Weird alignment at end of print

[GamerDarling]

Hey guys, I got my printer last night! Woot! I did my first print, and was silly and did a 3 hour one before going to bed. For the most part I had some minor warping issues so I installed the door and everything else was great....right until the end. https://www.dropbox.com/s/priud8tsob..._0088.JPG?dl=0

Any ideas as to what happened, and what I should change?

Default settings on everything, straight out of the box printing ABS(let me know if you need more details)

[GamerDarling]

Ok, so I just tried another print and got the same issue, but much earlier in the print, and in a way that clearly isn't a warping problem. It's gotta be something with whatever is controlling the x/y alignment. https://drive.google.com/file/d/0B0n...ew?usp=sharing

[jfkansas]

Ok, so I just tried another print and got the same issue, but much earlier in the print, and in a way that clearly isn't a warping problem. It's gotta be something with whatever is controlling the x/y alignment. https://drive.google.com/file/d/0B0n...ew?usp=sharing

Probably just have a pulley slipping on one of the shafts. Threadlock and tighten all set screws on the pulleys.

[GamerDarling]

Thank you so much for trying to help, and please pardon my confusion, I'm totally new to fixing mechanical things. So I'll probably have some strangely basic questions...

There were some screws that the manual wanted me to tighten, and I think those are the ones you're talking about, but I couldn't find them based on the manuals pic. Here's a picture the manual gave me of what to tighten for one of the pulleys: http://screencast.com/t/WeaH8iFB0N . Images 90,91 and 92 in this folder are what that pulley looks like on my machine.
https://www.dropbox.com/sh/5jyw064is...afBxDTlaa?dl=0

Are you(/the manual) referring to the screws in image 90? Or am I looking at entirely the wrong spot?

Again, thank you! Really appreciate the time!

[soofle616]

There is a belt for the x and another for the y axis motion. At the end of each belt there is a pulley. The X axis stepper motor actually has two belts that it drives, one from the motor to n idler pulley, and another from there to the carriage. Follow the belts until you get to a pulley on each end. Spin it by hand until you see the set screws (there are 2 per pulley). Make sure those screws are tight (blue thread lock is a good idea to prevent loosening due to vibrations). All told iirc you're looking at 6 pulleys which means 12 set screws.

[jfkansas]

Recently Flashforge has changed to nylon pulleys that are keyed to the shafts without set screws. Not sure if all of them are changed though. There are also some pulleys at the top, maybe those are still metal with set screws. If any of them slip it will cause the position shift. It is either that or the belt might have jumped a tooth during a fast move. In that case it just needs to be tightened a little. Belts stretch a little after the first few uses.

[GamerDarling]

Oh good! I'm not totally blind! I tried looking for the ones at the top too, and I didn't see those either(I even took off one of the sides to see if maybe I was looking at the wrong angle)

Do the nylon based pulleys still have that propensity to slip? If that is the problem, and I just tighten the belt will that make it worse, or even potentially break things?

[jfkansas]

They had to have "keyed" the nylon to the shafts some way with a D shape or a pin. On the metal ones pulleys would slip a little on the shafts if the set screws worked loose. If a belt was slipping you would hear it most likely. It would be a popping sound. The thing is if it was slipping it would have done it earlier in the print most likely also. Maybe 2-3 times even and that would have more shifting.

Did the model come loose off the build plate at all toward the end?

[GamerDarling]

On the bulbasaur it happened 3 times, but the pic I had of it hides the other two. They were very minor and they're almost like part of his chin.

On the zelda keys it only happened once because I stopped the print. All three prints seemed to adhere to the platform very well. I had to use a little tool to pry them off. Is there any chance it's a settings issue? Could the speed be too high?

[jfkansas]

Speed can cause a belt to skip because of the weight of the print head. What speed settings are being used?