.png)
Tweet
As some of you may remember, I picked up a tiny iron worker on the cheap several months ago. The punch station was missing the punch retaining nut, stripper, and punches / dies. It did come with the coping attachment but no angle iron shear. The coping notcher was severely damaged and I will need to buy new blades for it and replace the pivot. Instead, I decided on a different strategy:
1) Build a notcher to work in the punch station. This notching attachment would be able to take bites out of angle iron, similar to this: https://www.trick-tools.com/Rectangl...4aAi_pEALw_wcB. My notcher will be built using material I already have on hand, including a bar of 1" by 2.5" O-1 tool steel. However, it's only a 35 ton unit so I've decided to make the notcher 1" wide by 3.25" long. Unfortunately, this means I will likely need to take 1-3 bites to notch the sizes of angle iron I use most often (2" to 3"). But I think that is still preferable to notching with an angle grinder.
2) Build an angle iron shear to take the place of the coping attachment. It's not often I find myself notching to bend an angle iron frame. More often, I need to cut lengths of angle iron and then notch various locations along the length to weld in cross members. Ideally, I'd have all three - coper, notcher, and shear. But I don't think I can pull that off on this little machine. Best I can do is a small notcher and an angle shear with the ability to remove the shear and replace it with the coper if the need arises.
Iron worker as purchased (it has since been repainted and tuned up):
So... here's my late night attempt at a notcher design. I'm sure it's not an optimal design but the main constraint is using material I already have on hand. I'm trying to make this without spending any money on new material. But I do have concerns, perhaps greatest of which is the clearance on the top blade. I initially tilted the blade down by 2 degrees to provide some shearing action (reasoning that it would make it somewhat easier on the machine than having to punch straight down) and the negative tilt meant that it would grab at the root of the angle iron and try to suck it in slightly. To get clearance for the nose of the top blade, though, I had to angle the bottom blade and that meant that it wouldn't be fully symmetrical, reducing the number of cutting edges.
I then decided to tilt the top blade to a positive angle of 1 degree. Now the nose has clearance while all blades are fully symmetric. But it means it will try to push the angle out as it shear... at 1 degree I don't think this will be an issue but then, at 1 degree, is it really doing any good? Should I just keep it straight? All of the bottom blades are designed to be adjusted with shims to maintain clearance all the way around.
Also, replacing any of the blades requires some disassembly / order-of-operations care. It's not the most elegant design but I guess blades won't have to be replaced very often with the kind of volume I do.
An amusing anecdote you can probably relate to: I've bought several old machine tools that need to be rescraped. Some of them have fairly long bearing surfaces so I bought a used straightedge to fix the machine tools. But the straightedge needs to be scraped before I can use it so I bought a larger surface plate at auction. Unfortunately, this plate was not on a proper stand and was sitting on a very unstable cart. So before I spend the money to have it lapped and calibrated, I want to make a proper stand for it out of angle iron. I bought the iron worker to help speed up fabrication projects using angle iron and strap. But first I need to build the shear and notcher for it and I need to sharpen the existing flat shear. So I bought a surface grinder and a heat treat oven. But the heat treat oven doesn't work so I need to build a new controller so I can heat treat the blades for my ironworker so I can build the stand for my surface plate so I can scrape in the straightedge so I can fix my machine tools. And now I'm thinking about buying an autocollimator so I can check and maybe even lap my own plates <sigh>
1) Build a notcher to work in the punch station. This notching attachment would be able to take bites out of angle iron, similar to this: https://www.trick-tools.com/Rectangl...4aAi_pEALw_wcB. My notcher will be built using material I already have on hand, including a bar of 1" by 2.5" O-1 tool steel. However, it's only a 35 ton unit so I've decided to make the notcher 1" wide by 3.25" long. Unfortunately, this means I will likely need to take 1-3 bites to notch the sizes of angle iron I use most often (2" to 3"). But I think that is still preferable to notching with an angle grinder.
2) Build an angle iron shear to take the place of the coping attachment. It's not often I find myself notching to bend an angle iron frame. More often, I need to cut lengths of angle iron and then notch various locations along the length to weld in cross members. Ideally, I'd have all three - coper, notcher, and shear. But I don't think I can pull that off on this little machine. Best I can do is a small notcher and an angle shear with the ability to remove the shear and replace it with the coper if the need arises.
Iron worker as purchased (it has since been repainted and tuned up):
So... here's my late night attempt at a notcher design. I'm sure it's not an optimal design but the main constraint is using material I already have on hand. I'm trying to make this without spending any money on new material. But I do have concerns, perhaps greatest of which is the clearance on the top blade. I initially tilted the blade down by 2 degrees to provide some shearing action (reasoning that it would make it somewhat easier on the machine than having to punch straight down) and the negative tilt meant that it would grab at the root of the angle iron and try to suck it in slightly. To get clearance for the nose of the top blade, though, I had to angle the bottom blade and that meant that it wouldn't be fully symmetrical, reducing the number of cutting edges.
I then decided to tilt the top blade to a positive angle of 1 degree. Now the nose has clearance while all blades are fully symmetric. But it means it will try to push the angle out as it shear... at 1 degree I don't think this will be an issue but then, at 1 degree, is it really doing any good? Should I just keep it straight? All of the bottom blades are designed to be adjusted with shims to maintain clearance all the way around.
Also, replacing any of the blades requires some disassembly / order-of-operations care. It's not the most elegant design but I guess blades won't have to be replaced very often with the kind of volume I do.
An amusing anecdote you can probably relate to: I've bought several old machine tools that need to be rescraped. Some of them have fairly long bearing surfaces so I bought a used straightedge to fix the machine tools. But the straightedge needs to be scraped before I can use it so I bought a larger surface plate at auction. Unfortunately, this plate was not on a proper stand and was sitting on a very unstable cart. So before I spend the money to have it lapped and calibrated, I want to make a proper stand for it out of angle iron. I bought the iron worker to help speed up fabrication projects using angle iron and strap. But first I need to build the shear and notcher for it and I need to sharpen the existing flat shear. So I bought a surface grinder and a heat treat oven. But the heat treat oven doesn't work so I need to build a new controller so I can heat treat the blades for my ironworker so I can build the stand for my surface plate so I can scrape in the straightedge so I can fix my machine tools. And now I'm thinking about buying an autocollimator so I can check and maybe even lap my own plates <sigh>
Comment