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Comment by fiter | Hacker News Reader

I figured they would be using a brake[0] for the bends.

[0] https://en.wikipedia.org/wiki/Brake_(sheet_metal_bending)

That's a lot slower than stamping from sheet and has all kinds of limitations with respect to angles and manufacturability. I've used them a lot making sheetmetal enclosures for industrial hardware, it's great for simple stuff, right angles and other common shapes but if you start doing sheets that have multiple bends at precise angles at odd angles to each other you'll run into the geometric limitations very quickly. Keep in mind that the wedges need to cover all of the angle for the brake to work and that you need to be able to remove your work without disassembling the tool.

This is a more likely option:

https://www.247tailorsteel.com/en/plate-bending

These machines will do full sized sheets as well and are much more versatile than a brake, also far faster.

I believe that is a type of brake, a press brake.

Ah ok, I do not know the name for that particular tool but I've seen them in use for sheetmetal bending in large quantities.

The device the OP linked to is meant to be hand operated and only for small series. Setup takes forever and then some, redoing a setup for another batch is impossible because it will all come out slightly different.

That 'press brake' uses a tool-and-die style mechanism to deform the sheet, very accurate and highly repeatable, quick as well, cycle time is a few seconds.

yeah but that doesn't make really sharp angles and controlling the curve where it bends precisely is hard, fighting that is going against the claim it's about manufacturing efficiency

Point well taken.

There are multiple dimensions to manufacturing efficiency, though, right? I have no appreciation for the cost of a couple dies and a machine for stamping versus the cost of a CNC break with one die, but it may play a part based on the number of units they think they will sell. (1,000? 10,000? 100,000?)

If starting with super hard cold rolled steel, it’s most likely impossible to “stamp” using traditional progressive stamping dies. The deformation has to exceed the final shape and via springback the final shape is produced.

Springback is possible on a press brake when folding along a single straight line. If panel needs a 30 deg bend, then bend it to 40, and it pops back 10 when off the press brake. As an example.

That quickly gets impossible to do when you start bending around complicated 3D contours.

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