Problem with Techno LC Series 4896

[Dirty Jerry]

Hoping this is the appropriate forum to post this under, there's so many! Alright, I'm having a bit of a problem with our router and would really appreciate any suggestions or ideas as to what may be wrong. Again, working at a sign shop here. Cutting Pionite Melamine to make "sand carved" signs with 1/32" raised text. The machine was run for nearly 6 months without greasing (ouch) prior to me learning to operate it and begin proper maintenance on it and we ended up replacing the entire corkscrew underneath the machine because it was getting pretty jerky (expensive much?). Since then the signs have not been coming out quite the same. I can cut the same sign twice side by side and they will be different.. the letters will have nicks in different places and circles are no longer perfect circles.. (mostly cutting 1" high letters). The owners would like to believe that it is not a mechanical issue but I'm not convinced. How come the signs came out flawless a year ago, yet using the same exact methods to create signs now, they are hideous? We have tried changing nearly everything to appease them and keep production moving (cutting Climb instead of Conventional, etc..) which has improved the quality very minimally. I have tried to point out to them that when its making the fine movements of cutting small letters I can physically feel the machine jolt slightly (by putting my hand on edge of table). The machine is leveled well. My question to you then my dear educated CNC operators (I'm a newb!), is what part might need replacing? Part of the Y-Axis? The spindle? I'm sure whatever it is they aren't going to be happy, but I'm sure they'll be much LESS happy to lose all the business we have in sand carved signs. Please help!

[charlesparise]

First question would be are you sure the screw drive used is the same one, threads per inch? It seems that if the machine is not cutting circles but elipses this could be the problem. Also, you can go to Techno's site to see the maintenance that needs to be done, the z and y also need to be oiled every so often , I use a small brush with a light oil to get those axes lubed. The THK bearings I hit with a couple pumps from a grease gun. Try cutting a 24 x 24 box and check the measurements.