Sheet Roller wanted

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I have a need to roll .080" 5052 aluminum in 4ft by 8ft sheets or 5ftX 10ft sheets. I would need a finished product anywhere from 18inch diameter to 30 inch diameter. Does anyone have plans so I could build one? Or have you seen an inexpensive one for sale? Sure, hydraulic is cool, but if it is cheaper, I can use Wheaties Power to get the job done. Ok, I know someone wants to know what the heck I need it for. I want to extend the pontoons on my boat and add a third pontoon in the middle at the rear.
Reply:For the width you are talking about I'm not sure inexpensive is possible.    I don't have experience building such a beast but I would imagine that you will need pretty stiff rolls for the 5 foot width you want to support.    This would lead to a correspondingly large support structure.   In other words a lot of steel to have to weld to gether and end up fairly precise.Have you considered having your local supplier bend the material?    Even a stiff charge might be cheaper the build it yourself route.    The big question in my mind is the roundness of the pontoons, they may very well have a none round profile.You could always build a temporary structure to bend the material.   But it woulds seem to be a lot of work to get a unit that would be functional and yet not a big invesment so that you can call it temporary.Dave
Reply:Dave is right- the minimum size roller you would need to roll a 4 foot wide piece of .80 aluminum is around 4" diameter. So your 3 rolls alone would weigh 42lbs a foot- 160 lbs each. Your framework to support this 450lbs of rolls, along with the gears to drive it, is gonna need to be at least 1 1/2" plate, 2" is better. This is too much to roll by hand. Friction alone, not even figuring in the force required to actually bend the 4 or 5 feet of aluminum, means you need a motor. The small, hand crank rolls, usually crap out at 20 ga or even thinner- the cheap Tennsmith hand roll, which is only 42" wide and costs a bit over a grand, is only rated for 24 ga.Jet makes a 16ga hand roll that MIGHT work on your aluminum- new cost is over $2500. But many of the sheet metal rolls will actually disengage their gears, and not work, when you try to crank them open too far, to fit thicker material in.I have a machine that does this- it is about the cheapest new 4ft rolls on the market, and it cost about 5 grand new. For a machine like that, THAT IS CHEAP. A real nice made in america model will run 12 to 15 grand. There are some used ones out there, for 3 to 5 grand, depends where you are and how lucky you are. Mine is a turkish made power roll from Cole Tuve- Its a 4' wide, by 12ga machine, which would do your 4' sheets just fine. 5' wide, thats a whole nother step up, in cost, size, and weight. http://www.coletuve.com/slip_rolls.html
Reply:Well, 5-10 grand is do-able because it offsets the cost of what I am making.  I would love to be able to go 10-20grand. But, my wife has seen me spend more freaking money in the past two months. I have to earn my money back on the tubing bender first. Hehehe.Thanks guys for the references. I will keep looking for a used one. Oh, and yes, today I went to my supplier and the guy that does the sheet rolling was off today. I will check in again on Monday. Let's say we bend two sheets, what would you expect to pay?
Reply:http://www.homier.com/detail.asp?Ses...cat=&sku=34034Try this it may fit your needs and it is very low priced
Reply:Joker11, I had a long comment drafted a few hours ago before dinner, then lost it with erroneous keystrokes.  Now I'm back and see that "5-10 grand is do-able..."??  Wow!  How much do these pontoons cost from the factory?  And here I was trying to help you do the job on the cheap.  Well, now that you got me thinking about it, I'll toss my ideas out there, anyway, for fun.  I'm a little intimidated to put these ideas out because it appears that you have some advice from pros in the sheet metal fabrication and machine design fields.  Also, it's been about 5 decades since I played with slip rolls in junior high school, and my college Machine Design books have been quietly composting in the basement for about 4+ decades.Anyway, two ideas:  1)     If you are still interested in building a slip roll for this special task, consider tubing for the rolls instead of solid bar stock rolls.2)     Possibly the task of fabricating the pontoon tubes can be accomplished without slip-rolling the sheets before welding?Regarding #1 above:  Judging from the numbers presented by Ries, 4" solid rolls would be adequate to roll 4', 0.08" sheets to 18" and 30" tubes.  What would be the required wall thickness of a larger diameter tube to get the same stiffness in a hollow tubular roll?The deflection at the mid point of a beam is inversely proportional to the moment of inertia (I) of the cross-section of the beam.  The moment of inertia of a solid circular cylinder (Is) is proportional to the fourth power of its radius, (Rs)^4.  The moment of inertia of a hollow circular cylinder or tube, (It), is proportional to (outer radius)^4 - (inner radius)^4, let's call them (Ro) and (Ri).  