Accuracy, Repeatability

[bohica]

I just finished 4 identical parts on my IH CNC and thought I would share the measurements I took on these parts. To me, it's quite impressive.

They are 1/2" 6061T6, designed to be 4.25" long and .640 wide. The following are the measurements of the width on each end and the length of the part.

Part1
.64005
.64085
4.2505

Part2
.64060
.64065
4.2510

Part3
.63990
.63970
4.2510

Part4
.64175
.64150
4.2510

Part4 seemed to be viabrating on the final cut so that may explain why this one was off more than the others. Ignoring Part4, the average deviation from design on width is +.0004, and on length is +.0083. Close enough for government work.

[wildwestpat]

Mightly impressed that you can measure to five decimal places of an inch as this is normally the preserve of the clean room inspectors.

Regards

Pat

[bohica]

My digital micrometer reads to .00005. The last digit should obviously be disregarded. I did check this mike against a guage block and it did read spot on.