 (sold my 550), First light 420, Feathercraft Wisper, Fujita Alpina AL-1 400, Incept k40 (for sale)
Non-folders: Cape Falcon F1. Beth sailing canoe, 2014 Hobie Adventure Island


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PostPosted: Mon May 02, 2016 12:01 am 
knight of the folding kayak realm
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Actually, after sitting in it for a while at various positions, I like the lowered butt but not the way the front cross bar under the seat is up so high (and eventually cuts into the underside of my thighs) and the feeling of the back bar at the rear.

So, on a guess, I tried my Feathercraft Wisper seat (which is a side to side sling rather than a front to back.) Sure enough, the FC sling fits perfectly with the PB side tubes alone, with the clips removed, slipped into it's sleeves. Once mounted in the frame, I then I attached the one-piece FC seat, which is closed cell foam plus inflatable bladders that attaches with velcro to the sling and is further secured by 1" nylon straps around the rib ahead of the cockpit. I found it works best with the whole seat laying flat. So the FC seat back is laying in the stern under the PB backband, retaining use of the backband built into the Quest. The side tubes just reach to the attachment clips in the kayak skeleton and the seat sits low (hovers about an inch above the keel tube) but without the highly elevated thighs position of the PB seat. If we get a break in the rain I will try this arrangement out this week before final packing for the trip out West.

I think leaving out the PB sling seat will shave some ounces and bulk out of packing the boat for travel too. The FC seat is smaller and more flexible. I may just sew another cordura nylon sling like the Feathercraft one to use in this hybrid configuration so I can stitch on some webbing buckles to keep it from popping out of the frame support clips, I noticed that the frame did pop out on one side a couple of times when I was climbing out of the boat.

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Current:
Feathercraft Wisper
Pakboat Quest 135
Pakboat Puffin 12
Pakboat Swift 14
Greenland SOF
P & H Easky 15LV
Previous:
Feathercraft Kahuna
Feathercraft K-1 Expedition
Pakboat XT-15


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PostPosted: Mon May 02, 2016 12:26 am 
lord high faltbotmeister

Joined: Fri Oct 07, 2011 1:51 pm
Posts: 604
Location: Colombo, Sri Lanka
Thanks fir this. Very interesting...
The front cross bar doesn't worry me as I like to paddle with bent knees, but I do notice the rear cross bar sometimes
Can you upload some photos to flickr? I'd have thought that the arc of the sling would have a smaller radius when across the hull and that consequently the sides of the seat would press into the sides of your hips, especially with a low seat, or that you might sway side to side a bit. If not then I'd be interested in doing this mod
How do you adjust the seat height with the FC sling?

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Simon

Pakboats Quest 135, Nautiraid Narak 460, 416 & K1 (sold my 550), First light 420, Feathercraft Wisper, Fujita Alpina AL-1 400, Incept k40 (for sale)
Non-folders: Cape Falcon F1. Beth sailing canoe, 2014 Hobie Adventure Island


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PostPosted: Mon May 02, 2016 2:57 pm 
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Fortunately, my derriere is narrow enough that it fits between the side rails, plus the foam thickness of the FC seat cushions the sides. I like to have my knees up too, but the geometry of the Quest seat arrangement doesn;t allow me to do that. I'm not that tall but my thighs are very long from crotch to knee and they poke up into the skin too high when I try to take that position with the high cross bar. I can inflate the FC seat bladder to lift my thighs as much or little as I want without the PB cross bar to be in the way as with the original seat.

I've created a Flickr album with shots of how I've installed the Wisper seat. If you click on the album explanation below the title I have an expanded explanation of the shots. It actually fits quite well but I think I am going to sew another sling for it that will add straps to wrap around the Quest lower chine bars. I don't like how those "floating" bars migrate down when the lower sponson tube is deflated and this will not only stabilze them but also secure the seat in place so it won't pop out of the frame supports (which it did a couple of times when I was climbing out of the cockpit.) Upward motion on the seat can pop it out without the clips to lock it in.