Thus, (It) is proportional to [(Ro)^4 - (Ri)^4].  To calculate the required wall thickness of a 6" tube to get the same stiffness as the solid 4" cylinder, we set (Is) equal to (It), or (Rs)^4 = (Ro)^4 - (Ri)^4.  Rearrainging, (Ri) = [(Ro)^4 - (Rs)^4]^(1/4),i.e., the inner radius of the tube as stiff as the solid bar is equal to the fourth root of the difference between the fourth powers of the tube outer radius and the solid bar radius.Running the numbers for a 4" solid bar and a 6" O.D. tube, I get a required tube inner radius of 2.84", giving a wall thickenss of 0.16", or somewhat less than 3/16".  The area of the solid 4" bar is 12.566 square inches and the area of the equally stiff 6" tube is 2.9355 square inches.  Thus, the weight of the 6" tube is only about 23% of that of the equally stiff 4" solid bar.Running the same calculations for a 6" tube with 3/16" wall thickness, the tube is about 27% of the weight of the solid bar while being 47% stiffer.So, the bottom line is that you can save about 75% of the weight OF THE ROLLS, ALONE, by using 6" tube instead of 4" bar.  (Check me on this, Ries.  I tend to make careless mistakes.)  I have no opinion of the relative cost of the bar and the tube or of the required thickness of the side plates.  If I was going to try to build a slip roll for this task, I would look into driving the rolls with the largest practical sprockets and heavy series roller-chain for easier fabrication and adjustment relative to gears, but I have no data at hand regarding tensile strength of roller chain or the required drive torque to roll your plates.Regarding #2 above:  Do you think it is possible to form the sheets into tube form and weld the seam without rolling the sheets into tubes first?  Consider this approach:Make a very rough mandrel with plywood disks or crossed braces and longitudinal 2 x 4s.  The purpose of this mandrel is merely to prevent inadvertent local yielding of the sheet while drawing it into a tube by supporting the walls from the inside.  Draw the sheet into a tube shape around the rough mandrel using many nylon webbing ratchet tie-downs from the auto supply store, tensioning all straps in small increments until you draw the edges together.  As you approach the full tubular shape, draw the mating edges into alignment using a 4" channel iron inside the seam and many segments of 2" channel iron outside the seam, drawing the open sides of the two sizes of channel together with a series of bolts passing through the channel webs and through notches in the edges of the sheet.  The notches would be welded closed after the tube seam was fully welded.  The 2" channel segments would have to have had notches in the clamping edge of the flanges to allow removal of the web straps before welding.  Reapply and tension the straps on top of the 2" channel segments to be sure the tensioned sheet doesn't get away from you except in the immediate proximity of the segment being welded.  I'd also use several safety chains around the whole assembly, just in case something gets away from you before welding is completed.  To maintain shape and keep things under control, remove and shift position of only one segment of 2" channel at a time, and retension each segment as it is repositioned.Skip weld the tube seam in several stages through windows previously cut in the web of the 2" channel segments, shifting the outer channel to access different sections of the seam for welding.  The outer channel can be in segments because the inner, 4" channel is the one maintaining straightness of the seam along the length of the tube.   The purpose of the two different sizes of channel is to apply bending moment to the meeting edges of the sheet to align them straight across the seam for welding.  The bulkheads required to maintain the round shape of the pontoons after seam welding is completed could be cut and formed with tabs at 90 degrees to the disks and the tabs plug welded to the tube walls.Crazy idea?  Maybe.  But it seems to me that it would be feasible with help from several friends and a keg of beer after the job is done.  I'd sure try it before spending 5 - 10 grand for a tool I had only a few jobs for.  You could try the procedure and learn the tricks on a 1 foot long section of tube.  If it works, just scale up the length of the mandrel and the sheets and the number of nylon straps.  If it is a bust, I hope you'd have had some fun at minor cost.awright
