prints turn out with rugged edges

I built my reprap and calibrated it all but when ever I print something it will shift over the bigger the print the more it shifts and it usely shifts once and then will biuld from thier but after that the edges turn out bumpy like it is slightly shifty then going back I've looked for the belts sliping and they don't seem to be I've been missing with the current to the stepper motor current to see if that's it and I can make it worse but I can't seem to make it better

Big shifts are normally skipping steps, turn up your stepper current on the axis its slipping on a fraction (1/8 a turn), or reduce friction (make sure things are alighted correctly and lubricated)

Small positioning errors are quite often the hot end not ridged on the extruder.
While its off and cold grab the hot end, make sure its solid with the extruder.

But im only guessing, you should really post a image with questions like this..

Ok thanks the hotend is loose in it so I will try to secure that but I slowed it down and that helped a lot probably because its not wobbling has much and for some reason it won't let me post pictures

There's a really small size limit on pictures..

Good software can make a fairly large image a very small file size. As an example the attached image is just under 50kb.

Edited 1 time(s). Last edit at 04/24/2014 04:42PM by tmorris9.

Ok thanks I will try to post some pictures later today I'm busy right now

I've always been too lazy and just make GIFs with MS Paint.

I had a similar problem with my machine, but would occasionally see a huge shift in my prints (several millimeters). This first thing I did was slowed the travel speed down which did help but in hindsight it was only a band aid to the real problem. After further troubleshooting I realized my x axis was binding but only slightly (it felt a little jerky when sliding by hand). When you consider the rapid acceleration and sudden direction changes it doesn't take much binding to loose steps. This root cause ended being a bad spot(s) in my timing belt. To solve, I simply flipped the belt so that the bad spot was on the idler end of the x axis. No problems since.

I think if the belt were slipping you would notice a huge shift in your prints like I was.

In my opinion your problem probably isn't lost step or slippage but rather a repeatabilty issue. I would check is belt tension. A loose belt will allow for more backlash (and vibrations) and effect your machine's repeatability.

The Problem was the hotend wasn't secure so I fixed that the lines on the x axis are smooth going up but the y axis still goes one way so I started to mess with the current Agian on it and it then started to go the other direction so I just need to spend some time adjusting the current I'm planning on switching the wiring around to make the motor go the other way so it should make it start shifting the other direction if it really is the current if it doesn't then it should be the belt alignment or tension