Necchi nova My cotton keeps on snapping. what can the problem be

If you have the old bobbin case, take it and the make/model to the local sewing repair shop. They will either have one in stock or can order one for you.

Search the internet for:
Manufacturer + Model + the word "Manual"

or search YouTube videos for "sewing machine threading." You may not find your exact machine, but many machines have similar threading patterns. Be sure to raise the presser foot before threading the upper thread so it will seat properly in the tension disk.

If the thread is breaking at the needle, it could be several problems:
Threaded incorrectly--#1 cause
Upper tension too tight
Install a brand new needle compatible with the fabric & thread
Make sure the thread is not too large for the needle eye
Avoid old, fuzzy, bargain bin thread

All About Needles

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I suggest having the machine checked to see what the problem is with the hand wheel

Your hook is moving correctly. Not all machines do a continuous circle. If it's not catching the thread, the timing is off. It's a great machine, and worth every penny to have it serviced.

Try http://www.sewingstyle.com/Necchi-Sewing-Needle-Plates.html - the BU Nova is a 50's era machine so you may have to hunt down a second hand spare part or see if one of the other model plates will fit this model.

Also there are 3 or 4 Necchi Italian machine owner groups on Yahoo, I'd suggest that you join the one called Necchisewingmachineclub and then check out any posts on spare parts and see what you can glean there. Just read the group rules as often they like members to "share" information and don't like newbies to drop in and post a question then disappear. Or ask the same question on several groups (crossposting).

I know that many Super Nova owners love their machines and highly regard them.

Good luck tracking down the part for yours.

between $40. & $60 with cabinet and accesories

It is quite common for some sparks to be seen in the armature but id it is excessive you may need to replace the carbon brushes if you can get them

http://www.sewingstyle.com/Necchi-Sewing-Manuals.html

You can also use a Eureka vacuum cleaner belt, can't remember the exact model, but the package says it's for most sewing machines. It's not the V belt, but it works on my Super Nova and it's 1.79 for two!

Just pull down on the original metal foot. It will snap off and then you can snap on the button hole foot. Good luck!

Trudy