Figuring circle size

[Donna N.]

I am working on a mariner's compass block that is surrounded by flying geese (from the latest Quilter's Newsletter magazine.) I want to apply the background using an "inset circle" rather than appliqueing the circle of geese to the background. Here's where I'm stuck.

I need to figure the size of the background cutout with seam allowance so it will fit nicely around the circle of geese to square off the block. (Does that make sense?)

Do I take the circumference (including seam allowance) of the circle of geese minus a half inch to get the size of the cutout circle? I'm not good at the math, but it seems that would be how to figure it. Please tell me if I'm wrong or if there's a simpler way to calculate this. Many thanks in advance.

[karen f.]

I have the EasyCircle cutting ruler thing and it says to cut the hole 1 inch smaller than the circle that is going into the hole.
Karen (Oh yeah this would be sewn with a 1/4 in. seam)

[Donna N.]

Thanks for your help. I saw the directions on the Easy Circle and 1 in doesn't sound right, but I'm not a mathematician, so I think I'll take some scrap fabrics and do a test run. :-) I'll post the results of the test later.

[karen f.]

I agree with you about it not sounding correct but I remember when I got it I tried my way and theirs and mine never worked out right but their way did. It still doesn't make sense to me.

[Donna N.]

Tried and true. I'll take your word for it (but the skeptic in me still wants to try a practice piece -- sorry.) Seriously, I never would have figured to add a full inch.

[Donna N.]

I would think U need to figure the circle the same way U do for a square block since the seam goes all the way around, thus 1/4 inch for each side = 1 inch. That is the way I would have looked at it. Good luck and cain't wait to see how it works for U.

Linda

[Donna N.]

I'd try it with paper first before I cut into fabric

[Sandy F.]

When I did the background piece for the Mariner's Compass I am working on I drew a circle for the finished compass on the background fabric. This was my stitch line. I also made some registration marks so I could put the compass in hopefully straight. I cut out the inner circle a generous quarter inch from my stitch line. It worked but does it make sense when I explain it.

[Patti P.]

tkwrtr are you working on the Mathieson quilt that is on the cover? Her quilts are spectacular and I keep admiring the look of precision of her work. Hope you share pics of your quilt.

[Donna N.]

Yes, I'm making the center compass that's featured on the cover. Can't wait myself. Too bad I have to "work for a living." :-)

[Donna N.]

For those who helped me with the circle dimensions, thank you!! I finally got around to trying the diameter minus 1 inch and it WORKED PERFECTLY. I never would have believed it, but had absolutely no problems sewing the center into the circle.

Thanks again!

[Gloria H.]

Now I have a question. I am working on a sampler quilt and using templates for the blocks. The finished block is a 1/2 square triangle measuring 2 1/2 inches. I don't like sewing the bias. I'm much more comfortable sewing the block with contrasting right sides together and sewing 1/4 inch either side of a diagonal line down the center then cutting apart on that diagonal line. What I don't know how to figure is the size of the square needed to get 2 21/2 inch 1/2 square triangles. I think it is one of those funky 7/8 inch measurements. I am mathematically challenged and this is driving me nuts. Any help would certainly be appreciated. Gloria

[Gloria H.]

So Gloria, if your half square triangle finishes to 2 1/2 inches, then you would cut your two squares 2 1/2 inches plus 7/8 inches, which would be 3 3/8 inch squares.

Hope this helps.

Dana in Olive Branch, MS

[Gloria H.]

I prefer to cut squares that are one inch larger than the finished size I want, draw a line diagonally on the light square's reverse side, put the squares right sides together, sew a scant quarter inch from each side of the diagonal line, then cut on the drawn line, and press the two half square triangles open, then trim to the exact size. Much more accurate for me.

Pat in Rockport, TX

[Gloria H.]

Wooo hooo. I knew you guys would help. Thanks so much. Now I am going to post that formula in big numbers by my cutting table. Gloria