Making a louvre die set

[Ron Naida]

Hi All,

A while back a member asked me how I made my louvre dies and used them.
The following was my reply. Pics are in my gallery.
Ron Naida









Making a louvre die set.

Bill the top die is a piece of rectangular bar stock with a slot milled in it to accept tool steel as a cutting edge, start by cutting that to length, Use the round over bit to give the louvre shape. Then screw in the cutting steel. Lastly grind the tool steel and polish the upper die assembly.

Bottom die is a "U" shape made of 1/2 inch square material. Drill and tap the ends to accept a half by half piece of tool steel bar. Once that is bolted to the front you have a front cutting edge on the bottom die for the top die to shear the metal as it comes down. I take lead and heat it molten in the bottom trough while it is liquid bring the top ram with die attached quickly down into the pool. It will spill over the sides, but let it cool good. When you raise up the upper die you have a matching female die. I never got fancy with clearances as far as shape to shape goes. The only clearances important are the upper flat shear surface to the square lower shear surface.after the dies are down and together.

I bring the top die down into the lower die until it almost bottoms, adjust the bottom die towards the cutting edge of the top. I leave almost no clearance. When you are adjusted put a mark on the ram so you don't bring it down too much when punching a louvre. What happens is if there is slop in your ram as the upper die comes down it wants to come forward and then it chips or breaks the half inch square cutting edge.But you are going to buy that material in 18" lengths so you have replacments Right?

If you have too much shear clearance it won't cut or the cut looks ratty. When I have mine adjusted good it comes down, the spring loaded pressure bar holds the metal. I line up my layout marks, press down further on the pedal, The flex is taken up in the press, there is a boom sound and the louvre is cut and shaped. It is not something I can watch by the thousandths as it comes down.

This is how my press works. I never bothered to worry about how and why it does its operation in any greater detail than I needed to know to fix a malfunction. Mine is a little primitive, but punched alot of nice louvres in the last 15 years. One thing i did do was put a bracket on the ram holder so a dial indicator mounted on the ram could tell you when the ram was at the same down position on all louvres. After once or twice I found a sharpie mark on the ram was good enough.

Sounds like I am rambling on but I thought i would throw out bits of info you could use.

Good luck,
Ron Naida

http://www.metalmeet.com/photopost/s...y.php?cat=3881

[Archie]

Ron

Thanks for sharing this. I was wondering how long the lead die holds up?

Archie

[Gene_Olson]

The lead die face is in the same position that lead and pitch are used in repoussé work. The metal is pushed against it by the tool and it deforms.

When molten. (VERY Soft) Ron cast the lead backing block in the shape of the upper punch.
The first time he used the punch, he put a piece of steel into it and pressed down. The lead acted like a very thick fluid and flowed to match and hydraulicly support the sheet steel surface above it as the punch came down.
It held the steel against the die surface and the lead flowed to match the combined surface of the tool plus the metal.
That is exactly what happens in any given blow with repoussé using pitch or lead. In his punch however, after the first louver, the metal is just stretched until it bottoms out and the lead provides that "hydraulic support " only for the last bit of the plunge.

Ron's gallery - the Louver Die Album -
http://www.metalmeet.com/photopost/s...y.php?cat=3881

I'm curious too Ron, have you had to recast the lower mating surface?.

the lead block doesn't seem to be surrounded by steel. it can move.

Have you used different quages of material in it? Did that make a difference?

Gene

[Gene Newcomb]

I keep some in my Ebay store. I use rubber sandwiched in the bottom. The sheet metal is going to take the shape of the top die come hell or high water. I would assume lead would last forever.
Gene

[Ron Naida]

Gene Olsen asks:

I'm curious too Ron, have you had to recast the lower mating surface?. --- No it lasts quite well.

The lead block doesn't seem to be surrounded by steel. it can move.--- The bottom die is a "U" shaped piece of 1/2" x 1/2' hot rolled that is drilled and tapped on it's underside. To it's front is fasted a piece of 1/2 x 1/2 tool steel. This assembly is secured to a 12" square plate 1/4" thick. I then pour the lead in the rectangular interior space. I drop the plate assembly over dowel pins on the punch table to align. I will try to post a better picture showing the lead.

Have you used different quages of material in it? Did that make a difference?--- 20 and 18 gage CR I have used without any difficulty, but if I use either of those in AK I get a bad shear edge. Needed to close up the clearance. The AK is softer and forms differently.

Hope this answers your questions.

Ron Naida

[Kerry Pinkerton]

Ron, just a suggestion. You're gracious enough to comment in your photos but the blue text on a dark background is sometimes unreadable. Can you easily use a different color on dark backgrounds?

[Ron Naida]

Kerry,

Point well taken, I'll work on that.
I must have gotten the text color choice confused with the reflection from the Viagra bottle.

Ron Naida

[Gene_Olson]

But Ron,

That's Milk of Magnesia Blue.

G.

Originally Posted by Ron Naida

Kerry,

Point well taken, I'll work on that.
I must have gotten the text color choice confused with the reflection from the Viagra bottle.

Ron Naida