Feeding fabric in machine - ends up curved
 

I have a Necchi Ex60 that is about 2 mos old. I was at class the other night and noticed that when I sewed narrower, longer pieces together (2.5in x 42in), and held it up, the pieces curved (towards the right). Last night, I fed in some fabric and let the machine pull it by itself. It would start off straight but inevitably would always curve to the right. I tried messing with the presser foot tension but that didn't seem to help.
Does anyone have any ideas? Is this common or should I take it to the shop?

Try sewing with your walking foot. This way the fabrics feed evenly and won't be distorted when sewing a long strip.

Are you sure the fabric itself isn't curved? If you don't match up the grain before cutting long strips, it will bow in the middle. Hold up a strip and see if it's truly straight.
Just a thought.
Watson

You can add a guide to your machine table at the 1/4" distance. Some people use moleskin patches, others use a note pad (tape it down with blue tape). That way you can guide the strips along the ridge.

It's important to cut fabric straight on the grain, if not you will get a curve, also if sewing 3 strips together, sew the first two in one direction, the join your third and sew in the opposite direction.

Strip sets will get the curve even with the best of sewing, it's the nature of it.

Most machines are going to veer slightly towards the end of a strip, you really have to keep control of the strip with your hand, some feet and machines are a little better at sewing straight than others. I can honestly attest that my big expensive machine did not sew as straight as some of my smaller machines until I switched feet and attachments and now it sews the best straight seam I have ever sewn so many things play into straight sewing.

I agree. I often sew long strips (just to get a quilt done, and still look ok). I have sewn in opposite directions, cut length of fabric (works a little better), straightened with ruler, etc. Sometime it works, sometimes not.

It is what it is.

If you sew a couple of pieces of fabric together (not strips) without guiding with your hands, you get the curve? If so, this usually means that the feed dogs are not aligned correctly. If they are off by a few degrees, the machine will sew a curve rather than a straight line. My Bernina will sew a straight line even if my hands do not guide the fabric.

Since your machine is only a couple of months old, it is still under warranty. I would take a sample of the sewing and the machine back to where you bought it and ask them to correct the problem. When you pick up the machine, bring some fabric with you and do a test sew to make sure that they actually corrected the problem; you don't want to get the machine all the way home only to discover that the machine still does the same thing.

If the machine sews a straight line on fabric but your thin strips still end up curved, this indicates that the presser foot pressure might be too tight. Some machines allow you to adjust presser foot pressure; check your manual. If the pressure is too high, the foot is pressing on the fabric edges so tightly the edges are stretching as they are sewn. This results in a curved strip after sewing.

In general, high quality machines will come out of the factory with well-aligned feed dogs and presser foot pressure correct. I am not an expert but, in my limited experience, Necchi is not a great brand anymore. Vintage Necchi's are collector's items, but I'm afraid the Necchi brand has gone much the way of the Singer brand in terms of quality in sewing machines. It's not only the way they come out of the factory, either. It's also in how they hold their adjustments. You may want to look into "trading up" at your dealership into a brand that has a better reputation for quality.