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So I'm all about pushing the limits of DIY fabrication, and the thought crossed my mind to try out one of the more intensive manufacturing techniques: metal stamping! I've had quite a bit of experience with 3-axis CNC Milling, so I decided to try my hand at making some stamping dies.

I'll be doing some more complicated stamping in the future, but to start out I wanted to make something a little bit on the smaller scale. I decided on stamping out a simple metal watch face out of some thin aluminum sheet I found lying around. The materials cost me only around 5 or 6 dollars, although I admit that access to CNC machines and tooling is not included in that sum. I'm hoping, however, that the lessons I learned from this project will be valuable to the DIY community, especially as I continue to explore more DIY-friendly improvements to this process.

I would love to hear your feedback or any experiences you've had with this and similar processes. I'm hoping to share everything I learned but I'm also hoping to learn anything I can before I try some more involved projects!

Here's a quick run-down on the materials and tools I used:

Materials:

.019" Aluminum Sheet (not sure what series of aluminum it is, but the label on the box said that it was some sort of photosensitive aluminum?) - I used about 4"x24" of the sheet for this project

2.75" Diameter Steel Round Bar (Mild steel) - I used a length of about 2-3" total (approximately 1.5" per side of the die)

.100" Stainless Steel Round Bar (Hardened Steel) - I used two 3" lengths

Tools:

Haas 3-axis CNC Mill (3/8" Flat End Mill, 1/4" Ball End Mill, 1/8" Ball End Mill, .100" Drill Bit)

Hydraulic Press

Flathead Screwdriver (to pry the dies apart)

Propane Torch (we'll talk about this in detail later)

Step 1: Make Your 3D Model

First, I made 3D models for the positive and negative dies. I use Fusion 360 since it's free for students, hobbyists, and startups. For those of you that are not very familiar with 3D modelling, this is an excellent program to get started with. There are tons of "how-to" videos and a great support system with answers to any questions you might have.

This is a good time to mention the offset between the two dies. Since the sheet metal has thickness of .019 inches, there must be a "gap" between the two dies that allows the sheet metal to "fit" during the stamping process. While it would be possible to include this offset in my 3D models, I decided to incorporate it later on in the process. This saved me subtracting .019 inches from all of the geometry used to make the 3D model (or from figuring out a scale factor that would match the .019 inch offset).

Depending on the capabilities of the programs you may or may not have access to, this offset may be included at various steps in the process. Just remember to include it! Without this offset, your die may end up cutting your sheet metal instead of forming it to the desired shape.

The last thing I would like to point out on this step is that you want to design your model with your tooling in mind. What that really means is that if the smallest tool you can put in your CNC machine is 1/8", you can't make any features on your 3D model that are smaller than that. There's no use in designing something that you can't make. So be aware of your limitations and then get to it!

Fusion 360 Stuff:

http://www.autodesk.com/products/fusion-360/featur...

https://www.youtube.com/user/AutodeskFusion360

Step 2: CAM Your Model

CAM is an acronym that stands for "Computer Aided Machining". In this step, I used my 3D model to create a series of "tool paths" to be able to create the two dies. These tool paths, along with pre-determined speeds and feeds, will determine how the steel blanks will be cut and formed into the final product.

The CAM program I used is called MasterCAM. Personally, I find MasterCAM intuitive and straightforward; it gives me all the control I need, even with the complicated surfaces we'll be dealing with in this project. Fusion 360 comes with its own CAM software (which is super convenient because you don't have to worry about any file transfer, etc.), but I haven't had enough time to play around with it and get comfortable with how it works, so I decided to stick with MasterCAM.

Without going into specifics, I'll explain my approach to the CAM/CNC process for this step:

I didn't want to take too much time cutting these dies out, but I did want a good surface finish. I decided to use a 3/8", four-flute HSS finish endmill to remove the bulk of the material, and then I cleaned up the surfaces with a four-flute 1/4" ball end mill and 1/8" ball end mill.

