Portaledge designs
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I'm a fan of working with metals and fabrics, I've made many a weather vane and backpack in my time. |
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I've been doing some research to do the same thing. Found a few useful pages out there. Hope this helps. |
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i'd go with titanium tubing to shave weight, otherwise your probably better off buying a ledge off ebay and re-doing the bed. there is also info on rc.com about the krusty ledge made from PVC and a home made bed. |
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Thanks for the links Greg! |
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Titanium is awsome due to durability and weight, really expensive...Looking @ around between $20-$30 a foot. A decent sized single is uses around 20'. If you can find it @ a good price it is worth it. |
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I know it's more expensive... not sure how much. But 7075-T6 aluminum is much stronger 6061-T6. 503MPa yield strength vs 276MPa. It's a bit stiffer too. Might help you with your design sans the spreader bar. |
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Luke Malatesta wrote:Titanium is awsome due to durability and weight, really expensive...Looking @ around between $20-$30 a foot. A decent sized single is uses around 20'. If you can find it @ a good price it is worth it. Here are some pics of a few I made in my shop @ my house. Love this topic! All have titanium frames- 2024 and 6061-t6 corners...Working on a Carbon fiber one that breaks in thirds. Bed is Ripstop dyneema fabric. All aluminum hardware. Around 7 lbs Not to hard to make once you get the pattern...Let me know if you have any questions. LukeWhere did you source your fabric & tubing from. I'd be interested in the actual frame structure, tubing size etc... Also you using a home machine for the sewing or an industrial? T |
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Yeah Luke, I'm also really interested! |
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Larry, |
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luke, |
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Cheer Luke, that's all great advice! |
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Luke, |
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Greg, |
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No worries Luke, I've searched the site and stumbled across some of your pictures. You can hijack all you like because I'll probably be borrowing from some of your AMAZING* designs.
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Luke, |
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No problem Greg....I think that the carbon fiber unidirectional tube will work great....Some of the best tube I have found comes out of Salt lake here in Utah. |
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I haven't thought about binding the edges, that's a good idea. I really just thought about folding and sewing the edges into a fold. I definitely can't afford a bartacker so I'll have to figure something out with a regular machine, luckily webbing is cheap so I can experiment. |
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Kindofa special design thought. |
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A few random thoughts from my attempts: Bartackers are not needed for the ledge body, just use linear tacks (back and forth). Early A5 and Fish stuff was done without tackers and was bomber. Tackers are HUGE time savers once you get to things like the ledge suspension, easily 5-10x faster. Consider begging Fish, or finding a local person who can tack for you for those bits (i.e. send it to them taped or pinned together). #69 thread works OK in home machines and is about their limit. You can still make a bomber ledge this way, but plan on triple stitching in spots where you see double stitching on commercial ledges. Watch craigslist, you can probably pick up a decent single stitch non-walking foot machine for $300-400 if you are patient. Good walking foot machines are worth it if you can swing it, but expect those to start in to the $700-800 range for anything in good shape. Invest in a reduce pulley or servo motor (or both) to get enough control for sewing of this nature (especially if you only sew occasionally and don't have mad skills). Occasional steals go by, so be ready to pounce on them, I got a computer controlled walking foot for $800 that sells for $4.5k new, and usually $2.5k+ used by shear dumb luck (and lots of patience). Carbon fiber and Titanium is insane as a material unless you get a deal. Big walling is insane too, so it makes perfect sense. My tubing for my next project is coming from Rock West Composites. $460 for a ledge worth of 1 1/8" carbon fiber tubing. Sadly the 72" standard lengths work out very poorly to break the sides into thirds, so I am just going to break them in half instead. Overall the CF tubing saves about 2 lbs compared to aluminum (22' of 0.23 lb/ft 6160 vs 0.13lb/ft carbon fiber). My current ledge has unequal pole lengths. Side poles are 39.5" and 42.5", end poles are 22.5" and 25.5". With a 6" joiner overlapping by 3" this makes the broken down length equal which makes it pack up pretty darn tidy (well as tidy as you get for a broken down monster ledge). I really like how this came out. I should not have put tensioners at both ends of my ledge. Because my ledge has end poles that break down I can use a simple continuous piece of bungy cord to hold it all together, and don't need the end poles to be free floating like BD's (and I assume Metolius?). The extra set of tensioners just mean more hassle, more sewing, more weight, and precludes using thick webbing as a rash guard on that end. Angle the fin more than you think you should. I only angles mine by 3" on each end, and should have done more like 6-8". Your feet need only about half the space your torso does. I am also considering doing a 2:1 for the fin tension straps. Fat guys like me make it hard to get the fin as snug as would be nice. Tubing can be gotten many places. I like aircraftspruce.com, and wicksaircraft.com for 4130 and 6160. If you chat with them they can cut tubing to your dimensions for a fair price. I only paid $5 cut charge at Aircraft Spruce to get 4 6160 joiners and 8 4130 tubes cut to size last time. Figure on $100 or so in tubing as a ballpark for a double ledge. 1"x0.035 4130 worked just fine on my double, but is heavy. A5 ledges use 1 1/18"x0.058" 6160-T6 with 0.083" thickness double butting and joiners. Consider using 1 1/8"x0.058" Al tube with 1"x0.047" 4130 joiners to reduce binding (or find a source for anodized tubing). If you hate binding as much as I do consider just taping the inside curves. For the long straight runs just fold the raw edge under. Pre-ironing the binding tape into a taco is a must if hand binding without an attachment (and is not bad for small projects). Practice on scraps... Expect the bed to stetch, my 1000d cordura bed one gained about an inch on the width after getting stretched out the first couple times. Aim to barely be able to assembly the ledge, and make the side poles just a little long. Once the stretch is in there decide if you want to shorten the poles a bit or not. Rough quantities (for cabana sized): 22' tubing ($70) 2' joiner tubing ($20) 2' double butting tubing if using 6160 ($20) 4 corners ($60+) 3.5 yards bed material and bin material ($30-60) 80' 1" thin flat webbing ($30) 6 metal cinch buckles ($12) 6-10 1" ladder lock plastic buckles ($5) 15-20' thick flat 2" webbing for the rash guards ($12) 1/4-1/2 yard ballistics for the end rash guards ($10) 6' 1.5" thin flat for backside fin reinforcement (unless sewing taco style like A5/BD) ($3) Binding tape Plan on $300-400 in just raw materials/shipping and a 2-3 weekends to knock out just the ledge. Size your ledge to match an existing fly, or develop mad sewing skills. Don't forget the ledge haulbag. In short, if you want a weekend hobby this is an awesome project. Otherwise you'll quickly figure out that Fish/BD/Metolius are not ripping you off as much as you think they are. Especially the Fish Econoledge is an absolute steal. |
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Got my machined corners in, and they turned out great. Hopefully I can finish my frame this weekend. I have enough corners for 7 ledges, and I'm thinking to selling off 4 sets (PM me if interested, $125 shipped for a set of 4). |
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Beautiful! |