I’m knitting a sweater and have to knit the sleeves in the round on DPNs. I’ve started off with 63 stitches that I have spread over three needles (21 on each) however I have to increase over the length of the sleeve to 107 stitches (an increase of 44 stitches). How do I spread those additional stitches over the three needles as the increase will be at the same two points each time (i.e. along the sleeve seam)?
If you have an extra dpn you can add that as another needle (4 needles with sts and the 5th as the working needle) because 107 sts will be too many for 3 needles. Of course, unless there are stitch pattern constraints you can always shift the sts around on the needles. Sometimes this is even recommended to avoid ladders.
If you have a 9" or 16" needle that could be used at any time.
Remember it’s not critical that stitches be distributed exactly evenly between all the needles. As long as you keep track of any pplaces in the round you need to with stitch markers or some other means, and as long as you don’t have more than half the stitches on any one of the three needles it really doesn’t matter. I frequently just eyeball it at best, unless I’m doing something where I want to use the needle change points to keep track of the pattern (eg sock shaping perhaps).