Timing belts keep messing up head movement

[Wolfman21]

I had the 3d printer working, and it printed just fine. Then one day my stupid self, tried to remove a strand of filament that was sticking out while it was printing and the head bumped into me and ruined the print. I tried moving the wheel at the top down, then retightening the belts, and moving the wheel back up to gain tension again on all three tower arms. This should have fixed it, but everytime I print anything, the Z-axis comes loose or is too tight to function properly and it doesn't move down with the other arms.

So....

I replaced the carriage and I was able to print a small box perfectly, yay! But when I print anything else, the arms will go down and the Z and Y axis will come loose or something and ruin the print. I've tried tightening the belts, and raised the wheel at the top for extra tension, I've also tried loosening it little by little to try to find the perfect tension, but nothing works.

ANY SUGGESTIONS??? THANKS..

[Tincho85]

Remove the belts and check your pulleys and bearings, maybe there is something blocking it.