pocket problem .. with pictures

[ncave66]

Ive been having alot of fun with cut2d and my machine but have these consistent vertical lines at the bottom of my pockets. Did a couple of quick test cuts to illustrate whats going on. I normally pocket 1.5mm and ramp in over 5ish mm with a single pass at 20ipm. safe z at 2-4 mm above depending on the cut. Raster, climb, 90degrees, profile pass last. I can sand them out, but shouldnt have too.....and no space invader or trees were hurt during these cuts

[Rcnewcomb]

It looks like:
1. Your spindle may not be plumb. (Look at instructions for how to tram your spindle)
and/or
2. There may be some play or roughness in movement of the Z axis (check for something loose or binding)

[maineshops]

End play in your spindle? Too much stepover?

[PaulRowntree]

It can't be a coincidence that the lines on the rhs start with protrusions on the tree. What is the toolpath doing there? Z backlash would be my bet.

[ncave66]

Thanks for the replies and taking a look at the pictures. So I did go ahead and tear down the y and z gantry after finding flex when I pushed on the bit. I found a couple problems and am ordering parts to correct binding in the Y and support the z unit (flex in the direction of x).
The third thing i am about to look at is why the Z is so very stiff to turn with my fingers. Been like that since I bought it as an assembly and being new to this wrote it off as normal because I feel no backlash etc. I'll try to get a couple pictures of the Z tonight. Thanks again, Tim

[ncave66]

Saw too much stepover was mentioned....What are the consequences of too much. I find I need to go 9 or 10 to get the bottom smooth (aside from what Ive posted in the above pictures). Asking not because I doubt you, but because I dont know.