Keeping a spiral "true".
 

I am currently quilting a large spiral with my walking foot...it is about 42" in diameter at present and has another 12" or so to go. I have noticed that it is getting a little bit "out of true" obviously from my not being super accurate following the spiral with the walking foot. It's not very obvious but I was not wanting it to get any worse so is there a way to remedy this? If it was circles I could just measure the radius from the centre and draw where my next circle should be and follow that but as it is a spiral I'm not sure if it would work the same way? Any ideas or tricks? My friend says to just not worry about it, that when it is all finished any little wobblies won't be so obvious. Opinions please?

Can you upload a picture? I'm thinking some stitch in the ditch or additional basting, but I'm not sure I am visualizing your quilt.

I assume you started in the center of your quilt? I agree that some wobbliness won't matter. However, if you really want to start compensating a bit for the "out of true", what I would do I use white chalk (or white soap) to measure out from the center to a little beyond your last quilting line. You can use a string to mark a circle or, if it's easier you can just mark a square. Mark again a few inches beyond that, and again all the way to the edge of the quilt. These would not be quilting lines for you to follow. Rather, they will be marked guidelines so you can gradually compensate for the lines you have already done. For example, if you find your last quilting line is close to a mark on one side but far away from another side, you can quilt a little closer to your last line or a little farther away from your last line to start making up the difference.

Hope this is clearer than mud.

Yes Prism99 I did start from the centre of the quilt. Your suggestion makes good sense... I will have a "go" at doing as you suggest. Many thanks.