VMC Accuracy

[jimgarner]

For their toolroom mills Haas states an accuracy for Positioning and Repeatabilty of 0.0004/0.0002. For their VF-1, 2 and 3 machines they state an accuracy of 0.0002/0.0001.

Does anyone understand the reason for this difference in stated accuracy and, in actual practice, has anyone with experience on both machines ever detected a difference in the accuracy of work produced between the two classes of machines?

Thanks,

Jim

[gizmo_454]

I'm not sure on the question that you specifically asked. I know that our Mini Mill regularly holds +/-0.00025 while circular interpolating a counter bore on one of the parts we make. Generally speaking, if the work is held rigidly, and consistently, the machine will repeat extremely close to what they claim.

In our case, we tend to run small parts, so there is not a lot of weight on the table. From what I understand, though, those tolerances they claim are with an empty table. Someone please correct me if I am wrong in that assumption.

[AMCTony]

I have been able to produce small parts on my TM-1 with +/-0.0002 without too much trouble.

[jimgarner]

Thanks for your input.

It would be interesting to see a part made on a TL-1 compared with an identical part made with the same program on a VF-1. I wonder if the VF-1 version would be closer to spec. than the TL-1? I would guess that for a small part it would be about the same, but a very heavy one might show a difference.

Jim