My remaining concern is the stress that my weight in the slung seat may have on the side rails and the chance of bending them over time. I just had to spend hours trying to get bends out of the Wisper frame after it was stressed from car-topping it without good support at highway speeds in high winds. I could just make a couple of aluminum tubes to use instead using stock of the same OD. I may even have some in the basement -- I have a crappy pop up shade tent that I was going to give away on Freecycle that may have tubing that would work work for this.

http://www.flickr.com/photos/snapdoodle ... 7808590786

I like that the FC seat can be more easily packed than the PB sling assembly. I plan to bring a little bag of various sized nylon plastic cable ties on the trip to make any emergency field fixes to my modifications. I will probably take along one of my half sheets of ensolite foam. I often lay one of these under my legs in any of my skin on frame boats to protect against pressure on them from the frame parts and also to provide a little insulation in cold water. If my sling seat doesn't work during the trip, I'll just sit on the folded ensolite right in the hull.

The ensolite half sheet also works as a pad inside the boat bag for travel. I lay one inside before loading in the frame parts. And when I do a lunch stop on land during paddling outings, it's nice to have the pad to pull out to sit on when the only options are slimy rocks, wet logs or gravelly beaches. I used to always have a chunk of ensolite with me when I hiked a lot with my outdoor group. My venerable Sacs Millet summit pack had a sleeve under the canvas back that fit the foam insert. On one occasion we used it to wrap around the broken leg of a hiker we helped to evacuate, creating a stabilizing splint over the padding with stout branches and nylon accessory straps.

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Current:
Feathercraft Wisper
Pakboat Quest 135
Pakboat Puffin 12
Pakboat Swift 14
Greenland SOF
P & H Easky 15LV
Previous:
Feathercraft Kahuna
Feathercraft K-1 Expedition
Pakboat XT-15


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PostPosted: Mon May 02, 2016 5:59 pm 
knight of the folding kayak realm
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Simon, I just made a modification that might also help with your Quest . I took I" wide double-faced velcro straps (that I had for binding pairs of Nordic skis together) and wrapped them around the seat frame bars AND the lower chine tube, which I had pulled up to be right at the groove between the two lower sponsons, where it is supposed to sit. Binding these two tubes together keeps the chine tube in the right place and, for me, it prevents the seat frame tube (from which I suspended the sling), from popping out of the retaining clips on the frame bars. I think when I sew the new sling I will make reinforced slits about halfway along the sides so that I can velcro the sling frame in front, midpoint and rear to that chine tube. That will make the seat sling very secure, distribute the weight to both sets of tubes and should prevent the weight on the sling from the paddler from bending the tubes.

If this works well in practice, maybe I will send sketches and photos of the design to Alv since they are working on a new model to replace the Quests and XT's.

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Current:
Feathercraft Wisper
Pakboat Quest 135
Pakboat Puffin 12
Pakboat Swift 14
Greenland SOF
P & H Easky 15LV
Previous:
Feathercraft Kahuna
Feathercraft K-1 Expedition
Pakboat XT-15


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PostPosted: Mon May 02, 2016 9:50 pm 
lord high faltbotmeister

Joined: Fri Oct 07, 2011 1:51 pm
Posts: 604
Location: Colombo, Sri Lanka
Thanks for the pics!

I do like the simplicity of your transversely located sling, albeit with one major reservation: apart from bending the seat rails, my main concern would be the extra stress on the plastic sleeves, which were not designed with transverse loads in mind. If they crack or deform, you’d need to replace the rib, so I’d keep a close eye on this.

Also, tying the seat rails to the chines will transfer the bending forces to the chines AND increase the pressure and so friction wear on the ribs caused by the chines rubbing against the outside of the ribs

Perhaps velcro straps would just give anyway under load, so why not just anchor the ends of the seat rails to the ribs? This would still stop the seat rails from popping out of the plastic sleeves when trying to lift the boat by the seat rails (good idea!) . This is the only time this happens to me, but perhaps there is also a risk of the rails popping out inwards due to the forces on them with the transverse sling arrangement.