This is where the offset comes into play. MasterCAM has a setting that controls how much material is "left" between the cutting edge of the tool and the edge of your 3D model. In order to create the offset, all I had to do was tell it to "leave" -.019 inches of material on the edges. Well it turns out that "leaving" a negative amount of material really corresponds to removing an extra .019 inches, which is exactly what we want! If you decide to go about it in this fashion, remember that this only needs to be done on one of the dies. If we were to have done it on both sides, the offset would have been .038 inches and the metal would have had too much room to wiggle around.

It's time to CNC! After preparing the two steel blanks and placing them firmly in the vise, I was ready to run the CAM program and watch the 3-axis Haas CNC do all the work! Each side took about 45-60 minutes, but I can only imagine that with larger dies it could take hours to get a good-quality finish.

Step 3: Lessons Learned While Making the Dies

So here are some pictures of the finished dies, and I'll explain a few lessons I learned from this process.

Big Lesson #1: Just because you want these dies to mesh together perfectly doesn't mean they're going to.

So I pulled my two dies out of the CNC, slapped them together, and voila! They fit together just right. It was a very fulfilling moment. I then had the unfortunate realization that if the two sides weren't lined up perfectly, pressing down on them with thousands of pounds of force would result in any number of undesirable outcomes. I also realized that I had no way of ensuring that they were lined up perfectly. So my quick remedy was to drill two holes through the dies and feed two stainless steel rods through these holes. These rods would allow the two halves to "index" into the right position every time. Moral of the story: have some reliable way of making sure that your dies line up.

Big Lesson #2: This is a DIY project after all, so there's no need for overkill.

When I used the 1/8" ball endmill to cut the cleaning passes on the dies, I used a "stepdown" of .004 inches. That means that if a die is .5 inches deep, the machine would make 125 trips around the profile of the die before reaching the final depth. Hopefully the pictures can help you see what I'm talking about, but basically I found that these "stepdowns" were totally redundant. I probably could have increased the stepdown to .008 or .010 without noticing a difference in the final, stamped watch face. This would have significantly decreased the cutting time to make the dies. Next time, I guess!

Step 4: Preparing the Sheet Metal for Stamping

For this particular set of dies, I needed a piece of sheet metal with a few features to ensure that it would stay in the correct position during the stamping process. The rectangle has a large hole in the center and two semicircle indentations on either side. These indentations line up with the two steel rods, and the hole in the center lines up with the extrusion in the middle of the positive die. The pictures should help clarify.

You may ask: why would you put a huge hole right in the middle of your piece? Initially, I was under the impression that having the hole there would relieve some of the stresses in the metal during the stamping. We'll talk about this in future steps, as this will come back to bite me in the butt. Thanks to some great feedback from the Instructables community, however, I was able to change my ways and improve on this step of the process. To see what I'm talking about, check out steps 8-10!

Step 5: The Stamping Process

It's time for stamping! This process is pretty straightforward, it basically consists of three steps:

1. Place the sheet metal in the correct position on the positive die and slide the negative on top! It's like a little metal sandwich!

2. Find a long, metal cylinder that will fit between the two stainless steel rods. Place this cylinder on top of the metal sandwich and place the entire assembly under the press.

3. Cross your fingers and engage the hydraulic press!

The video isn't too exciting, so we'll get to the results in the next step.

Step 6: Results (Round 1)

Complete and utter failure. Isn't it great?

On the bright side, we know that the dies match up because there wasn't any binding going on during the stamping process. In fact, I was surprised by how easily the two halves separated.

So there were a number of tears, most of which stemmed from the large hole in the center of the sheet. So basically, for all the stress that the hole relieved, there was still too much stress for the aluminum to handle. The other areas on the watch face formed pretty well, but unless torn watch faces become a new trend, I think we're gonna need to give it another shot.

