First, the center triangles. I used mostly neutral fabrics for my centers with a few colored triangles thrown in for fun. You'll need one for each of your full blocks and a half triangle for each of your half blocks (duh). There is a little tricky bit to the half-block centers but I'll get to that later.
Cut strips from various fabrics, at least 2.5", no wider than 6". Line up the 60* guide on your acrylic ruler and cut off the corner like so:
Turn your ruler and line up the other 60* guide with the bottom edge. You can slide the ruler left or right to make the triangle larger or smaller. Cut that sucker.
Turn your ruler again and you can cut another triangle. See how I made a smaller one? (NOTE: in this case I had to trim a little bit off the end before cutting another center to get rid of that blunt corner.) (ALSO NOTE: if you're using scraps for your centers you can fussy cut your triangles any which way you want.)
For the half pyramids you want to use larger rather than smaller triangles. As for the number you'll need for the half pyramids: if the number of blocks in your rows will be odd, just cut another center for each row. If the number is even and the number of rows is even, same. If the number of blocks in a row is even BUT the number of rows is odd, you'll need one for each row plus one. Example:
In my original quilt there's an even number of full blocks in each row (6) and an odd number of rows (5). I needed to cut 6 centers for the half pyramids in order to have enough of the right orientation. Is that confusing? Probably. You could also just cut a bunch of triangles and figure it out later! Alternatively, you could make sure to use a reversible solid for at least on of your side blocks, then you could flip it to be which ever orientation you need.
If you manage to figure all of that out, take your centers that will be used for the half pyramids and cut them in half like so.
Now for the logs in your log pyramids. If you cut your triangles from width-of-fabric strips, reserve the leftover strips to be used as logs. If they are wider than 4", cut them in half lengthwise before using. Cut the remaining strips at least 1" wide, no larger than 4" wide. I recommend cutting two strips for every width that you cut from each fabric. This way you should have enough to complete a small round and a big round of logs without having to cut more.
You can refer to this post to get an idea of about how much fabric you'll need. Again, you'll need about a yard worth of strips for every four blocks you make. Of course, this is an estimate. Just do what I do, cut a whole bunch of strips, cut more as you're piecing if you need them and use any leftovers in the quilt back.
Here are my strips and centers, cut and ready to go!
You can find the rest of the quilt along at the following links:
And you can share your progress in the Flickr group, here!