Well let me try to break it down for you... Most nationally know teachers will tell you that a scant quarter inch is moving the needle to the right by one click. Great, that is if you have a machine that moves the needle for you or that you can move the needle... but even if you do, your machine may not be able to move '1' click. Maybe it is an older model that when you move your needle, it moves it all the way to the right or all the way to the left (my old singer did that, only 3 needle positions) Now I have a machine that has a 7mm swing in the way the needle moves, it is only 5 years old and it is out of date with the amount that you can move your needle....
So what is a quilter to do?
They say to use a quarter inch foot and a single needle throat plate. Ok, so let's change the throat plate on my machine. Not an easy task. One has to remove the surrounding cover that covers the bobbin area. Then remove the presser foot and the attaching ankle. IF you really don't want to get stabbed in this process, you take out the needle as well. After that is all done, you take out the two screws that are holding the plate in place (the larger holes in the picture)only AFTER you find the little stubby screw driver because you only have 2 inches of clearance to get to these screws!
Once you do that, you discover that you need to clean the bobbin area, so one takes out the bobbin, the bobbin race and then starts to clean the hook area. Why stop there, go for it and remove the rest of the bed area and give it a good cleaning there as well. DO NOT use canned air.. (reasons are listed in a prior blog) Ok, now that you have that all clean, you put it all back together, bed pieces, bobbin race, single needle throat plate and those pesky little 1/4 screws with that 2 inch screw driver, foot ankle, foot, NEW needle (good a time as any to put in a new needle) replace the surrounding bobbin cover, replace the bobbin. Whew!
Get out a scrap of fabric to make sure everything is working right, turn back on the machine, go to adjust it to the scant quarter inch.... and the machine won't move the needle!!! Well crud! Get out the book and after reading for 1/2 hour, find that with the single needle throat plate on the machine, the machine has a safety that will not let you move the needle so it can only sew in the center position! All that work for #(%&^$( nothing!
So I decide to work with what I am given. I do a test strip and find that with the 1/4 inch foot on and the needle in the center position, the needle is just slightly to the left of the opening in the foot. Curious, isn't is supposed to be dead center in the foot? Yeah that is what I thought too. So do a test seam. I measure with my trusty 1/4 gauge and a couple of more rulers. I find that the edge of the fabric is on the quarter inch mark, and the stitching butts up to the edge of the ruler. IF I was a betting woman, I would say that is a 1/4+ seam. So not to second guess the high and mighty sewing machine companies, I make a block using the edge of the foot as a guide. Turned out perfect, then I measured it. These are FW blocks, unfinished are supposed to be 6 1/2 inches. This blocks measures a perfect 6 1/4 inches! (one on the left)
Now I am really ticked! I go through the whole procedure to put back on the zig-zag throat plate minus the cleaning, move my needle to the right by 1 click (which on my machine is 4.5 mm (4.0 being center) remake the block and it measures a perfect 6 1/2 inches!
1 click, same foot, now the needle is in the middle of the foot.
Because each seam now is being sewn 2 threads to the right of center... a scant quarter inch.
In the picture to the right is a piece of RJR fabric. The blue line is 1/4 inch and there are 16 threads in that 1/4 inch.
If you look at the block, there are 4 seams, 2 fabrics in each seam, for a total of 8 places to make an adjustment. Uh Oh, I just saw math pop in your head!
4 seams x 2 fabrics each = 8 sides
8 sides x 2 threads each = 16 threads
16 threads = 1/4 inch
2 threads = Scant Quarter Inch
So now that we have solved that mystery and the machine is clean... Here are Blocks 71-70 of class # 7 of The Farmers Wife Revival Quilt.