I was inspired to make my own bead material by reading the series of posts here, here and here. I was glad I did. Her idea of using the plastic grid as support for the squares and cubes was very helpful, and I'm glad I had her tip before I started about starting the cubes in the center and spiraling out. It can be pretty tricky fitting everything into place anyway. I imagine it's even trickier if you start from the sides.
After looking at a lot of different options, and after a lot of thought, I decided to buy 8mm beads from Consumer Crafts. As I've mentioned before, I already owned some bead squares I bought off ebay when I saw a good deal, so my biggest dilemma was deciding how much I wanted my bead bars to match my bead squares versus how much I wanted to spend. Round, opaque beads cost quite a bit more than transparent, faceted beads. If you're starting from scratch, this isn't as big of an issue. I finally decided that cost effective was more important to me than a perfect match, and if they were close enough to what I had, there probably wouldn't be any confusion.
Next I had to decide what size I wanted. Montessori at Home says 8mm. Another site I looked at said 6mm. Gettman says “about 7mm.” It's too bad none of the places I looked at sell 7mm beads, because I think that would be just about right. Again, I wanted them to be fairly close to what I already had, which looked like they were closer to 8mm (really, how do you measure a round bead that accurately?), plus I wanted to them to be close to the size of the squares in my decanomial. I was also worried about how they would fit in the plastic canvas. Since it was Montessori at Home that had suggested the canvas, I decided I had better go with the bead size she suggested too. I don't know whether it was the brand I bought, but it turned out my 8mm beads were just a little too big for the canvas. They will still fit, but by the time I got to the corners of the thousand cube, there was some bulge (don't know whether you can really see that in the picture). (They are also ever so slightly bigger than the beads I already had, but that might just be because of the nature of the faceted surface.) My guess, then, is that you can probably get away with either 8mm or 6mm beads if you're using the plastic canvas. The 8 will just bulge slightly, and the 6 would probably have a little bit of a gap. If anyone tries it with the 6mm beads, I'd be interested in hearing about it. The smaller beads are quite a bit cheaper.
One more thing to consider before you purchase your beads is exactly what materials you want to make. As Montessori at Home points out, a homeschool doesn't need all of the bead materials. It's probably a good idea to have a rough idea of your math plans before you start. I decided that I don't really need the bead chains. I just wanted bead bars, squares, cubes, and the golden bead material for learning about the decimal system. Actually, I had been planning to just buy the bars and golden bead material, because the cubes are so expensive to buy, so I'm pretty happy to have found a way to make them easily, because I think the cubes are a pretty cool way to have an easy relation between the math materials and the sensorial materials.
I decided I wanted at least 20 of each bead bar, or enough to fill the decanomial, whichever was bigger. So for the first five sets, that's 20 bars each. For the 6's I'd need 30. 7's would be 42. 8's would be 56. 9's would be 72. 10's would be 90.
Oh, and I will only be making one thousand cube. I plan to buy a set of nine wooden thousand cubes to complete my golden bead material, because I calculated it would cost $30 just for the beads if I made nine golden bead cubes, so it's a lot cheaper just to buy the wooden ones. I would definitely recommend making or buying at least one golden bead thousand cube, though. This is the epitomy of attractive material. Everyone at our house, from the baby to the daddy, has agreed that this big shiny cube is hard to take your eyes off of. I wonder how many more kids would like math if they had shiny, golden cubes to work with.
Enough beads for that much of the material cost me $38 (including shipping) from Consumer Crafts. All but the white are clear, faceted beads. They did at least have the white in opaque, which is nice. At another place I looked at, the closest they had to white was “crystal” which I worried wouldn't be similar enough. If anyone is interested, I can do another post about exactly which colors I bought and how they compare to the ones I already had.
Wire is going to add a bit to the expense. I had a good-sized spool already, which I managed to use almost all of just making the thousand cube. The label was gone, but I think it was about 18 or 20 gage. It worked okay but was a little thinner than I would have liked. I think slightly heavier would be better, maybe a 16 or even 14 gage*, if you can find it. You wouldn't want to go too much heavier, though, or it won't fit through the holes of your beads.
I found it was easiest for me to twist one end, then measure how long I would need for whatever number of beads I was doing. After I had a pretty good idea what length would work well, I'd keep one wire as a template:
and use that to measure and cut a whole bunch at a time, always twisting one end before measuring.
Since I knew I wouldn't be twisting the exact same size every time, I figured this would give me a more consistent measurement than if I were to just measure straight lengths. Plus, having a pile of these with one end already twisted makes beading several bars (or a square or cube) go really quickly.
This is a project I will probably be working on for a while. I'll let you know if I have any more tips or problems and share pictures when it's finished. I'd love to hear about it if anyone else decides to make their own bead material.
*Update: For more details about wire, see this thread.
Show off your own homemade Montessori materials: