A large silver cone attached to a black hemisphere floats over a piece of sheet metal held in a metal frame. The metal has what appears to be machine grease on it to aid in the forming process.

CNC Metal Forming

Forming complex shapes in metal sheets is still a laborious process, especially if you aren’t needing more than a couple parts so stamping doesn’t make sense. That may change with Digital Sheet Forming.

While this video is basically an ad for one vendor’s approach, it gives a good set of examples of what the technique can achieve. The high pressure mechanism of the machine presses the metal layer by layer down against a silicone backing to form what you’ve designed, in this case, the nose cone for a Tucker Carioca.

Some people will decry it killing the metal forming industry, but as [Rob Ida] says in the video, it will allow metal formers to become more efficient at the work they do by taking out the tedium and letting them focus on the parts of the process requiring the most skill. Anyone who’s done any work with a 3D printer or CNC mill will know that sending a file to a machine is only one small part of the process.

We’re anxious to see this technology make its way to the makerspace and home shop. If you want to do some sheet metal forming now, why not try hydroforming?

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Metal Forming With A 3D Printer

How do you use a 3D printer to bend metal? One way would be to take it to a machine shop and offer to trade the owner your printer for some time in their shop. A smarter way is to do like [Jaba 3D], and print dies using the printer. You can then use those dies in a press to make the shapes you want.

In the case of [Jaba], the Harbor Freight press uses a hydraulic cylinder to develop about 6 tons of pressure. We don’t think Harbor Freight carries this particular press, but for between $150 and $250, you can get a 12-20 ton press, and, of course, there are other suppliers, as well.

The target object, in this case, was an automotive bracket. The process of grabbing an image, converting it to an SVG, and then creating a 3D part has many uses. Apparently, PLA is sufficient for this purpose, although the print uses ten top and bottom layers along with 80% infill. That does make the prints take a long time.

As you might expect, the dies don’t last very long. In this case, they needed two shots, and they got them, but PLA is probably not the right material if you wanted to go for mass production.

Metal forming does occur at large scales, too. If you want to make your own press-forming tools, we have advice for you.

men working on screw conveyor stem

Ingenious Indigenous Artful Screw Conveyor

Many of us have heard the name Archimedes’ screw — but not everyone knows the term screw conveyor.  These folks (sadly, the videographer at [Breeze Media] doesn’t tell us their names, or the company name) has the process of building screw conveyors down to a fine art.

Screw conveyors are useful, but many folks shy away from them because they look hard to make. In this video, we see how it’s done. The crew in this video are doing it in metal for large equipment, but the same methods could be used in plastic sheet or paper on a small scale.

It starts with cutting washers and slitting radially. When they’re distorted into the final shape the hole will close up, so the hole is a bit larger than the pipe that forms the center. They’re then given a slight spiral (think a lock washer) by walloping with a sledgehammer. It works. The slit edges are welded together to make a ‘compressed’ spiral, and the end is welded to the pipe

Now for the ingenious bit. They have a tall gantry, just a couple of pipe poles with a crossbar, set up in the factory yard. Below it, they’ve drilled a well. The free end of the pipe goes down the well. The bottom of the spiral is clamped to a baseplate around the well. Next, the pipe is hoisted up to form the final shape. Finally, everything is welded in place.

In the video after the break, they’re making a screw feeder. It needs a lower pitch for the section under the hopper. So they clamp several turns, pull the main section out, weld it, then move the clamp and make the feeder section.

Hacks are partially art, and screws are visually interesting. This piggy bank has one. Put one in your next hack!

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