wow. Level shifts. Massive ones at that.
First thing you'd have to suspect is motor skipping or the GT2 belt springing over a tooth of the pulley.
On a Wanhao (Prusa Clone), stuff you can check is :
1) pulley's still fastened ? The are fixated with a small imbus/allen key on the axis motors. When this allen key comes loose, all kind of horrors start happening.
2) belt tension problem
3) on some Wanhaos I know the Melzi board/stepper controller there are sometimes notoriously off-spec.
4) printspeed WAY to high ?
5) do the axis of the carriage run freely ? Nothing that obstructs the movement ?
But with such massive issues, the problem is mechanical most of the time. Also, I've been told by a couple of friends who have a Wanhao that although they love their printers and I agree they're excellent value for money, their quality control -especially on the cheper models- is lacking. Like, A LOT.
Wanhao has an insanely active user forum. They are your first and foremost treasurechest in terms problem solving. Wanhao has a large following of near-fanatical users, do yourself a favor and put your problems up there too. It would not be the first time Wanhao would have a series of machines where they forgot X or botched up Y, and where near impossible problems turned out to have very easy solutions.
Keep us posted, and success !
