Overlocking

[Ellabella]

I am about to sew https://sinclairpatterns.com/products/sofia-shawl-collar-classic-sweater-pdf?_pos=1&_sid=fd493386e&_ss=r  out of a very scrumptious sweater knit.

I’ve fired up the O/L and just sewn a test piece.  It’s quite a thick fabric and when I take it out of the machine the seam is quite wavy but it presses flat.

Do I need to alter the differential feed?  I’m worried that the waviness will come back when I wear it but have never needed to touch the differential feed and am scared of messing things up. I had a smashing book that explained everything but I let someone borrow, it never to be seen again

[SewRuthieSews]

sounds like it'd be worth trying the differential feed on a couple of scraps.
I can never remember which way is what, so I just get a few bits of the leftover fabric, whizz it to one extreme, try iy, then the other extreme try it again then pick the least wavy outcome.
I try not to press knits too much as sometimes they dont recover from it

[Ouryve]

Bernie has handy pics on her differential knob. Smaller number to squish, larger to stretch - so you want to turn it down.

[Helen M]

Which overlocker do you have @Ellabella? I'd say you need to turn it up from 1.0 which is normal to maybe 1.5 as you actually want to 'gather' the fabric slightly. Try some scraps though.

[Ellabella]

@Helen M I’ve got a  Babylock Imagine, which is probably why I’ve never had to fiddle with anything.

@Ouryve squishing it is then.

[Ouryve]

And @Helen M is right - the squish direction is a bigger number when you turn it.  :thinking:

[SewRuthieSews]

Bernie has handy pics on her differential knob. Smaller number to squish, larger to stretch - so you want to turn it down.

Funnily enough my Bernina 800DL has exactly the same symbols, but I have the machine to my right with that bit away from me and hadn't remembered they were there!

[Helen M]

My dials are on the front of my ancient Brother @Ouryve, but I always have to look at the symbols to see which way I need to push the dial, even after 30 years!

[Ellabella]

Well it turns out I have similar symbols,   

I had to go to 1.8 and lengthen the stitch to get a good seam and I had to go very steadily when I was sewing over 4 layers of fabric but everything seems fine.

I just need to give the bottom band a final press, after my coffee.

I might even wear it tonight for the pub quiz, it’s very snuggly.

[BrendaP]

If it's coming out wavy you've got too may stitches for the length of fabric, so yes you do need to adjust the differential.

 
I can never remember which way, but the fabric needs to feed through a bit faster.  Jut play with scraps of fabric.

[Stitchalot]

When the differential feed is correct, the seam will lay flat on a table, without being gathered or stretched. Keep testing on scraps. I find most jerseys need some positive diff feed on my machine.