Christopher
Aluminum
- Joined
- Jun 3, 2006
- Location
- Gainesville, Georgia
Howdy all,
We are running a Fadal VMC40 (aka 2216) and have a feature that is bored to a shoulder. The bore is 1.851" diameter and roughed out with a 1.75" Ingersoll "quad drill", then finished with a pair of boring operations (roughing/finishing); the last 0.007-9" diameter with a Criterion "tenthset" head. I am getting varying depths on the bore, to the tune of 0.010"!!! I assume our machine has bad thrust bearings on the Z, but the ball screw may be partially to blame as well. As a newcomer to the world of "NC" machinery, I have considered using a screw jack and thick rubber matting, to CAREFULLY apply measurable upward load on the Z axis and measure the change. Do any of you more experienced folks have any thoughts on this? It seems impractical to try and separate ball screw wear from thrust bearing wear; with my rudimentary method, and I am not sure if there is a way to do this without taking the ball screw out. Thankfully, the depth variation is not a closely held value on the job; however, the variation in depth IS causing the finishing tool to work harder at the bottom of the holes than desirable for maintaining the bore diameter values needed!!! I also hear a noticeable "bump" in the Z axis during peck drilling operation that have moderate load; this does not make me feel like everything is at "factory tolerances". Any insight from the PM community would be coveted!
Best regards,
Christopher
We are running a Fadal VMC40 (aka 2216) and have a feature that is bored to a shoulder. The bore is 1.851" diameter and roughed out with a 1.75" Ingersoll "quad drill", then finished with a pair of boring operations (roughing/finishing); the last 0.007-9" diameter with a Criterion "tenthset" head. I am getting varying depths on the bore, to the tune of 0.010"!!! I assume our machine has bad thrust bearings on the Z, but the ball screw may be partially to blame as well. As a newcomer to the world of "NC" machinery, I have considered using a screw jack and thick rubber matting, to CAREFULLY apply measurable upward load on the Z axis and measure the change. Do any of you more experienced folks have any thoughts on this? It seems impractical to try and separate ball screw wear from thrust bearing wear; with my rudimentary method, and I am not sure if there is a way to do this without taking the ball screw out. Thankfully, the depth variation is not a closely held value on the job; however, the variation in depth IS causing the finishing tool to work harder at the bottom of the holes than desirable for maintaining the bore diameter values needed!!! I also hear a noticeable "bump" in the Z axis during peck drilling operation that have moderate load; this does not make me feel like everything is at "factory tolerances". Any insight from the PM community would be coveted!
Best regards,
Christopher