Hi, I am new to sewing and I have a singer machine, if I roll it manually it stitches fine but as soon as I start pushing the pedal the stitches don't connect anymore, I've changed the tensions and I think the timing is okay since it stitches fine if I use the wheel to stitch. I am using a cotton poly fabric, dual duty thread, I've tried 3 needles and different fabric just in case but nothing is working. Any ideas? It has a verticle bobbin case which I think I loaded correctly (but directions on this would be helpful) and is driven by a sprocket assembly not a belt. I've rethreaded the machine a few times and I'm sure it's right (at least the top thread is) I have all the fabric cut to make my very first dress for my 2 year old and I can't figure it out!! Please help!!