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JNewman

Could a sheet metal power hammer be used to make this?

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This is a stainless steel ladle I have had to make 4 of twice now. They are 1/8" thick 304 stainless. The first time I made a round top die for my small power hammer and tried hammering the steel cold with a flat bottom die. When that did not work I tried a dished bottom die. I did get it raised a fair amount but couldn't get the edge shrunk enough. I also beat the hell out of my hands and never got one finished this way. I know the sheet metal hammers hit WAY faster but not as hard and you can hold part of the work under the bottom anvil. So I was wondering if this would be a job that a sheet metal hammer would do well or is the 1/8" stainless too heavy.

What I eventually did to make them is make a solid steel plug that forms the inside. I then have a heavy steel ring that is the diameter of the finished bowl that mounts elevated on my bottom die on the Massey. I get the disk hot sink it about half way then work the wrinkles out on the anvil then reheat and repeat. If I get it centered right off the bat I can do one in about 3-4 heats. If it gets off center it can take about 7-8.

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Here is a picture of two rejects and a picture of the finished ladles. The customer drawing called for a 13" disk You can see that was way too big. I ended up with a disk that is 10.5" which allows me to grind the top edge a little to clean it up. If I had a plasma cutter I would probably go with a slightly larger disk and would trim it off when I was done. That way being centered would not be quite as important.

I will have to figure out how to attach the pictures at home tonight, they are being rejected

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I think 1/8" stainless is too much to ask of a sheet metal hammer. Forging hot is the way to go- ball punch of requisite size over a ring of the requisite size, go slow and leave a big overlap to avoid wrinkles.
But you must also be able to buy these from somewhere.

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You probably can do that with a 20 ton hydraulic press. Speed is not necessary so a frame and jack might do the trick. You say you already have dies, so it would be a cheap experiment. You might be able to cheat heat the blank with a rosebud, with the edge clamped by another ring.

Phil

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When you get wrinkles this helps- heat the top and sides of the wrinkle but keep the bottom of the adjacent wrinkles cold (or chill them back down), that locks them in place while you beat the hot metal down into itself (upset). It really makes taking wrinkles out much easier.

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I would contact Renato Muskovic in Surrey BC. he makes very high end sheet metal power hammers and could tell you the pros and cons of the process. PM me if you would like his contact information. http://www.faybutler.com/yoder.htm

Could these be spun? I believe there are people here that have expertise in this area. I have made bowls from 3/16 stainless, although larger,l with a CN900 stationary nibbler (like a Pulmax P9).

brad

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I have them down pretty well now with my current setup. They don't seem to come up very often so I am not going to change my tooling unless I could cut my time significantly. A press might be better than the hammer but my vertical press is not big enough I may try my new horizontal but it would need a bunch of work on the tooling. The hammer sinks it in 2 or 3 blows.

I was just curious as to whether the sheet metal hammer would do it. I would just like to know what they are capable of.. I watched Renato Muskovic demo a sheet metal hammer at Caniron VI and it curved the metal very quickly.

A piece of steel with this much surface hot throws a lot of radiant heat but unfortunately it also cools down very quickly.

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<p>

. I will have to figure out how to attach the pictures at home tonight, they are being rejected
....................I found that if I email my pics to myself and them save them in ''my documents'' the files get down to -50k and can be uploaded to ifi.............usually.......cookieteaseplz.gif

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I would contact Renato Muskovic in Surrey BC. he makes very high end sheet metal power hammers and could tell you the pros and cons of the process. PM me if you would like his contact information. http://www.faybutler.com/yoder.htm Could these be spun? I believe there are people here that have expertise in this area. I have made bowls from 3/16 stainless, although larger,l with a CN900 stationary nibbler (like a Pulmax P9). brad


Funny I was looking up Renato's name and typing up my message while you were posting. Maybe I should contact him. I have wondered if it could be spun. and if so what it cost to spin it. Now that I have the tooling made up I can make them fairly quickly, so I made money on them this time. Last time I had hoped to do them with just the hammer and round die and then spent a lot of time trying that and then had to spend the time making the tooling so I did not do so well. If a similar job comes up in the future I would like to be more familiar with the other options. I might then sub out that part or if there is not another way to do it I can charge a premium.

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would a larger pullmax not be the tool for this? with a ring and ball tooling set up.

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would a larger pullmax not be the tool for this? with a ring and ball tooling set up.


I would love to know if it could do it.

I used to have a flypress and it could have done a shallow bowl and I dd some shallow bowls on mine. The frame interferes with being able to bend the sides up 90 degrees. The type with a removable pin for the bottom would do it but I have yet to see one in North America. As well I think it would need to be done hot.

Grant how would they let the zinc out if they didn't leak.

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would a larger pullmax not be the tool for this? with a ring and ball tooling set up.


I've got a big Trumpf nibbler, and I've done similar things on it, but only up to 1.6mm. I can do up to 3mm with my machine but my experience is that you need to shrink the edges some time during the process or you get the wrinkles. If you make it oversize maybe you can cut of the wrinkles, but I haven't explored that far yet.

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Could these be spun? I believe there are people here that have expertise in this area. brad


They could be spun. They would have to be "hot spun" on a steel mandrel.

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They could be spun. They would have to be "hot spun" on a steel mandrel.


Good, that doesn't sound cheap.

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I've never done it. At some point I hope to. Biggest cost would be the mandrel.
Here's the idea-

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I have a Eckold 665 Kraftformer that will shrink up to .250 steel plate cold.
Will do .125" stainless no problem.
It will work harden pretty fast so you need to anneal it so it doesn't kill the dies.

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I've got a big Trumpf nibbler,


I also have a Trumpf, a CN900. I had a Pulmax but I like the Trumpf more. Which model do you have ?

brad

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I have a similar project approaching where I will be making 80 shallow bowls 6" in diameter centered in an 8" square of 1/16" 304 stainless. The ideas here have me well on my way. What a great forum. Thanks to all for the input.

Tommy

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