Step 7: Results (Round 2)

So, it turns out that our failure from round 1 was probably inevitable. Why? Because we used aluminum (and we didn't use any lubrication, but we'll talk about that a little bit later). Aluminum is notorious for tearing or cracking when it deforms. Additionally, without knowing the specific series (or "type") of aluminum, it's hard to know exactly how it's going to react to our stamping. So, before taking another shot at it, I decided to do the only thing I could think of: heat it up! Heating up the aluminum (just shy of the melting point) and allowing it to cool will "anneal" the material. This annealing process will "soften" the aluminum and make it more ductile.

The same process was followed as in the previous stamping attempt, except that the aluminum was heated up with a propane torch prior to the stamping.

And voila! It worked! Mostly. There were still a few tears, but luckily these were near the bottom edges of the watch face, where we wanted it to remove anyway. Looking closely at the edges of the stamping, we can see that the aluminum is pretty close to giving way, but it still managed to stay together. Also, the back of the aluminum discolored quite a bit from our makeshift heat-treatment. This was most likely due to the surface treatment it had received as "photosensitive" aluminum, however.

I was pleased with these results, but there are still a few opportunities for improvement. First and foremost, the main hole was warped in the stamping process and isn't quite circular. In future iterations, I would decrease the initial size of the hole (which would involve adjusting the dies as well, unfortunately). This would leave enough extra material so that after all is said and done, I could punch out the finish diameter, leaving a perfect circle.

I hope to repeat this exploration process with a similar thickness of stainless steel, and I hope to be posting those results soon! Please leave comments with your experience and expertise so that we all can get a little bit better at metal stamping.

Step 8: Adjustments/Improvements!

I got a ton of good feedback and advice from the Instructables community on my first seven steps, so I decided to make some of the advised adjustments and see how it goes!

First of all, I received a lot of commentary on materials. notingkcool, bpark1000, sailor_sid, and others made valuable comments on the complicated nature of aluminum heat treatment, so I decided to try a out a more resilient material: stainless steel! Call me lazy but I had the feeling that using stainless steel would save me from the frustration of heat-treating the aluminum. And it just so happens that my friend had a bunch of .019" stainless steel sheet hanging around! He let me borrow enough for a few blanks and so I took another shot at it!

A number of comments also involved or hinted towards the use of lubrication (Prfesser, carl5blum, KarcsiS1, and others). I didn't have die lubrication on hand, so I ended up using some "Way Oil" (the oil used to lubricate the ways on mills, lathes, etc) to lubricate the metal blank as well as the two halves of the die. I made sure to apply a very thin coating so as to avoid the entrapment of oil bubbles within the die.

Carl5blum mentioned the removal of the hole from the initial blank, which required some adjustment to the die. I stuck the die in the lathe and removed the central column from the positive die. Luckily, no adjustments to the negative die were necessary. This change, however, requires the hole to be punched after the stamping of the watch face.

Step 9: Results (Round 3)

The attempt with aluminum (lubrication, no heat treatment) was almost successful! But not quite. Looks like heat treatment would have to be involved in order to make it work for this specific series of aluminum. The lubrication, however, did cause significant improvement in the results.

The attempt with the stainless steel was fantastic! It did get stuck a little bit in the negative mold, but I was able to remove it with a reasonable amount of force. The surfaces looked great, the edges were clean, and there were no tears whatsoever. The edges of the blank suffered from quite a bit of the potato-chip effect, as I have not yet been able to design a corresponding pressure-plate (as suggested by carl5blum). I look forward to incorporating a pressure plate in future stamping endeavors!

Really the only downside with using the stainless steel is the wear on the die. Because the die itself is made of a mild steel, repetitive stamping of stainless will eventually wear down on the edges of the dies. Luckily, I'm not going into production any time soon so I won't need to worry about that!

Step 10: The Final Result!

In summary, if you're going to try metal stamping in the future I would suggest shying away from aluminum (unless you also have the resources to correctly heat-treat your aluminum). Steel just seemed to be more resilient and fit for the task. Additionally, I would agree with the comments of many of my fellow DIYers in saying that lubrication is an absolute must. It really does make all the difference.

The stainless steel face turned out to be quite beautiful in my opinion. The lubricant allowed for smooth forming of the metal, and the sheen of the stainless wasn't marred at all by the process. Makes me wish I was actually building an entire watch!

