You guys will like this one.
So we are trying to establish the best way to measure TOTAL INDICATED RUNOUT. TIR.
We have a 15X22X10 GLOBAL S with a HPSX1 2.5° indexing head and a 5mm x 50mm tip (standard ruby)
We also have a MCMASTER CARR ordered 12'' long Ø1.5 steel bar. Accuracy of this bar isn't terribly critical although I think MMC guarantees less than .001'' over 12''.
We are going to be making parts in our shop sometimes with .0002 TIR and equally tight diameter tolerances.
I have created a basic test to see how accurately and repeatable this machine is.
STEP1: measure the shaft at 0,0 to establish cylinder
STEP 2: at 90,180 measure 1'' of Yminus end using 2 different POINT DENSITY's. 1. @ 6pnt/mm 2 @ 10pnt/mm SCAN SPEED IS 5MM / ACCEL IS 5MM FOR BOTH SETS
(ADAPTIVE CYLINDER CONCENTRIC CIRCLE SCAN)
STEP 3: rinse repeat on Yplus using 90,0
STEP 4: Paste Pattern 10x
STEP 5: REPORT TIR from ymin CYL to yplu CYL for each corresponding speed. For clarity, I am reporting YPLU to YMIN TIR, so i'm just checking end to end)
results are that the lower point density is netting better results by about .0002 (ex 6pnt = TIR .00064 10pnt= TIR .00088)
diameters measure within .0001 each side with both speeds.
THOUGHTS?
(i dont want to MF'ing hear that the CMM isn't the best way to check TIR. i know this. i want to know what i can do on this CMM to achieve the most accurate results. )
