Strange fault, Wanhao duplicator 3

Not used the printer for a couple of weeks and it seems that whatever I print it is getting stuck. It does the outer perimeter OK then starts doing the first layer but after about 10 passes it gets stuck, it is not stopping but going over and over the same line apparently for ever. It took about 10 minutes to register that the sounds from the printer were not changing and this is what it had printed.

Tried a different STL and the same thing but it does seems that existing X3G files are printing OK. This is not something I have ever seen before.

More investigation required, has anyone else seen one do this?

http://i.imgur.com/yp0vvOz.jpg

Video of it being stuck, most weird.

http://homepage.ntlworld.com/dknpowe...919_085932.mp4

:eek: I found it I think.

There is a setting in Cura for extra width on the bottom layer. It recommends making this 50 meaning a line width of 150% on the bottom layer. I don't want extra width on the bottom layer so I have this set to 2. It appears in red adn warns you that 50 is recommended but it has always worked. For some reason all of a sudden it is making the line width 2% instead of 102% so it appears stationary, if I leave it a long long time it will eventually work right and print the item.

I have no idea why it has started doing that, it used to work fine and I haven't updated anything.