Thank you once again for your input and advice; I enjoyed implementing the changes and seeing the results improve. It's another testament of what a great DIY community is capable of. Feel free to continue sharing advice and pictures of your own metal-stamping endeavors!
<p>I wonder if you used a sledge hammer instead of a press that it would work better. The shock of the hit versus the slow pressure of the hydraulic press. </p>
<p>Hello Blanchae: Quite the opposite, at the shop I worked they bought a hydraulic press to have more control of the ( slow ) speed. With the crank presses they could change the motor pulley, but that only helped a little. On progressive draw dies they might have 5 draw steps before the part reached the finial shape. Press work can be neat! Carl.</p>
<p>You need to look what aluminum do you have. Often the easyer alloys to forge are 5xxx( Al -Magensium), 3xxx (Al - Manganese) and 1xxx (pure aluminum).</p><p>This alloys can't be heat threated, only anealed and work hardened. They usually come un O condition (the softer state) and have a good cold workability.</p><p>Other alloys like 2xxx and 6xxx can't be deformed too much without breaking, i learn it the hard way. Only way to work this alloys are by stepped forging or, easyer, Isorhermal Forging.</p><p>Isotherman forging is when you heat alloy and die between 200 to 400&ordm;c (depending on the alloy, max % of deformation, pressing force, etc).</p><p>There are curves of forging pressure/temperature for many alloys on internet and on books like the ASM Metal handbook</p><p>You can see this process here at 0:54<br><iframe allowfullscreen="" frameborder="0" height="281" src="//www.youtube.com/embed/GY9vN9oFbUQ" width="500"></iframe></p>
<p>Sweet video! I just added a few more steps recording my attempt with stainless, but it would be interesting to try out some different stamping/metalworking techniques in aluminum.</p>
<p>I just saw the try with stainless. It looks great!</p><p>Probably the alloy thay you picked was in a softer state than aluminum.</p><p>In my case i had to make aluminum cones of about 3/16 thickness.</p><p>The firsts try was good because i had an 3003 alloy, lubrication was a big difference to me too.</p><p>But the second try we had 6061 aluminum, and it was impossible to forge.</p><p>Now i have to build an oven and the die heaters to forge that pieces.</p><p>Alloy datasheets will give you a guess about how much easy to form a metal is, look for the &quot;Elongation&quot; data. In my case 3003 was about 20% and 6061 was 10%, and 7075 was 7%. That's the max deformation that the probes allow before breaking.</p>
<p>Knowing the properties of the metal you're working is kinda important. If you had used an off-the-shelf stainless steel shim stock, you might have had different results. For this application stainless steel, annealed is what you want. On the issue of wear on the tool, there are MANY grades of tool steel. Some specifically designed for prototyping form dies. There are numerous tricks and procedures to getting the metal to move the way you wish. You have a very good start. It's been a fun Instructable!</p>
<p>This is really high quality work, I'm impressed. I don't know if there are rules on this site if you can make metal stamps on request ineverfinishanyth?</p>
<p>Unfortunately the machines I have access to aren't for commercial purposes, so I wouldn't be able to make one for you. Sorry!</p>
<p>Hello: As a former Die Maker I would like to suggest changing the shape of your blank. Also we would have a pressure plate hold the edge of the blank to avoid wrinkles around the edge. We also would have punched the center hole after drawing the shape. Lubrication is a must. Impressive work! Carl.</p>
<p>I just added a few more steps with several of your suggestions in mind! Thank you for the feedback, it helped a ton!</p>
Thanks for the feedback, this is exactly the kind of information I was hoping for! I would love to pick your brain some time about your die-making experience
<p>In the automotive industry they are using thin film of **** OIL**** to avoid the cracking . Try it with oil and without heating, maybe it helps :)</p><p>If it helps i can ask my friend wath kind of spetial oil they are using. </p><p>Nice work my friend</p>
<p>Just added a few more steps with some of your suggestions in mind! Thanks for the feedback!</p>
