Solved Need help with print issue

I have a printer i built .Its pretty much a Robo R1+ built with R1 parts TR8*8 leadscrews . I cant get it to print right though. Im having a weird shifting issue on some parts .In the pics notice its shifting the print right where the solid base meets the thinner walls . On other parts that are all solid it seems to print ok though. This is not a stl issue. I print tons of these on my other robo. Im using the same slicer settings/file. Any idea on what can be causing this? The belts and all looks ok.

 

Checking the stepper drivers is one thing i havent done but could that be it cuz they seem to be moving fine and other then that one shift it prints fine. Heres some pics of the printer. The firmware is RC6 using mesh and axis steps for TR8*8 leadscrews.Motors are the same Robo motors

 

Also the shift happens right at the same layer everytime i try to print it. Right at the end of the solid base and the walls start printing. One thing i was thinking about was it looks like its only really shifting on the Y axis. The bed is solid, moves freely and belt is tentioned good .The xaxis may have a 16T pulley. It doesnt say which it is on the pulley. If that is the case ,the firmware is set for 80steps/mm when it should be 100steps/mm. Could that cause this problem? Im thinking no because the shift is only in one spot and part is the same diameter all the way up it ? The Y axis for sure has a 20T pulley which is correct.

Do you think the Z axis could make it shift? The rods look pretty straight.

 

Fixed it somehow. Not sure what was the actual problem. I noticed the clamp i have to hold the z rod at the top of the printer was loose on one side allowing one z rod to move some so i tightened that . I also took the Y pulley off to check how many teeth it was and put it back on and retentioned the belt. I also lowered the outline print speed and x/y travel moves in simplify3d and resliced it. Not sure which of those 3 things fixed it but its working great now.