Reply:A lot depends on how many parts you are going to make, and if you are getting paid or not. I spent 5 grand on a roll because I use it all the time.  I bought it at least 5 years ago, and have used it on jobs that have brought large sums of money in. I plan on continuing to use it till I cant hobble out to the shop no more. So for me, its a good investment.I pay guys to roll sheet for me, that is, I have employees- so I need an idiot proof machine, not that my employees are idiots, they are not, but I dont want em fixing or fiddling, I want em rolling and moving on to making the next thing.When I said 4" rolls, I meant for a machine capable of 12ga or 14 ga steel. Now you MIGHT be able to roll the aluminum on a machine only rated at 16ga steel- if you only had a few to do, and money was scarce. But in production, its not gonna work very well, and the machine, particularly a funky chinese item like that Hornier- which I gotta say, I really doubt can do 16ga cold rolled- is gonna break. And no way are you going to be able to resist the temptation to run some thick steel thru it too- so its better to have a slightly oversized machine than and undersized one. The bigger the roll size, the smaller the minimum circle you can roll. So using big pipe to make rolls cuts down on how small a circle you can roll. For onesies or twosies, its certainly possible to roll aluminum around a mandrel- an old barrel, some scrap pipe, or a plywood form, using nylon straps to pull it tight.Me, I have a fab shop- I tend to think in terms of professional equipment producing repeatable results, which, of course, means heavy metal, big motors, and lotsa bucks. I realize not everybody thinks this way. I tend to really LIKE big machines, so when there is an excuse to buy one, and a job that needs it and will pay for it, I do. I find once I have a real tool, like a power roll capable of rolling 12 ga steel, I come up with other jobs for it, hopefully paying ones.So- if you only need one, or two, there are cheap ways to do it. If you are going into production, and trying to sell these for money, 3 to 5 grand for a powered roll is probably worth it. All depends on YOU, and your situation.
Reply:I kinda like arwright's #2 suggestion especially for a perosn doing a retro fit on his own boat.      Even then I suspect that the bending operation witll be a lot of work and I'd be concernend that care be taken due to spring back.    Wouldn't want to get slapped around by a sheet of aluminum.You seem to be a professional fabricator if so I can see why you would want to increase your stock of tools.    If you have the intention of doing a lot of work like this don't go to small on the machine.   As to the pontoons themselves are we talking about round tubes here or are we talking about U shapped pontoons?   The reason I ask is that if they where of the U shaped variety then I might be inclined to say making a big die might be in order.   That is bend the sheets in a press.    Of course the economics of this are probably not that good.ThanksDave
Reply:Truth be told....I don't want the slip roll for just my one project. That would just be the FIRST one I wanted to do. But I have an idea for manufacturing a product and my wife keeps telling me to make it and market it. I seem to always have these ideas and then a couple years down the road someone actually makes one and my wife kicks me. I used to run a mobile welding service and had just welding equipment, but now I am scooting over into fabrication and am slowly buying fab equipment. You would think that the two jobs might require the same tools, but so far....no. Most of my welding was repairs to existing structures or a quick production of items that could be made with minimal fabrication tools. When I say 5-10 grand is do-able, I don't mean that I just have cash laying around with nothing to do with it. Just see it as an investment in a tool that, again, in my area not a lot of people have. I could be rolling stuff for other smaller shops and be making my own money on the side with it. But the best part is that you guys came up with some ideas that I had considered, but wasn't too sure about. I actually thought of rolling the AL around a steel pipe with a desired OD and tacking it, then sliding it off and finishing the seam, ha, but what if the AL shrinks and is now snug as a bug around the pipe? Oh and they would be round, not U shaped.  Hey, I got what I wanted here, a bunch of good answers. Thanks alot guys. The best part is that my investment in education of vocational skills has been paying back.
Reply:Originally Posted by Joker11I have a need to roll .080" 5052 aluminum in 4ft by 8ft sheets or 5ftX 10ft sheets. I would need a finished product anywhere from 18inch diameter to 30 inch diameter. Does anyone have plans so I could build one? Or have you seen an inexpensive one for sale? Sure, hydraulic is cool, but if it is cheaper, I can use Wheaties Power to get the job done. Ok, I know someone wants to know what the heck I need it for. I want to extend the pontoons on my boat and add a third pontoon in the middle at the rear.
Reply:Yeah, that would be ok for the third one in the middle, but the other two are already round....so I have to match the diameter and shape for it to work. But that is a pretty good idea if I build a completely new set. Which, by the price of aluminim....wow. Not sure I want to start there. GREAT IDEA though! Do you have pics of those boats?????
Reply:I lost a lot of pictures in my last divorce and that was over 20 years ago.  The  shortest pair were six feet long and the longest  about eight feet.  Very light.  The front looked like a transition.