This week we're looking for help. We are trying to form the top round over the rear fin on our bellytank. We thought the best way to do this would be to make a hammerform out of wood, and bend and hammer the aluminum over that form. Heres a picture of the form we built: That part of the project went well, and we thought we were on our way. When we tried to form the aluminum over the hammerform, frustration set in right away. We are using 065 aluminum, and it just will not form to the wooden buck. First we used straps and a body hammer: Failing at that we used the pneumatic hammer off my planishing hammer: Finally we went to the english wheel: After a couple hours, this is as close as we could get the aluminum to the shape of the form. So, we're asking all you metalformers,, How the hell is this done ?, and what are we doing wrong?
try to find someone with a sliproll that big? the other thing i might try is making the buck reversed from what you did,and pound it into the buck, good luck.
can you lay paper over your wooden part and not have any wrinkles? if so this looks to be a part with no shaping involved....the english wheel will stretch the metal so thats not the way to go.... i think if i was making this part i would have clamped angle onto the sides to keep them straight....then find a tall pole maybe 4" diameter (i use the ones in my basement) then gradually working side to side against the pole...bend the metal into an arc....get it to match the front (big) end of your wooden buck then find a smaller pole or object that matches a bit closer, but smaller then your other end...hold only at this end of your part and bend it around the smaller pole should put the gradual change in like you want.... im not sure if im explaining this right or not....but i think this is more of a freeform shape then needing to be formed or shaped over a buck i could be completely wrong though if the paper doesnt lay over nicely??? good luck Zach
It seems you have less surface area as the buck turns into more of a "fin" shape. You need to shrink the metal in this area OR you need to start at the fin and stretch as you move forward on the buck away from the fin. Maybe try laying some paper over the buck and see where things tend to fold and crinkle. I'm no pro, but have been reading a lot about metalshaping lately since I'm in the process of forming some panels right now too. You may even want to form these in two halves. You can always weld panels together. Smaller pieces are going to be easier to work with too. Or... maybe I'm a complete idiot and this is really simple... HAHA! Again, I'm no pro though. Just thinking along with you.
Probably a stupid question but .... did you anneal the aluminum? If not that will make all the difference in the world.
Chaz, You can find some help on the "Metalmeet Forum". There is a section on scratch built car bodies where you can post your questions. Track down Kerry Pinkerton of north Alabama who is building a '30s style Bugatti roadster body. N B R
Get a roll of paper and then wrap it on your buck - if it wrinkles up here and there then you know THAT'S where you need Shrinking. If it needs to TEAR to get it to fit than THAT'S where you need to do your Stretching. The paper being flat is a perfect road map to tell you the not so obvious places where you need to do your stretching and shrinking. If the paper rolls in place with no tearing or wrinkling then you know that the part needs only to be FORMED as opposed to SHAPED. The ewheel will do JUST FINE for stretching (thinning the material) heck some guys even shrink with their's (although I have never figured that part out yet). The Ewheel will also do just fine for FORMING your part - go get a car tire inner tube and slice off a piece as wide as your upper roller. Slip it over the upper wheel - it will offer enough complicance to allow you to BEND (aka ROLL) the metal as opposed to stretching it. The Ewheels equivalent to "off dolly" hammering. The idea of trying to force it to be compliant via the straps is a bad one IMHO, but I suppose you've already figured that one out on your own. Just for the record - (I hope I don't have this backwards) the difference between SHAPING metal versus FORMING metal is that when you form something you are effectively NOT changing the surface area of the material. An example of this would be a simple bend - done on your bend brake or similar. The basic operation of folding the metal does not change it's area. OTOH when you SHAPE the metal you are changing the area of the metal. And example of this would be to think of you metal like a ballon - when you hammer on it enough to make it thinner - it is the equivalent of blowing up your ballon. The ballon got bigger - the area got bigger - the metal got thinner. The reverse is true for shrinking as well- although the ballon anaolgy sorta falls flat (yes pun intended). Bottom line you FIRST need to determine what operation you need - definitions of terms are offered only as a way to ensure we are all on the same page - so to speak. Once you determine whether you need to shape the metal or form it - you will be WELL on your way. Good luck. FWIW - I'd do the majority of that part on an Ewheel........
Maybe I'm not seeing things right, but I would make that in 3 pieces. A top and two sides, then you can use you english wheel. That aluminum shouldn't be that stiff either. Should be able to form a lot of that by hand.
Put a rubber tire or inner tube on your e-wheel. Turns your e-wheel into a sort of slip roll. It will get you where you want, quick! I would make it out of one peice, not anneal it (no need, not that much shape in it). That is as long as your highest crown die will "fit into" the shape of what I beleive to be the rear section of your panel. I make tranny tunnels all the time with this method. No offense, but I have used one of those chinese wheels like yours, you might have to get a real one, those dont really work to well. Again, just trying to be helpfull. Just roll the part until it fits your buck. Use your buck to test fit, not to shape your part.
First question, is the top of your part flat with no shape front to rear? Lay a straight edge on top and see. If it is, it will be all form and no shape. If not, the best way is a paper or flexible shape pattern. A flex pattern is the best, because it wont lie to you like a paper pattern can. On this part, it looks like you can get away with a quick paper pattern. Goe to the Metal Meet site and all the info you can imagine on flex patterns is there. Dont cut your part out until you have all of it formed. You can use the excess for leverage when you bend up your part. You can clamp the appropriate size tube or pipe to a table and bend it up with a board a little at a time, until you get what you want. The english wheel you have with a rubberband around the top wheel will also do a great job. There are a few ways to do this! Also, the part does not have enough shape in it to need annealing. Tim @ www.irrationalmetalworks.com
http://www.metalshapers.org/tips/covell/annealing.shtml You need to over bend the part, so it will spring back to the shape you want.
