I'm sewing velcro on to my not to heavey material...thead is buckling up & ; then the needle is stuck

SOURCE: janoneDc3018 thread bunches up .

Are you using heavy thread for the top stitching? If so you will need to tighten the top tension. You would think if it is thicker thread that you would need to loosen the top tension but you have to tighten it to help pull it up through the fabric. If you use heavy thread in the bobbin you would have to loosen the bobbin tension. Check and make sure the thread is seated in the top tension and make sure there is no lint in the tension disc. It is definitely a tension issue. Hope this helps.

SOURCE: My problem is the thread off the needle goes down

check the machine for proper threading, this can cause issues.

SOURCE: bird nest when trying to sew. Under material by

i think you have something catch on the tension guides. Try to clean out anything you can see and pull a thread towards the needle. I have done this with a small knot to snare anything but be gentle. Also, rethread carefully.
Try cleaning the bobbin case too

SOURCE: The first needle thread keeps breaking as it is

could the tension be adjusted to tightly
is thread feeding off cone/spool freely
also check to see if there are any burrs on the loopers or on the throat plate
here's a tip I learned from a needle & thread expert about needle & thread compatability

Cut 6-8 inch piece of thread of the spool you are going to use for your project
Take the needle you are going to use for the project
& insert the thread thru the eye of the needle
& lift one end of the thread to a 45 degree angle
& if the needle is the right size for the thread it will slide down the thread
But if the needle hangs on the thread you need one size larger needle for the thread
Happy Sewing

SOURCE: right hand needle comes un threaded. sews fine for

Many times you can get a small burr on the tip of the lower looper and it will break one of the needle threads. Run your finger nail off the tip of the lower looper, all around, and check for a snag as your finger nail slides off the tip of the looper. You can get some very fine sand paper 600 grit and gently rub on the back side, top, and bottom tip of the looper. Never the front side of the looper. Try serging again and see of that doesn't help.