All seams are 1/4".
Start with one of your triangle centers and choose a strip to use for your first round of logs. Sew the strip to one side of the center, right sides together but before you do make sure that the strip extends far enough on either edge. Do not line the edge of the strip up with the tip of the triangle. In the photo below the black lines show where the strip needs to extend beyond.
Press the seam open and press the edge of the strip over 1/4" about 1" beyond the edge of the triangle as indicated by the arrows in the photo below. This will help keep your edges "squared" ("triangled"?). If you don't do this, the ends of the strips tend to bow out, away from the center.
Trim the ends of the strip, in line with the edges of the center.
Repeat the previous steps two more times to complete the round, making sure that each new log extends far enough beyond the edge of the block. Keep a small ruler or other straight edge handy to check that your strips are aligned.
Continue with a second, third and maybe fourth round until your block is at least slightly larger than your template. For the larger, outer rounds you will obviously need longer pieces than for the inner rounds. I would piece strips together, end to end to make them long enough before I would go back and cut another strip but if the piecing bothers you, by all means cut more.
HOT TIP: Keep your template next to your machine so you can check your progress as you add rounds. I did not do this with the block below. I ended up with a pyramid that was not quite at the edges of the template.
If this happens to you I recommend trimming the edges of the triangle (you can use your normal acrylic ruler lined up with the inner seams) and then adding a final round.
When your block is large enough, lay your template on top and center it, using the black guides. Each line should pass through the corners of each round of triangles like the photo below.
If you can't quite get the guides to match up with the corners don't panic. Fabric shifts and stretches and it happens. It's most important to line up the outermost corners (the pink ones in this case).
Trim around the template and you're done!
You can find the rest of the quilt along at the following links:
And you can share your progress in the Flickr group, here!