are there any good books/dvds on tube structures?

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I'm hoping to make exhibit type structures like this. Making one is not going to be that hard IMHO. Making two that are close to identical will be very hard. Seems like the bigger the curves and radius the harder it is to keep tolerances. Personally I do not think my customers will care that much if one unit is a few inches taller or shorter, but I do want as consistent a product as possible. I'm sure if someone buys a few units and tries to swap parts they will be irritated if they are slightly different. I see covell makes a dvd on tube bending, I've avoided their dvd's because they look very outdated, any reviews?
Reply:Repeatability isn't all that hard. Usually it comes down to a couple of key items.#1 quality tools. It's hard to make the same exact part 5 times if your tools have excessive slop. Cheap tools often have very poor tolerances and make doing exact repeatable bends tough without doing a bunch of mods. Fancy tools like Baliegh etc are usually easy to make consistent parts vs cheap tools where you constantly have to fiddle with things to get parts that are even close.#2 good jigs and fixtures. On the shed I just got done working on my helper couldn't understand why I spent almost an hour  building a jig to cut all the truss parts until he actually used it to make the parts. Then he realized it was a lot faster and more accurate to make the parts we needed, and he was able to make more parts later the exact same size when it turned out we needed more. As long as all the parts were cut the same size, when they went into the truss jig later, they all came out almost exactly the same. If something didn't fit, chances were a part was wrong or bent and it was quick and easy to pick up on before we were cursing later when something didn't fit right.#3 attention to detail. It's certainly possible to make exact repeatable  items without using expensive tools or jigs and fixtures. However you really need to pay strict attention to detail and make sure all the parts get made and adjusted to match. Lack of attention to detail will quickly wreak havoc even with the best tools and jigs. If all the parts aren't accurately cut or the person cutting or assembling the parts doesn't make sure they are fitting exactly the way they need to, you won't get consistent results.There's a reason why companies who need to crank out large volumes of repeatable parts spend a small fortune on specialized tooling and jigs/fixtures. 90+% of the time it's to reduce the amount of attention to detail needed by the average worker who lacks the skills and experience to do without. Even small shops often make use of these techniques. Yorkiepap has done several good threads on jigs and fixtures and if you look at some of Forhire's recent threads ( snow shoe thread comes to mind 1st), you'll note he goes thru a lot of "trouble' to make up specialized jigs so he can do a bunch of repeatable parts easily..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:thanks for the tips. the covell DVD sucked. I dont' recommend it at all. Basically you could visit tube machine manufacturer's web sites and watch their videos and all this DVD is a compliation of how to use the most basic settings on various bending machines. Perhaps that was usefull in the days before widespread video internet tutorials. , now it is obsolete.
Reply:basically what you asking for is nearly impossible to put into print.  you asking for a 3-5 year apprenticeship in print form.  Much of what you learn you learn from watching, doing, and reworking when screwed up.  rework is a great teacher.  You should be able to repeat the structure within 1/16th of an inch.  I have built structures that mate with other structures built by other welders and they have to fit.  all we were to go on were in the plans  many times calling for a +/- 3/32 which would give you and over al 1/16 play on your end and if they were to have the same tolerances then you would have little trouble assembling.  But sometimes you have 1/8th inch tolerance. These tolerances are met and superseded down to the thousandths everyday.  I love people.  You can tell when you have a tradesman vs a hack just by the care he takes to get it right.
Reply:Well I'm gonna be working on this project over the next week or so for a client. They will sell for around $2,000, probably should charge more, but my client understands this is a "get my foot in the door" type prototype. Obviously I'm not gonna take a 3-5 year apprenticeship, nor do I expect to have within 1/8" of an inch tolerance matching. within 1/2" would probably work/be acceptable. .....if that makes me a hack, so be it.....so here is my current plan:The hardest part for me is gonna be getting the very top edge that goes along the circumfurance of the shell repeatable. The circular curve will not be hard to repeat, but the Z-Axis off set I have not figgured out yet. I think I will get a floor jack and use that to change the flat circular pipe structure to a helix curve shape.if someone has a better idea/technique I'm all for it. I looked/searched for jig ideas for a 24' long circular helix , but suffice it to say, most jigs discussed on this forum are for totally different structures.
