I am having some trouble with measuring accurate Diameter size, I have read some threads on this type of thing but the solutions provided pertain to mostly Bridge Type CMMs and I am using a Romer Arm. So I'm interested in any tips you guys may know of to get more accurate results. ... oh and it seems I have more trouble when working on sheet metal parts and I can imagine its due to the thickness of the material. Thanks in Advance
I've done a few hundred thousand holes like you describe. Here's what you want to do:
1) Use an Auto Circle, not a Measured Circle. Because this allows you to...
2) Use 3 sample hits to create a local plane that the circle will be flat to. Because this allows you to...
3) Use Plane AutoTrigger. Because this allows you to probe hits NOT where you trigger the arm, but when it crosses the cut-plane.
4) Use the appropriate number of hits and a depth = 1/2 the thickness of the metal
In this way, you can probe 3 hits around the circle, the arm will emit a tone, and you can 'rub' the probe on the thin cylindrical surface that defines the bore. Every time you do, the arm will capture a hit exactly where you want it to be, at the Depth you've set.
Review your training if you don't remember how to set up the Plane AutoTrigger. Do not use the Point Autotrigger in this instance, it won't work...and I can't get into why, today.
Now your hits are placed correctly. If you have enough hits, then your circle will be repeatable. Good luck.
PS.
Most of the time with the arm, we really don't need to precisely probe points. Whenever you do, and your body's precision is the real problem, look towards one of the two Autotriggers for help.
I've done a few hundred thousand holes like you describe. Here's what you want to do:
1) Use an Auto Circle, not a Measured Circle. Because this allows you to...
2) Use 3 sample hits to create a local plane that the circle will be flat to. Because this allows you to...
3) Use Plane AutoTrigger. Because this allows you to probe hits NOT where you trigger the arm, but when it crosses the cut-plane.
4) Use the appropriate number of hits and a depth = 1/2 the thickness of the metal
In this way, you can probe 3 hits around the circle, the arm will emit a tone, and you can 'rub' the probe on the thin cylindrical surface that defines the bore. Every time you do, the arm will capture a hit exactly where you want it to be, at the Depth you've set.
Review your training if you don't remember how to set up the Plane AutoTrigger. Do not use the Point Autotrigger in this instance, it won't work...and I can't get into why, today.
Now your hits are placed correctly. If you have enough hits, then your circle will be repeatable. Good luck.
PS.
Most of the time with the arm, we really don't need to precisely probe points. Whenever you do, and your body's precision is the real problem, look towards one of the two Autotriggers for help.
