Jewel Box Quilt Blocks-HELP
 

I'm in the process of making a king size Jewel Box quilt. I have my scant 1/4" set and have assembled the HST and the 4 patch units, they measure 4 1/2" x 4 1/2" (perfectly :)). When I sew the 2-HST and 2-4 patch units together to make the 8 1/2" x 8 1/2" block is when things go wrong and the blocks are not squaring up they are short sometimes by as much as an 1/16th of an inch, which will not translate well across a king size quilt! I'm ready to tear my hair out! Where am I going wrong?? TIA

That doesn't seem too bad actually. If you are doing all the blocks and they are consistently 1/16 th of an inch off you will not notice even if the quilt is a tiny bit smaller then if they all would have been 8 1/2 inch blocks. when you sew them together make sure to piece them and "stretch" them to fit each other where they should meet. Also sew them together in blocks, like 4 blocks making a larger block etc. and making the blocks larger versus doing strips or long rows. Then when quilting, hammer them in place. LOL Lots of quilting to make them stay put. You'd be surprised how much you unevenness you can hide quilting.

We talk about a quarter inch seam, but remember, you don't measure the seam, you measure the resultant patch. take a minute to double check your seam setting:
http://www.quiltingboard.com/tutoria...ce-t89997.html
If your starting patches are the correct size, and you think your seam allowance is correct, you may need to take a slightly narrower seam because there are additional seams in the patches taking up room.
Another thing to check is that you are not ironing in a tiny crease in the seam when you press.
The only other thing I can think of is if you are now using steam and the patches are shrinking a bit. This can happen if you don't prewash.

Thank you for your response! :) Yes, I had actually thought of "stretching" them to fit but got nervous about the discrepancy being too great over the whole quilt. I had already decided to put 4 of the 8 1/2" blocks together to make an even bigger block, got mind-boggled by how I was going to square up those.....is there such a thing as a 16 1/2" square up ruler? :shock: I believe I am over-thinking the whole process and should just "march" on and know it will all be taken care of with LOTS of quilting! :D
Have a wonderful New Year!

Thank you PaperPrincess. Yes, I am sewing on my 301A and achieved the scant 1/4" with Bonnie Hunter's method. The patches are correct, it's when I sew the 4 together that things go wrong. I have thought of narrowing the the seam allowance a bit as you have suggested but am worried that it will come apart as it is going to be used as a bed quilt. I am pressing my seams open with a dry iron and I did pre-wash the fabric as I am using Batiks. I so appreciate your input :)

Yes there is a 16-1:2" square "Quilers Rule TM square-block lap board". Very handy! I inherited mine so don't know where she got it.

Thanks, mom-6! Off to search the internet.......

Sometimes when I am piecing and have an extra small seam allowance due to my errors, I sew it with a straight stitch to fit the other pieces. Then I go back and zigzag the seam allowance with the left side of the zigzag touching the straight stitch. I feel like this will keep the seam from fraying out in the future.

The more seams in the block, the more likely it is to be a tad smaller. I am working on one now that has up to 120 pieces in a block. So far, so good. But I have been taking one .1 mm smaller seams as I get to the outer rows. Seems to be working.

I even have a 20 1/2 square up ruler, got it at some quilt shop, and I use it a lot.