I’ll try your system myself next time I’m out, using the Quest sling mounted sideways and with the plastic thigh support sheet removed, then let you know how I get on.
(Edit: I just did a mock up and I think the Quest sling is probably a bit too long to work transversely http://s1265.photobucket.com/albums/jj516/siravingmon/Quest)

PS: In the 2 and a half years I’ve had my Quest, the floating chines have never moved down in use.

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Simon

Pakboats Quest 135, Nautiraid Narak 460, 416 & K1 (sold my 550), First light 420, Feathercraft Wisper, Fujita Alpina AL-1 400, Incept k40 (for sale)
Non-folders: Cape Falcon F1. Beth sailing canoe, 2014 Hobie Adventure Island


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PostPosted: Tue May 03, 2016 12:57 am 
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All three Feathercrafts I've owned have had the seats completely suspended from and supported by the chines. That FC sling installs in the same orientation as I have it in the Quest. The Feathercraft chines slot into molded nylon plastic ribs, but still, the weight on the seat doesn't bend the frame. And I think the FC chines are slightly smaller diameter than the PB ones.

I don't know how I would securely fasten the ends of the Pakboat sling side rails to the ribs independent of the plastic support clips. The rail just barely reaches to ends of the fore and aft support clips. I suppose I could make a loop of a very long cable tie (or two fastened together) and pull it through the rail so a short loop came out of each end, then use short cable ties to connect those loops to the ribs. Or run webbing or strong perlon cord through the rail.

I would argue there is just as much weight and downward stress placed on those plastic sling clips on the ribs by the Pakboat seat assembly as by my retrofit.

Still have some fiddling to do with it.

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Current:
Feathercraft Wisper
Pakboat Quest 135
Pakboat Puffin 12
Pakboat Swift 14
Greenland SOF
P & H Easky 15LV
Previous:
Feathercraft Kahuna
Feathercraft K-1 Expedition
Pakboat XT-15


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PostPosted: Tue May 03, 2016 11:30 am 
lord high faltbotmeister

Joined: Fri Oct 07, 2011 1:51 pm
Posts: 604
Location: Colombo, Sri Lanka
KerryOnKayaks wrote:
The Feathercraft chines slot into molded nylon plastic ribs...

That's a key difference - the FC chines don't rest directly on the ribs so no metal to metal contact so no friction so no wear

Quote:
I would argue there is just as much weight and downward stress placed on those plastic sling clips on the ribs by the Pakboat seat assembly as by my retrofit

The effect of your weight is very different in both scale and direction for each set up. You’re correct in that the downward component of the stress on the rib mounted clips is the same with each set up, but with the FC solution, the clips are also subject to lateral (inwards) loads of a similar dimension.

Here’s why. In both systems your weight creates forces transmitted through the sling to its immediate end supports (cross tubes for Quest, side rails for the FC solution).

Your weight is a vertical load, but the sling can only resist this load in tension, and as the sling angle is not vertical where it meets the supports, only the vertical component of the resisting force is supporting your weight.
This force has two components, like a triangle, with a vertical and a horizontal component, which when added together, act as a vector ( the long side of the triangle) in the direction of the angle of the sling. If the sling is at an angle of 45 degrees where it meets its supports, then the horizontal component is equal to your weight, the vertical component. That’s a significant force

With the standard Quest set up,, this force is passed through the cross tubes to the seat rails via the metal hinges at the front and the (marginal) hook clips at the rear (make sure you use the rubber bands!). The horizontal (longitudinal) component of this force is taken by each of the 2 seat rails in compression and only the vertical component of this force (equal to your weight) is transmitted through the rib mounted plastic half-sleeve clips.

With the FC solution, ALL of the force is passed directly through the seat support rails to the rib mounted plastic half-sleeve clips. The vertical component of this force is the same as with the Quest set up. This is the load the clips were designed to take. The horizontal component of the force acts in a direction (laterally and inwardly) that the clips were not designed to resist and will attempt to prise the plastic clips open.

