Ok........ so my lovely nan has very kindly given me her 66k manual sewing machine which is adorable.
I found the instructions online and have wound the bobbin , reaplaced the bobbin and threaded the needle , caught the thread etc etc
( I had it working perfectly)
Today i changed thread in exactly the same way as before and my stitches are turning out like this , ive checked the manual but its very old and hard to work out in some places , so I was wondering if anybody has any clues or owns a 66k that could help me.
The underside of the stitch is turning out like this .......

The top looks like normal .
Any help would make this one peeved / confused girl happy