Games with Frames

[Chip]

This is a (rather sketchy) play frame for the Cutthroat tubes. I used some weird double-curve tubing for the inside rails (industrial hog-shelter parts). The floor is a half-panel of PolyMax kennel floor. The front edge is reinforced with aluminum channel, pop-riveted underneath, and supported in the middle with a loop of webbing (twisted so it won't present a foot snare). The seatboard and footbar are covered with a peel-and-stick 3M nonskid that comes in a 4" width. (The gray stuff is just as sticky, but less abrasive than the black sort.)


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Main differences from the previous frame: 1) the corners are pieces of 1" conduit, drilled and set with 1/4 machine screws and acorn nuts (to cover the sharp threads). 2) The seatboard is a structural element, held with U-bolts (also capped with acorn nuts). 3) The oarstands are welded "rainbow" type, drilled and bolted in place (i.e. not adjustable lengthwise except by drilling more holes). They're also heavier than the NRS model.


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3) The rear drop uses 2 heavy-duty plastic conduit ells with top-rail pop-riveted in the middle. Don't use plastic for key parts of the structure. The only function of this piece is to keep the tubes apart and hold straps from the inside d-rings.


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This shows a SpeedRail 1" IPS aluminum joint and 1" conduit 90° corner, pinned with 1/4" machine screws and two different types of nut. Brass acorn nuts are pricey, so I mostly use regular plated ones. The other nut is a self-locking type. The important thing is that the sharp threaded ends of the bolts are covered. It's also good practice to smooth the cut ends of tubing (wear gloves) until there's no possibility of slicing flesh or a tube. Both tubing cutters and hacksaws leave vicious edges. Another thing to watch is having the set-screws in the SpeedRail joints facing a tube. In that case, I wrap the joint with the non-sticky Vet Wrap, used for horses' legs and available in feed stores and pet supplies.


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This shows the underside of the floor, with the aluminum channel pop-riveted to the PolyMax grid and scalloped to fit over the frame tubing. I size the hose clamp to minimize the amount of "tail" and cover up the sharp edges with heat-shrink tubing.

[Chip]

This boat, called Kura (Maori for red feather) is the first frame I built, for Jack's Flyer Cat tubes (19" dia. x 15 ft. long). For tight, rocky water, I wanted a narrow rig with a low center of gravity, and this has been the ticket. For materials, see the list in the first (pictureless) post.

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This one has welded double-rail corners from Sid's sports. The rear bay (covered by a deckboard) fits a 70 qt. cooler. The two side decks (for dog comfort) are PolyMax kennel floor.


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The 90° drops are 1" nominal steel conduit with sections of chainlink toprail braised on to fit the Speedrail joint (at the top). At bottom, they're bolted inside the lower frame tubes with 1/4" machine screws and acorn nuts. The floor is a 2' x 4' PolyMax panel framed in wood, with aluminum bar and channel reinforcement. Relatively light, but rigid. And you can pee through it.


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The wood components add stiffness to the frame. The oarstands are bolted onto mahogany plywood recycled from old cabinets, while the seatboard is solid mahogany doused with epoxy resin. The board has a nice flex and the seat is a steel-framed type from NRS. The wood parts are fastened with u-bolts and acorn nuts (always cap the end of a bolt—an exposed thread will slice you open like a razor blade).


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Kura, on Deso in 2005, with an extra gearframe up front. One advantage to this sort of frame is adaptability. It can be set up differently for every trip, with the rower front, rear, or center. For added cargo, I built simple frames of top-rail with bolted conduit corners (no drops) to fit York Packs. Two York Packs drop in, with 3 gal. jerrycans on either side. Cooler in the rear, with a pad for seating

That's it for me. Your turn, amigos. Invent, or die.

[DanOrion]

Really Cool! Cleary lots of time and thought invested in these projects.

[Chip]

Haven't weighed 'em, but I can carry all three frames by myself without mashing a disc. The small red cat with either frame is an easy load on a roof-rack. solo, no sweat. And two average people can load the largest boat on a trailer.

The NRS or DRE cat frames are aluminum— lighter than steel— but they use larger diameter tubing with thicker walls, and bigger joints. So I think the weight ends up pretty even for a frame of equal dimensions.

No reason you couldn't apply the same methods & materials to a raft frame. The rub & poke potential bears watching, but on the other hand you don't need to build drops or floor support. And there's a lot less twist & torque than there is with cat tubes. Simpler, I'd think.

Jack (Paco) of Jack's Plastic Welding, makes tubes to whatever odd specs I devise. So that leaves frames. It's pretty labor-intensive, so I'm not tempted to build frames for the market.

But it pleases my soul to run some thundering drop on a frame I built. (And then to go home and improve it.)

kia kaha,
Chip

[Andy H.]

Sweet!

Thanks for sharing with us. I appreciate the effort you went through for your writeup - you should make sure to save a copy of it on your PC in case you need all the info later.

--Andy

[jahmon77]

i would also be interested.....

[jahmon77]

awesome frames......