Hi, newbie question i guess.
We are looking at buying a prototyping/low volume production vmc at around £40k (60k$). Mainly for working aluminium and plastics.
We have had samples cut on different machines from different manufacturers.
The samples have vertical ridges/lines in the side walls. These are visible on interpolated internal and external circular surfaces, and to a lesser extent on straight x and y axis cuts.
On some samples these are visual, an on others they can be felt with a fingernail as well.
The three attached images show this. The images of the metal parts are taken from elsewhere in this forum, but illustrate the effect. the plastic part is one of the sample pieces we have done, note the ridges on the flat as well as the curved surfaces (ignore the dust!)(scale on left is mm).
What causes this? servo step? ball screw pitch? backlash?
Is this typical for this level of machine?
Is it usually possible to tune it out/reduce it?
Thanks.