Determining the Length of a Riveted Bangle
So, I want to just first talk about what is a rivet, and I'm gonna show you guys our two little examples here. So, basically a rivet is just a piece of metal that goes through and pinches our two or more layers of metal together, so it's a type of cold connection. Cold connection meaning connecting without heat, and you can see here if I were to show you... If we looked at the backside there, we can see it comes through the backside, so you can see them there as well. You can make rivets out of wire, which is what this is, or rivets out of tubing so that you get that kind of open effect. For what we're doing here, there isn't a reason to use one or the other, other than it's decorative qualities, right? So, if you don't want holes in your design you're gonna want to do what's called a standard rivet or a wire rivet, but if you like that look of having the holes in there, then you might want a tube rivet. As you'll see as I do the demos, I personally think tube rivets are easier, which ...
is why I use them. But that said, there's really not a strong advantage or disadvantage to either. What's really great about them is that they allow us to create a continuous bangle without using a torch. So, the first thing we have to figure out is how long our bangle blank needs to be, so how long our strip of metal, and for these examples I just used very simple rectangles of metal, but there is no reason that you can't use this technique and layer it onto some of the more complicated techniques we've talked about. So, if you wanted to do a bangle that had a lot of piercing, or let's say... Actually, this one is a great example, right. If I wanted you to do this, something like this shape as a bangle, could completely do that with this rivet technique. So I could just make this longer, bring it around. So even though I'm showing you guys these on rectangular shaped pieces, there's no reason that you can't do something more interesting with the shape of this bracelet. Thinking back to our design principles, you know, we've got a shape this way, but we can also think about shape around the bracelet. And you'll notice that even though I kept this fairly standard I couldn't help myself and I had to put this tiny little decorative detail in there just because it was more fun. So, of course I could've made that a flat. This could've been a straight line, perfectly fine, but I just wanted to add a little decorative detail in there. So you can really think about your rivets as a way to add some visual interest to your bangles as well. All right, so let's talk about how long your bracelet blank needs to be. So, you have a couple of options here. Truthfully, I am kind of a, "Let's just guess "and play and figure it out..." But for those of you who like precision, I want to give you guys a little bit of math. So, what you want to do is you want to start with the inner diameter of your bangle. Now, if you're making this for yourself the easiest thing to do is find a bangle that you already own that fits you well, and generally what you want to look for in a bangle that fits you well is you want it to just barely fit over your hand so that it doesn't have to be so big on your wrist. This is actually way too big of a bangle for me. This size, you can see, this guy is significantly smaller. This is probably a better bangle size for me. It's a little bit tighter, so it's not gonna be so huge on my wrist. Some people, truthfully, just have a really hard time wearing bangles because they have big hands and skinny wrists, and so if that's you or that's someone that you're trying to make jewelry for, a bangle may not be the best type of bracelet. That's why we're talking about a few other kinds, but in general you want to find a bangle that you already have that fits you really well. If you don't have that or you are making bracelets for someone else, I've pulled together some approximate bangle diameters because we're using this measurement of the diameter to calculate this. So, small is about... I'm gonna say six centimeters across because that's faster than saying it in inches. But basically what we're doing is we're measuring across our bangle here, and again, there's a cheat sheet for all of these numbers, so if you guys purchase the class you've got all the bangle diameters, you've got all of these formulas, it's all on there. You don't have to remember it. So, what we're gonna do is we're gonna take the diameter of our bangle plus the thickness of our metal, so we have to account for the fact that our metal has a little thickness, so pretty much wherever you buy your metal you can usually get the information, but this is pretty standard, right. So, I think this is probably... We'll call it 20 gauge, so we're looking at about 0.08 millimeters, and I did these in millimeters because honestly to do this math in inches, it's like point blah, blah, blah, blah, blah, blah, two, right. It's like eight zeros and then two. So, in this case it's just easier to do it in millimeters, but if you look up wherever you bought your metal from they'll usually give you the thickness in both. So, we'll take our inner diameter plus our thickness... Someone help me remember that, right. So, this plus 0.08 times 3.14, which if we remember from high school geometry is pi, right, and that's gonna give us the length. So in this case... This is why I asked for a calculator. I was like, "This is a lot of math." And that bracelet diameter goes for round, so if you're making an oval you're not gonna measure this because it's gonna give you too long, you're not gonna measure this way. It's easier to measure a round bangle and then you can just make it oval later, make sense? So, take your measurement off a round bangle. So, this guy... Since I'm in millimeters, this guy is about... And I know I said this one was too big, but that's okay. We're just gonna use it as an example. It's about seven centimeters, so 70 millimeters, so 70 plus 0.08 equals... Nope, yeah, times 3.14, let's see if I did this math right. 223, so 22, which conveniently is not so far off from the length that I have laying on our table now. Look at that, amazing. So that was how I did that math. Does that make sense for everybody? If your bangle is particularly wide, anytime it gets wider this way it gets a little bit harder to put on the wrist, so I would say if it's more than four millimeters wide add another half millimeter to it. If it goes up again to eight millimeters wide I would add another half millimeter to that. So the wider your bangle gets the more I would add to the length, and again, some of this is just a little bit of trial and error. I'm also a big fan of just making a cardboard or paper model, so if you're not sure, make it out of cardboard, wrap it around, tape it together, stick it on your wrist. Right, really easy way to check. So, then the other thing that we need to do after we've figured out that length is now we need to add in an overlap, so when I said this example that I had was not quite... It was a little bit longer than our 22 centimeters that we got, that's because I'm accounting for the overlap that I need to do the rivets, and there's no hard and fast rule for this. You basically just need enough material to deal with, so in the case of this one where I ran the rivets across the bangle, you can see I left about half an inch overlap, but I probably wouldn't have needed to use that much. I probably could've gone as small as a quarter of an inch. Leaving this much material, though, made it a lot easier to work with, as I'm gonna show you guys in a minute, because it gave me more of a surface to tape down and hold it together before I was setting the rivets. You can also orient your rivets this way, in which case obviously leaving about half an inch was definitely the bare minimum of what I needed to get those two rivets in that direction. So it's a little bit of an eyeball. You can see on both of these I added about half an inch, but you can decide if you want more or less.