I analyzed the structure in ANSYS. Results are better and more hopeful but the question remains: What is the preferred (acceptable) range for frequencies and relevant deformation in CNC machines like the one that i am going to build? Any suggestions? Thanks.
Click image for larger version. 

Name:	M1-T.jpg 
Views:	214 
Size:	73.8 KB 
ID:	12382Click image for larger version. 

Name:	M1-X.jpg 
Views:	211 
Size:	82.6 KB 
ID:	12383Click image for larger version. 

Name:	M1-Y.jpg 
Views:	220 
Size:	77.9 KB 
ID:	12384Click image for larger version. 

Name:	M1-Z.jpg 
Views:	213 
Size:	78.3 KB 
ID:	12385Click image for larger version. 

Name:	M2-X.jpg 
Views:	205 
Size:	82.5 KB 
ID:	12386Click image for larger version. 

Name:	M2-Y.jpg 
Views:	208 
Size:	80.8 KB 
ID:	12387Click image for larger version. 

Name:	M2-Z.jpg 
Views:	234 
Size:	75.4 KB 
ID:	12388