Do you plan on actually making this into a watch? Would be good to see a finished outcome, I guess you need to make and press the back also and find glass and mechnism.<br>Also is there any reason other than material cost that you couldn't use silver or gold i would have thought it would be easier to work with than aluminium (UK spelling ?)
<p>Unfortunately I don't plan on making an entire watch, although after my most recent attempts with stainless steel the process does seem a lot more approachable. As far as silver and gold go, I don't have experience with either so I'm not sure how they would respond.</p>
<p>Drawing lubricant is wax based, so a light smear of wax on both side of the blank should help. Try mild cold rolled steel before you do stainless. Next die; incorporate the guide pins into the design and the holes can be drilled while the piece is still in the vise. Your center hole will grow larger due to the direction of the metal movement. This is why holes are sometimes done in a separate operation. Don't worry about the blank moving; it will anyway, and might break your guide pins. The center hole is enough. Once you apply pressure the metal will flow where it will. Oh, and by the way, a watch face is not a &quot;simple&quot; shape! Very nice work!</p>
<p>Just posted a few more steps with some adjustments/improvements! Thanks for your feedback!</p>
<p>You comment about heating and to &quot;stamp quickly&quot; as the metal is cooling. I maintain that no matter how fast you stamp, the metal will have cooled. What made it work is that the metal was annealed by the heating step, and it doesn't matter how long you wait after annealing; the metal will flow better.</p>
<p>Great point! I hadn't even thought of that!</p>
Another thing about annealing aluminum. Aluminum, unlike iron, has annealing temperature dangerously close to melting point, and aluminum doesn't &quot;show colors&quot; like iron when heated. So you risk melting the thin sheet. One way to get temperature indication is to cut air to torch so it smokes, and lightly soot the aluminum. Then, admit air and start the anneal, slowly. You are done when the carbon just burns off. Don't smoke the metal heavily, or the warning will come too late!<br>If you use 6061 alloy, you can re-heat treat it back to hardness by heating in oven at 350F for 24 hours, then allowing it to cool in open air. Several weeks later, it will be hard to &quot;T6&quot; condition.
<p>When I was at school a long time ago my teacher said put soap on the aluminium. The soap goes black just before it melts. </p>
So cool, can't wait to see what you press next. Oh how I wish I had a CNC router of my own!
<p>*CNC mill </p>
<p>Great, thank you for posting. Very nice dies I would like some instruction on machining them.</p>
Message me with any questions you have and I'll try my best to answer them!
<p>In moldmaking, we call it &quot;registration keys&quot; that allow the two negs to line up at the end. Just an additional couple semispheres or whatever, placed strategically around the rim. this is awesome thanks for posting!</p>
<p>I'm wondering if you could use some sort of thread cut in the center and drive the two halves together with a drill. Would you be able to get enough torque on the stamps?</p>
<p>That is very cool, thanks for sharing it :)<br>I've been thinking of using my 3D printer to make molds for resin casting... it hadn't occurred to me that I could probably go the next step from there and do metal stamping too... wow, the future is shiny! haha</p>
<p>I would love to see how much you can improve on this (by yours truly) with decent equipment:</p><p>https://www.instructables.com/id/Extruded-Holes/</p>
<p>Hello Again: Cool Shape, did I mention I had worked at Speidel? Carl.</p>
Thank you for sharing! Will have to keep this in mind in the future
Interesting! I've done similar using 3d printed dies (high infill) and aluminium sheet.
<p>WOW! So incredibly awesome! Voted in all contests this is truly brilliant!!!</p>
<p>Well done!</p>
<p>Nicely done!</p><p>A suggestion: aluminum beverage cans are made by pressing in stages:</p><p><a href="http://www.my.all.biz/img/my/catalog/25321.jpeg" rel="nofollow">http://www.my.all.biz/img/my/catalog/25321.jpeg</a></p><p>I don't know how practical it would be to make an intermediate die of shallower depth...Also, the aluminum and die are well-lubricated before pressing. Might cut down on the tearing.</p>

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