Reply:I can tell you right now +/- 1/2" ain't going to cut it if you want the parts to match up smoothly and evenly.I doubt that idea with a jack will work well.  So you jack the piece into shape. Now what? I'm assuming you will need to break this down into individual sections for transport. As soon as you relieve the pressure, the rolled piece will spring back, and that will happen with the 1st cut, leaving you basically at step 1 again. To get the thing to set, you'd need to over stretch the piece so it springs back where you want it. I don't honestly see this happening repeatably. Also in your 1st pict the start / stop points are not over each other, so what you actually have is a scroll where the radius is changing, not what you just drew.I'm sure someone who bends tube professionally could set up the machine to bend you you piece repeatably, or bend you repeatable segments that would get you to the same point. You'd need good shop drawings to tell them where the points need to be to work out the curves though.If I had to do this, my 1st though would be that I'd be tempted to layout the scroll on the floor and start off with the 1st piece on the bottom bent to match the layout. Then I'd work out all the heights in ascending order and make all the verticals. Then cut and bend the top to match the "studs". I'm betting if I got my buddy who's done cad work more recently than I have to draw it out on CAD, he could tell me the approximate bend and lengths I'd need,so I could do this. This would get me one though, and not be a production setup. Production wise, I'd want someone to bend up all my parts so they matched what the drawing showed, then probably tack them all up in a similar manner to how I'd do a single unit. My "jig" would help me locate and plumb all my verticals in two dimensions ( tops would be allowed to run wild to adjust for the changing height. I'd probably try and set the jig up so I could use it over and over to set each "pair" ( or however many) verticals if possible and progressively build the unit in place on the shop floor. If I did enough of these to warrant it, I'd be really tempted to make a plywood or sheet metal  "master" that matched the wall shape and locate all my verticals on the face of the wall. Then all I'd have to do is slap the pieces against the stops and clamp them and weld the parts in place. The number of pieces and how many times I'd have to do the job would determine how advanced I'd make the jig..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:I'm assuming you will need to break this down into individual sections for transport.Yes the 24' long scroll wil be cut into 8 equal segments 3' long each. if each segment is off 1/16th of an inch, I think it will still come together. 8x1/16" error is about 1/2" margin of error.  I'll find out soon enough. To get the thing to set, you'd need to over stretch the piece so it springs back where you want it. I don't honestly see this happening repeatably.That's pretty much what I was planning on doing, over stretching it. Repeatability between structures, like I mentioned before is not a deal breaker, though it would be nice. The main thing I want is an individual structure to come together easily. My client doesn't mind if one structure is 3" taller than the other. Also in your 1st pict the start / stop points are not over each other, so what you actually have is a scroll where the radius is changing, not what you just drew.Yes the scroll diamter is changing, 5.5' to begin with and about 8' at the end, I don't see this as a big issue. but when I bend my first piece I'll know for sure. Just need to bend a 8' dia. circle and then take and bend a section of it futher to 5.5'. At least in theory it should work. I'm sure someone who bends tube professionally could set up the machine to bend you you piece repeatably.Not much fun in having someone else make it!If I had to do this, my 1st though would be that I'd be tempted to layout the scroll on the floor and start off with the 1st piece on the bottom bent to match the layout. Then I'd work out all the heights in ascending order and make all the verticals. Then cut and bend the top to match the "studs".so you would cut up the 8 sections first and then bend them each individually? I was thinking of doing it opposite, Bend the 24' long tube first and then cut it up, that way the curve is for sure uniform. I'll let you know how it goes. The verticals will be made of telescoping tubing so they can be adjusted for best fit. "I'm betting if I got my buddy who's done cad work more recently than I have to draw it out on CAD, he could tell me the approximate bend and lengths I'd need,so I could do this. This would get me one though, and not be a production setup."Good idea, wish I knew CAD. All the tubing for one structure only costs $100 so it's not a big set back if I screw up a few pieces during the "invention" process. Production wise, I'd want someone to bend up all my parts so they matched what the drawing showed, then probably tack them all up in a similar manner to how I'd do a single unit. My "jig" would help me locate and plumb all my verticals in two dimensions ( tops would be allowed to run wild to adjust for the changing height. I'd probably try and set the jig up so I could use it over and over to set each "pair" ( or however many) verticals if possible and progressively build the unit in place on the shop floor. If I did enough of these to warrant it, I'd be really tempted to make a plywood or sheet metal "master" that matched the wall shape and locate all my verticals on the face of the wall. Then all I'd have to do is slap the pieces against the stops and clamp them and weld the parts in place. The number of pieces and how many times I'd have to do the job would determine how advanced I'd make the jig.Well hopefully I'll get a lot of orders, I dont' quite follow the jig description you've made, but after I make my first one I'll report back.
Reply:Originally Posted by AluminumWelderNot much fun in having someone else make it!
Reply:I agree overall, and farm some stuff out.... but I've already gotten quotes ranging from $2400 to $5000 to make the entire thing outright and none of them were interested in doing piece meal parts. It looks to be one of those specialties where it actually IS cheaper to do it yourself, but I'm am listening if anyone can give me company names that can do this bending for under a grand.edited to add, found this company and their jig to do exactly what I want. Looks like their machine uses offset rollers to create the Helical bend. My workshop is a bit too small for that contraption of a jig!Last edited by AluminumWelder; 02-05-2013 at 04:44 PM.
Reply:try nomma.org.  They have dvd on sprial stairs.  I don't have that one, however I do have other videos and are quite informative.  If anybody has it, does it address a manual way to form a helix?by the way there are companies that will do just the bending.Last edited by tapwelder; 02-14-2013 at 10:02 AM.
Reply:Originally Posted by AluminumWelderIt looks to be one of those specialties where it actually IS cheaper to do it yourself, but I'm am listening if anyone can give me company names that can do this bending for under a grand.
Reply:Not that hard to make with help from the board.Took around a 40 hours to plan and figure out. Should get that down to half the time now that we know what we are doing.Cost of materials is around $500. Used $170 harbor freight tube roller. Also invested in hydraulic tube expander, which will save a lot of time for future unit, from trying to do it manually with cheap $10 tool.size is 5.5x8'  Height is 7' 10" at tallest point and about 5' at lowest point.Set up for metal frame is 8 minutes with one person.....add maybe 5 more minutes to put fabric over it. If the fabric is just tossed in a bag it takes some time to figgure out what end is which. If it is carefully rolled up, it is a snap to drape over. Guestimate on weight is 45 pounds and approximately 2x1.5x4' when broken down. Fits into 4' long army duffle bag. Each broken down piece of pipe is no longer than 4 feet. The telescoping vertical collums let user adjust size by + or - half a foot. Like I thought there is enough play in this unit that having precise curves is really not a big issue. IMHO and I'm biased since I made it, this design is faster and easiser to set up than the 5 other companies designs I was quoted at considerably higher prices.This particular design only has a handfull of welds, in the next one all the vertical collums will probably be welded.Last edited by AluminumWelder; 02-25-2013 at 02:22 PM.
Reply:I've got a couple of more orders so I'm working on repeatability some more. I bought another harbor freight tubing roller and I will be welding two tube bending dies together to make a single die that bends two pieces of aluminum tubing at once, should hopefully make things exact!