How to enlarge a block
 

Hi all, I am wondering how to increase the size of a block just enough to be slightly larger than the required size. It seems sometimes when I make my blocks they come out just a hair under even when I take a lot of time carefully cutting, my rotary cuts. This makes it hard for me to square up porperly. I thought I heard Eleanor Burns slightly enlarges her blocks so she could square up more accurately. Should I just make the outside pieces an eight of an inch bigger? I believe I tried that and got my pieces all messed up. It seems that it would be easy to oversize slightly but I can't figure it out. Anyone Have any input on this on how to do this.

I would find it difficult to only enlarge some of the outside pieces. However, guess it could be done with careful calculation and sewing.
Check your seam allowance and make sure you are making the scant 1/4" seams. I find this is usually the case when the blocks don't measure out. Also, measure each section you sew to make sure they are coming out the correct size.

to enlarge a block, on each of the pieces you must first eliminate the seam allowance, then enlarge a consistent percentage on each piece. So, if you want a 4" finished block enlarged to 4-1/2", that is an increase of 1/8 or .125. (Multiply 4 x 1.125). Then add back the seam allowances to each piece.

Not sure if this is exactly what you're asking though...If you're looking to make the block slightly larger, you could decrease your seam allowance a tad. Or when you cut the pieces, use the outside of the line on your ruler instead of centering the line exactly on the edge of the fabric. This should work if you cut all the pieces using the same side of the ruler line and might add enough to make your block slightly larger.

Laurie

first- check to see how accurate your 1/4" seams are---cut 3 strips of fabric 6" x 1 1/2"---sew them together---measure the center strip- it should measure 1" wide- if it does not you should *adjust* your seam allowance until you have it correct.
you can add a smidge (consistant amount) to each piece of a block===but some blocks will simply not go together quite right- some are ok to do that to---then you need to measure & trim with each step of making the block. it is easier to figure out why they are coming out wrong & fix that- you may need to sew a bit narrower seams...or line your ruler up a little differently- like have the lines on the edge of the fabric---not beside the edge.

I have a default setting on my Janome of 3.5 for center and use the 1/4 foot attachment. However, I also find that sometimes my blocks are that smidge too small. To compensate for this, I move my needle to 4.2 (move it to the right), still use the 1/4 foot, and my blocks are always right on!

Love Deb Tucker's rulers and patterns as she enlarges blocks and then cuts them down after sewn. Check her site.

I agree with the comments to check your seam allowances. Here's a good way to check:
http://www.quiltingboard.com/tutoria...ce-t89997.html
Also, what thread are you using to piece? I have found that a 60 weight really helped my accuracy.
And finally, use the same ruler, or at least the same brand of ruler for your whole project.

Besides checking your seam allowances you might want to check your cutting technique. Where on the ruler are you lining up your fabric. You may be cutting the thickness too narrow and adjusting for that will help you. Try it on a few stash blocks and see.

Or just cut larger and trim down if possible. Though not all pieces of a block will accomodate this.

ali

Are you wanting to enlarge for example: a 6 inch block to say an 9 inch block? If so, here's a formula: BLOCK SIZE WANTED (divided by) CURRENT BLOCK SIZE = PERCENT TO ENLARGE OR REDUCE
Example:
To enlarge: Size you want = 12" and Current size = 4"
12/4=3 (answer times 100 = 300%)
To reduce: Size you want = 7" and Current size = 12"
7/12=.58 (answer times 100 = 58%)

What I do is sew a hair off the sewing line, it makes room for the thread and itt finishes the block at the right size.

Thank you everyone. I have checked and double checked by sewing the three pieces together and they come out right on but when I move on to begin the blocks it never fails there is always areas where it is right on then others short while others a tad over.....maybe I am being anal...but I sew just want to get a perfect block! I was wondering if turning a piece would make a difference? I mean if you cut a bunch squares on grain would it matter when you sewed them together and if the squares were turned? Could that make the difference? I have a Babylock Espire sewing machine. I will try moving the needle over a tad...not sure how to do that but will give it a shot today when I get to my sewing room. I love getting feedback from all of you, this board is fun and educating! Thanks

Also once you have stitched.... carefully set your stitches & press your piece with an up down motion, trying not to stretch it. If your block is the correct size in some places, maybe you are veering off the 1/4" at the end of the seam..... ( I really have to work on this one).....