Balancing with metric units

[Ralph2]

An issue came up the other day for which confused me. I operate a Schenck hard bearing balance machine with CAB 690 software. My units are typically in inches and my tolerance is in gram.inches.

With the CAB 690 one can transpose correction planes. If I transpose the correction planes to the same plane as the bearing then I can read the force at that bearing, if the radius is set to 1 inch then the resulting unbalance can be directly compared to the tolerance applied to that bearing.

Last week a customer gave the tolerance in gram.millimeters and requested a printout of the force (correction) at his bearing positions. However I was confused as to what to set the radius to. When I set it to 25.4 (1 inch)the resulting correction stayed the same as when I set it to 1 inch.. however I do not think the relationship to the tolerance was correct in the same way as when using inches and gram.inches.

So... all this to ask.. when dealing with metric units, tolerance in gram.millimeters... what is the base radius dimension?

In America 5 oz.inches means 5 ounces at 1 inch 147 gram.inches).. In metric 1554 gram.millimeters means ??? 1555 grams at (1) millimeter ???

If you can make sense of this... thanks
Ralph

 

[electricpete]

In America 5 oz.inches means 5 ounces at 1 inch 147 gram.inches).. In metric 1554 gram.millimeters means ??? 1555 grams at (1) millimeter ???

I am not familiar with your balancing machine and not sure I followed your whole question. But the answer to this last part would seem to be "yes". Unbalance can be expressed as product of mass and radius. So 1554gram millimeters could be 1554 gram at 1 mm or 1 gram at 1554 mm.

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