Tye of needles

Remove the top thread from the machine.
ALWAYS RAISE the presser foot and rethread the top thread.
Test straight stitch.

For fraying thread, there is either a burr somewhere in the thread path or the needle is not correct for the thread. Sometimes the needle eye is too small for the thread and causes the thread to shred. Changing the type of needle (an embroidery needle, top stitch...) may help. Certain brand name threads work better or worse on certain machines. You might try changing thread brands. Avoid old or bargain bin threads.

All About Needles SCHMETZ Needles

Sewing Machine Needle Troubleshooting Guide SCHMETZ Needles

Your owner's manual should tell you what type needles your machine uses. According to this site, 130/705 needles will work with your machine, are also very common, and are available in several brands: Schmetz, Janome, Organ, etc.

http://www.sewingpartsonline.com/necchi-6018-sewing-machine-parts.aspx

In addition, you will need to determine the needle sizes (60/8 through 120/19) as well as the needle point (universal, ball-point, sharp/microtex, top stitch, embroidery, leather...) so the needle is compatible with the thread and fabric you are stitching.

SCHMETZ Household Needle Chart

Be sure to change the needles frequently. A needle should be replaced about every 8 hours of sewing time. Sewists tend to skimp in this regard (although needles are the least expensive fix!), but the needle is the most frequent cause of sewing machine issues. So, if your machine begins to misbehave, the first thing to try is a brand new needle.

...

https://www.manualowl.com/p/Pfaff/hobbylock-774/Manual/184560

try these link for parts and needles

Kenmore Parts


Sears com


http://sdroasklr.mystarship.com/lacie/kenmo330.html

What type of material are you going to be sewing? Sew-Classic has 10 needle packages of the size 12 and size 14 needles for the Singer 306 for light (not fine) and medium weight material. (It's a 206x13 needle for the single needle. The twin needle is a 306x3.) See http://shop.sew-classic.com/206x13-Sewing-Machine-Needles_c46.htm .

http://www.allbrands.com/products/15221-schmetz-german-206x13-flat-shank-needles-100-size has some notes on alternative needles. The site has boxes of 100 size 14 and size 12 needles. (The size 14 needles are out of stock due to delays on the manufacturer's side.) https://www.college-sewing.co.uk/206X13-SIZE-90-PACK-OF-10-NEEDLES (size 14) needles in stock.

Unfortunately, I do not see any twin needles available for the 306K. I hope this helps.

Cindy Wells

Try some Schmetz brand needles, they skip less than any other brand. If that does not solve the problem, you need to have it serviced.

Theirs a problem with the fuse on those machines. The e1 indicates that a fuse has been blown. check out the link for more details.
http://www.sewingmachineryrepair.com/forums/index.php?topic=79.0

On my machine I find that my bottom and top free motion stitches are more uniform when I set my needle thread tension at 8 or 9. Also, you might want to use a top stitch needle.

Good luck,
SewReady

You should use a blue needle or a ball point needle for when sewing knits or synthetic fabrics.

THe 19233 has only one size mongramming built into the machine. It has a 5mm' length and 7mm'' width therefore the complete needle range of this machine is just under 8mm and can not be adjusted