I have these perfect laser-cut acrylic templates to make this Rose Dream quilt block (for a 6" block). Now I need to create illustrated instructions to make the block from fabric. Been doing this for years, so the instructions are not the issue. I created the block quickly in CD, no problem. However, when I checked it against the acrylic template, the arcs of the lens-shaped piece did not match. Took me awhile to understand that the creator made the template a specific width, so it's not a 90° arc.
So...the challenge is to create the block so that with of the arc is 2.00" (that would make the height of the arc 1.00"). If you're bored or curious to try, I've attached a PDF with a few more details. BTW, I think I found a way to do it, but I'm curious to see if someone comes up with another way. Just keep in mind...all the geometry I know, I've learned as a quilter. My hubby told be this is really trigonometry. RoseDream_challenge.pdf
Here's what I see when comparing the methods described in this thread:
Yes, I could see the differences too. The overlapping circles method does not fit within the 3" square, but it matches the template. My method of adding a center node to a 90° arc and pulling it up to 1" looks good, and if I made the templates, I use it or the 3-pt arc method. It's interesting to see the different methods though and it's all very educational! Learning a few things too.
Thanks Eskimo
John, if you hold Ctrl whilst using the 3 point curve tool you'll get a true arc of a circle, not an ellipse.
Here's how I would have done it.
Draw the large square
Draw the smaller two corner squares to the required size
Draw a line from the inner corners of the two smaller squares to create a diagonal (You could use a 45° Guideline but I'm going to use the centre point of this line later)
Off to one side I draw a horizontal line, and set the line length to 1" using the Transformation docker/tool of choice
Rotate the line 45°
With Snap to Objects ON I grab the 1" line by the lower node and drag it to the 'center' of the diagonal line I drew previously. I now have the 1" offset set up
With the 3 point curve tool I click on one end of the diagonal line and drag to the other end of the line, release the mouse button, then with CTRL held I click the outer end of the 1" line.
Duplicate the new arc and shift select the outer large rectangle
Click and drag the top right bounding box handle and drag to bottom left.
Delete the temporary diagonal line and the 1" line.
Took me way longer to type than to do it.