Why is bobbin tread jamming on my husqvarna viking juliett sewing machine

SOURCE: Threading a husqvarna viking 3610

This should be your machine:

http://www.sewingmanuals.com/Viking_Pics/Viking_3610i1.jpg

Sewingmanuals.com shows that they have this downloadable in Adobe PDF format here:

http://www.sewingmanuals.com/Sewing_Machine_Manuals/Viking.htm

#37 in the list as of me posting this. You can get a CD version too but you'll just pay more and wait longer for the same thing. Once you have it print the manual (preferably both sides to keep it small) ang you'll have it. You can also peruse eBay to see if anyone is selling a manual but I doubt that will yield regular results. The machine looks to be pretty basic and standard but it's best you have the manual to get the most out of the machine. Also be sure to check the cleaning and lubrication section and go through the process so that the machine is in top working order before you put it into regular use - saves a lot of headaches.

SOURCE: Singer CG 550 Top thread keeps wraping around the bobbin and jam

Have you checked the top thread is correctly placed in the spring of the bobbin case?

SOURCE: husqvarna sewing machine - viking 400

Take to authorized Husqvarna Viking dealer for repair. This is not something that can be done by the owner. Check Husqvarna Viking website for dealer closest too you.

SOURCE: Sewing thick fabric and machine won't send it through

Sergers are not really meant to sew very thick material. The blades have a maximum amount of range, or thickness that they can reach to cut. If you go outside that range, get ready for a big repair bill! You can break loopers and even the needle plate when you "push" a serger. My advise would be to use you sewing machine for the, "pounding" work. The type of material matters too, A thick Quilt like fabric can be sewn becatuse it's not dense material. A thinner harder denim could max out at 3 layers because of it"s hard finish. If the fabric you're sewing isn't dense like, you could just need new knives.

SOURCE: viking husqvarna classica 100, thread tension

I suspect you are correctly threading the machine but the timing of the needle and bobbin hook is off. When the threaded needle goes into the bobbin area, a pointed hook grabs the thread and loops it with the bobbin thread. Something is catching when the needle starts to come up that is not allowing the bobbin thread to be pulled back through the needle plate opening by the upper thread. With machine threaded and bobbin in place, have the bobbin area open if possible and watch the thread interaction when the needle goes down. To set the hook/needle timing, normally covers have to be removed. Suggest taking it to an authorized Husqvarna Viking dealer for service. You can find the nearest dealer by click on the "Dealer" link at http://www.husqvarnaviking.com
Good luck.