There is little to no crown in that part. Annealing it will just create alot more work for you. Why make the metal all wavy and soft to make a straight part? Just because you are using aluminum does not mean the first step is to anneal it. A gas tank, or a 40 ford fender, "I.E. high crown part", sure. If you are making a box out of aluminum, would you anneal that first? No. Bending it around a pipe clamped or welded to a table will work to. Basically weld or clamp a pipe a little more than than the material thickness from a welding table, slide your piece under it and start bending up with wood (the length of the panel, to keep you from getting uneven bends down the side.) as Tim @ Irrational said. In my opinion you will probably end up with a choppy part, like alot of soft radiused brakes, but it will work. Using a rubber wheel will work better, quicker, and give you a nice natural looking shape. I bet you will be amazed!
Use some xxxx-0 stock shape it then heat treat it. Even once you first stage it to "W" you can still tweak it tell you age it to temper. Dont know how many times I have seen people trying to work T6 or T7 to a form and end up cracking it or it just springing back.
I think that he should start over using 3003 H14. 2024-T6 is very tough material. You could try to anneal it, but you probably got all of the shape you are going to get. If you are going to make the part in one piece, you'll need to do a lot of shrinking to get your shape. Like was mentioned, make a paper pattern to find where you need to shrink. A flexible shape pattern probably won't give you any useful information that you wouldn't be able to get from a regular paper pattern. If you are going to make the part in several pieces and weld it together you'll be able to do most of it with little or no shrinking by just raising it on the wheel.
Hey guys. The aluminum is 3003 H 14. It was not annealed however. I'll try that and give the rubber covered english wheel a try as well. Thanks for the help.
After looking at the pictures again, is there a difference in profile from front to back? After hammering on the piece, did you planish it smooth? Is there a crown from front to back? I'm sending you a PM.
I doubt that you will have any trouble after you anneal the aluminum. You'll be amazed at the difference.
You could make it in a couple of smaller pieces and weld them together. My choice for the part would be to make a big box, put your pattern in it and make a mold of the pattern. Pull the pattern out, anneal the aluminum, and then screw it to the edges of the pattern. Make an open frame, and screw that to the top of the pattern, sandwiching the aluminum. then hammer the aluminum into the mold. It's much easier to stretch metal than it is to shrink it (though not always the most efficient method). Hammering the material INTO the mold should be all stretching, no shrinking. You may need to remove the metal from the mold periodically and re-anneal it. -Brad
Listen to METALMIKE in regards to the go kart wheel. Using a rubber wheel, rubberband, etc will make that English wheel into a very useful tool. I probably use it set up that way more than I do with regular wheel. It simply bends the metal without shrinking or stretching it. No crown put into your rolls. Probably would take all of 5 minutes. Has nothing to do with the metal as it can be done with 16 gauge if your wheel can take it. Most guys kill themselves with hammers and an hour of wheeling when it takes a simple trick to make easy rolls. English wheels can be frustrating at first. This helps make the panels you wan rather than letting the wheel form something else. By the way mark a centerline down your panel and then make parallel lines evry inch or so. You can even number them out from the centerline. What this does is gives an easy way to keep your panel symmetrical as you can keep track of where you wheeled. Good luck
I third that. Go-kart slick would have that piece made in no time atall. There's barely any actual shape to it that I see it's most all form. I've tried hammer-forming large pieces like that before and if you can't have both a negative and a positive to sandwich between you're beating your head against a wall really. To me hammer-forming is most useful with smaller parts. I would like to add that if you turn out a narrow lower wheel out of wood you'll be able to get into the tight end of that. Like a 1x3" with the crown you want at the end. I say wood because if you use a go-kart slick upper wheel you don't need a steel lower. Wood ones are really super fast to make and function fine when using this method.
Before I get on the Go-kart slick, rubber band or rubber wheel band wagon like the last couple of posts suggested. I would want to know if there is any profile change from end to end. In other words, is the buck/form flat or straight. If it isn't flat, you will need to wheel some shape into it. The Go-kart slick won't put shape into it.
If the part calls for a subtle compound curve, do that part first, then rubber tire it. IMO you are gonna have trouble with that wheeling machine though, because it won't track straight, the anvils are not a true round shape, The bearings in the sides of the anvils are offset, the frame is too weak...etc. If you spin the top anvil, and run the lower one up to it until they barely touch, you will see how they skip. You can't put an even tracking pattern into the part. No even tracking = No smooth/even part.
If all you need is a simple roll... another way to roll the metal with the english wheel is to set the wheels so they barely pinch the metal, push the metal through in the direction of the roll, then pull it back towards you. As you pull back, put slight downward pressure on it, push back through without any downward pressure, pull back through with downward pressure... continue until you have done the whole panel. You will need to do multiple passes to roll the metal this way. Practice on some scrap first! It is easy to get creases in the metal if you don't support it correctly or if you pinch it too tightly between the wheels. I've done rocker panel patches this way, works like a charm. The go kart wheel method is easier though. John www.ghiaspecialties.com
The Jalopy Journal
