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Change in accuracy from reducing pre-hit distance?

I’ve been trying to reduce CMM runtime in our QC department and I’ve found that using fly mode and reducing the pre-hit/retract distance by half, it cuts an average of 13% off the runtime for our product. I’m trying to make this a standard, so I want to show my time studies to management. Before I do, I wanted to make sure there were not any changes in accuracy.

From what I know, the only downfall to shortening the pre-hit distance from .1 to .05 is if measuring a non-consistent part like a cast part, the probe might move to close before taking a hit and throw an error when it touches the part. I also know it shortens the distance it will search past the theoretical point, but that can be adjusted by setting the check distance, right? So, is there any other reason you wouldn’t want to shorten the pre-hit distance?
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  • What machine are you using? Just wondering because I had issues with this before from a sheffield. The drives needed a certain amount of distance to stabilize before taking a point, especially if the points taken weren't straight in X Y or Z. I never liked those machines. So going along the lines of what JEFMAN said in his second sentence.

    Try calibrating your sphere with the same prehit and retract you are using for the program and see if you get any calibration errors.
  • I’m primarily running on a Hexagon Global S. I’ve been calibrating to the same pre-hit distance I’m using in the program. I haven’t noticed any accuracy issues myself, but wanted some more experienced opinions.
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