If you’re still not convinced, try a little experiment; assemble your seat solution on the lounge floor, like this:
Image
Now sit on it and watch the rib mounted plastic clips distort, as I did…

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Simon

Pakboats Quest 135, Nautiraid Narak 460, 416 & K1 (sold my 550), First light 420, Feathercraft Wisper, Fujita Alpina AL-1 400, Incept k40 (for sale)
Non-folders: Cape Falcon F1. Beth sailing canoe, 2014 Hobie Adventure Island


Last edited by siravingmon on Tue May 03, 2016 12:14 pm, edited 1 time in total.

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PostPosted: Tue May 03, 2016 12:00 pm 
knight of the folding kayak realm
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Point taken on the load physics.

My boat did not come with any rubber bands for the seat sling assembly clips. I can make some from an old bicycle tire tube, though.

I think my plan to velcro or cable tie the sling frame to the "floating" chine, which is on the other side of the ribs, could take a significant amount of the lateral pressure off the sling support clips. I may have mentioned I could try shoving the seat frame below the clips and not using them at all. Or I can try to figure a way to replace the support clips with metal hose clamps. I would find some kind of rubber sleeve (probably cut pieces of some sort of hose or tube) to isolate the stainless steel band from the frame tube. Yes, I know they are anodized, but being a career electrician I have an innate horror of galvanic corrosion. Speaking of being an electrician, there are various hanger components for electrical conduit that I may be able to call upon to make a modification to the seat.

Or maybe I can take the frame clips that are now attached to the side rails with the removable hose clips and fasten them to another part of the frame to enable lowering the bow end of the PB sling. I just cannot paddle this boat with my hamstrings 4" above the hull, no matter how far I drop my buttocks in the seat. There has to be a way to make a seat work for me in this thing. For now I will probably just plunk the FC seat directly onto the hull with a chunk of 1/2" ensolite under it.

This design process can wait anyway, until I have more time to test various iterations on short local paddles and work out the bugs. I've decided not to take the boats with us to Lake Tahoe. Despite reassurances from some folks who have paddled the lake in this season, I've realized that I'm not comfortable taking my relatively inexperienced fellow traveler on the trip out in 50-55 degree F waters with just the two of us. Even with proper dry wear, if we run into trouble, she has no rescue training. And we really don't know exactly what our condo facilities will be so storing the boats when not in use might mean having to break them down every day. I think I would rather wait until we can go on a trip to warm waters. She can swap her time share for places in the Caribbean , where the warm waters will simplify the kit and reduce the dangers.

_________________
Current:
Feathercraft Wisper
Pakboat Quest 135
Pakboat Puffin 12
Pakboat Swift 14
Greenland SOF
P & H Easky 15LV
Previous:
Feathercraft Kahuna
Feathercraft K-1 Expedition
Pakboat XT-15


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PostPosted: Wed May 04, 2016 12:09 am 
knight of the folding kayak realm

Joined: Sun Nov 27, 2011 6:09 pm
Posts: 276
siravingmon,

Whoa! Looking at that pic, it seems like that seat is oriented improperly. The left side is intended to face the bow rather than the side. I've been trying to follow and understand all the mods you two are involved with, and no be honest I'm a little baffled. I don't have any difficult just installing the seat as it's intended. Either I'm physiologically disparate from you two or the original seat issue was pretty significant.


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PostPosted: Wed May 04, 2016 6:27 am 
lord high faltbotmeister

Joined: Fri Oct 07, 2011 1:51 pm
Posts: 604
Location: Colombo, Sri Lanka
Your confusion is all too clear :-) If you follow the admittedly long thread, you'll see I'm not recommending the set up illustrated, but rather expressing my reservations about it (Kerry needs an alternative solution for her long legs)

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Simon

Pakboats Quest 135, Nautiraid Narak 460, 416 & K1 (sold my 550), First light 420, Feathercraft Wisper, Fujita Alpina AL-1 400, Incept k40 (for sale)
Non-folders: Cape Falcon F1. Beth sailing canoe, 2014 Hobie Adventure Island


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