Uni-wale?

[Rick]

Randy and Moonman... I was planning to bolt the seat directly under the inwales, without any drops... the center depth of the solo hull is only twelve inches and that doesn't leave much room for kneeling paddlers to slide feet underneath (at least those with big feet). My other canoes have eleven inch clearance under the seats and that's still clunky with boots on.

My guess is the solo will be a bit tender at times because of it's narrowness, so the need to keep the center of gravity low can be done by kneeling when the waves kick up. If the paddling is all done sitting, then the seat can be mounted lower down with bolt drops or cleats. I like to switch positions often for comfort, from kneeling to sitting, sometimes sitting on the bottom with my back propped up on the seat edge for a rest stop, so the seat needs to bolted on higher.

With the seat bolted on directly to the inwales, the crossmembers could act as a thwart and the need for a thwart behind the seat might not exist... the seat crossmembers will flex a little with sitting, but the flex in the hull should be enough to allow this.

The seat location may need to be changed with time, so that's another reason to use bolts in the inwale. Some sort of sliding arrangement could also be built in under the inwale, to change trim as needed.


Anyway, some thoughts only at this time.... I'll probably build my solo this way.

[Patricks Dad]

I finished my seat install today (the frame anyway, seat still needs cane). I ended up with 1" spacers at the back of the seat and 1-1/4" spacers on the front edge. This leaves me with a clearance below the front seat rail of about 8.5". This is a bit on the low side but I'll see how it feels when I paddle it (I can always shorten the spacers). Even at this height, I should have plenty of headroom though for a yoke the ties in with the seat.

I came up with an arrangement to fatten the uni-wale in the region where the seat mounts (a couple pieces of cherry shaped to the curve of the uni-wale and connected to the uni-wale with biscuits and epoxy. I used threaded inserts on the bottom of these flanges to mount the seat from below. No signs of hardware unless you look directly under the seat.

I put in 2 sets of threaded inserts so the seat can be positioned in either the design position or 3" aft of there. It was kind of tricky to get them in exactly the right place so the same seat would work in either position. I'm satisified with how it looks (still some rounding of corners to do, etc... In the future, I could convert this into a sliding seat by using those threaded inserts to support a slide rail...(no current plans until I see how she paddles).

Here's a picture.




Next step - some cane on that seat and a crack at a yoke.

[Moonman]

Hi Randy,

Any new progress on the boat? Did you actually come up with anything for the integrated yoke/back rest? Your decks look great.

Moonman.

[Patricks Dad]

Moonman,

Here's what I came up with. It's not quite done yet (still needs a couple straps to support the backrest configuration) but I think it will work (kind of ugly). It weights about 1.3 pounds. It reconfigures quickly (I'll post a youtube video when completely done but I expect to meet my 10 second requirement). The "out-rigger" pegs that catch the gunwales for portaging are connected to each other via a rack and pinion arrangement inside the tube so when you pull one out, the other extends automatically by the exact same amount. The "landing zones" ensure that the yoke configuration hits the right place for a proper balance independent of where the seat is positioned. I'm planning on magnets to hold it in those landing-zones. The "reach" for the yoke is pretty long. The balance point on the Freedom Solo is about 9" in front of the design seat position and I've allowed for the seat to be moved back 3" - a 12" reach beyond the seat required.

In the backrest position, it will have adjustable stops to allow you to pick the right height (although all might be a bit on the high side obviating the need for any adjustment at all). The distance between the pads was a trade-off between proper width for shoulders for yoke and shoulder blades for backrest. I'll know how well I did after I use it for a few days (need that ice to melt!). It may need to have a sliding arrangement to allow for different spacing for yoke and backrest?

http://www.facebook.com/photo.php?pid=6 ... =573157884

You should be able to go forward and backward to see a few pics of the design...

This is my first experience with carbon fiber. It was fun (but not cheap!).

[Patricks Dad]

It appears that we have a new forum "look". It also appears that posts from today (at least those on this thread) are gone! The last post I put on this thread included a link to the entire album for my build (in response to a post - also missing - from Moonman).

http://www.facebook.com/album.php?aid=2 ... d0ba2b0a14

[Moonman]

Hi Randy,

I was wondering where my post went!

Nice look to the new forum setup though. Nice to see the additional backrest/yoke pics. Really practical approach. Whereabouts do the backrests touch on you back when sitting?

Moonman.

[Patricks Dad]

Finished the boat yesterday and took it out for it's first portage today to test out the new yoke/backrest design. No water to paddle on however....








Here are a few additional pictures of the detail of how the yoke works...

Landing zones attached to Uni-wale to capture carbon fiber tube on yoke:


magnets on end-caps of yoke tube align with magnets on landing zones...





A gear mechanism inside the yoke tube ensures that both tubes go in and out in tandem. When you push one side in to contact with the magnets on the landing zone, the opposite side does the same thing automatically so both sides of the yoke engage with their magnets simultaneously. This minimizes any "racking" from sideways pressure when you are portaging.





Haven't been able to sit in the seat yet. The backrest might be a bit high. May need to cut an inch or two off of the vertical tubes to adjust.

Conversion from backrest to yoke position takes <10 seconds.
Placement of the yoke is unaffected by movement of the seat (seat can be put in two positions).



Some hints as to what's inside the yoke tube:



It would be great now if that lake would just thaw out...


Oh yeah, final weight:

[Moonman]

Hey Randy it looks great!

One question - how did you attach the hinge points for the yoke/backrest to the rear cross pce on the seat? Any special type of hinge? Also, what was your hull weight before any glass/epoxy/trim?

Great varnish job by the way.

Moonman.

[Patricks Dad]

The hinge for the yoke/backrest was provided by John Goodman at Cush Gear.

http://www.cushgear.com/index.html

Here's a photo of his hinge (as viewed from the bottom) from his website:

John has a very nice backrest (backsaver) product available for a couple different canoe seat designs (I bought one for another canoe I own). I contacted him to discuss my ideas for a yoke/backrest and he and I exchanged a few emails on the subject. He was kind enough to send me a couple of his hinges (in annodized black). Instead of the the aluminum piece between the hinge and the curved shape of the seat frame, I milled a couple pieces of cherry to do the same thing.

As for the weight of the hull itself, I collected the following info as I went along using a fairly accurate scale. I was unable to measure the bare hull (without glass/epoxy on the outside but I estimate it to be about 21 pounds):

[Moonman]

Hi Randy,

Thanks for the weight listing.

Big coincidence - I was actually on the cushgear site this morning as I think I might build myself a backrest for use on my tandem this spring.

I'll be very interested to hear how the boat handles once you get a chance to put it in the water.

Moonman.

[willo]

Very nice work Randy , love the photos. I want to build that design , looks nice. To bad about the ice , but soon. We still have over 2ft. of solid ice on lakes around here, but the paddle is already to go.