Thanks. That should certainly give long life but how to you plan to attach the lathe blank?

@@thebluecaddy2950 Not hard to attach at all. The back of the bottom die machined from 1018 to louver shape, the cutting edge held in a machined groove with 3/8 set screws and a tack weld on either end. The punch is machined again from 1018 and the cutting edge area machined out to the size of the square profile of the bar of HSS and welded in with MIG in short bursts so you can let it cool between spots. HHS welded to 1018 actually makes a pretty strong union. I have a glass pack coring machine I built 25 years ago that punches 6 louvers around the radius of a length of exhaust tube. I would surmise each of the sIx HHS blanks has punched 3 million louvers without sharpening having just done the math.

Thanks but I can't take any credit for the registration aspect. I just copied what I'd seen on other videos here.

Go for it!

I wasn't really planning to but will consider it. How many louvres (punches) do you need and what gauge steel?

Thank you!

The louvres are 5/16" high so I did a full radius running all around the back side. For the back corners - when looking down on them - I basically copied what I'd seen on others. I rounded it off until it looked right. I think there is a standard look to them and I just tried to achieve that. They are 3/4" front to back and spaced 1 1/4" apart. That is pretty standard and does look traditional.

Thanks! No video of the build. I can say from researching the fab process of these punches, the most critical thing is getting the shearing edges positioned accurately and very close to each other - .005" or less. This ensures that they will punch the Louvre when pressure is applied and there will be no binding. Basic building sequence was first build the basic parts with the dowel pins. Next, mount the female half of the cutting tool on the base. Then temporarily mount the male cutting edge inside the female and onto the base with machine screws. (You can see the holes in the video) I did it with a .003" shim between the two cutting edges. Then I slid the top section over the big dowels and drill two 1/8 ' holes for dowels through the male cutting edge. Take everything apart, unscrew the male cutting edge from the base and now attach it to the top section using the 1/8" dowel holes to accurately locate it. All other dimensions are not critical, I just used material I thought was strong enough. Top and bottom sections are 1" x 2" 6061 aluminum I got from McMaster Carr.

I used a 12 ton press. I don't think this method would work with much less than that.

The press in the video is 12 tons. It takes most of that to punch the metal.

Thanks. That would work but I wasn't planning to punch a great number of them.

Thank you!

Thank you. I actually arrived at these results faster than I thought I was going to. As I mentioned in the video, I learned a lot from watching similar videos here. I adjusted to the 6" louver I wanted. One tip I got and implemented was that it was critical that the cutting edges have only about .001" - .002 clearance between each other so I designed the tool to allow myself to be able to align them that accurately.