MB16 changing units from imperial to metric

# Thread: MB16 changing units from imperial to metric

1. ## MB16 changing units from imperial to metric

Living in America, I use the imperial measurements, but I have a small project that uses oversees components, all in metric system.
While I can use the conversion calculator, I was wondering if it’s easy enough to flip from In to mm on these machines?

2. ## Re: MB16 changing units from imperial to metric

IMHO machines are best kept in their native units from the OEM. This includes the machine parameters and all the original setup data. Obviously maintenance data does need periodical adjustments.

That being said... and that the USofA still hasn't taken up the decimal system. You are still are just using numbers to program toolpaths. Whether you use 0.25" or 6.35mm, they are just numbers, your measuring tools are likely imperial, the tools in the machine are all set, your CADCAM and post processor have proven themselves using imperial, you are more comfortable using inches.....

Why ???

I have seen some machines that are in one unit, tool comps & parameters in same unit... but one parameter change allows a different unit program to be run. It is problematic to work in this mindset.

I work opposite to you, metric system locally, and got to make stuff to US drawings.... yeah, we did have our drafting dept try to convert a UNC thread designation to metric (then rounded the numbers) .. I laughed so long, it was just so classic stupid

3. ## Re: MB16 changing units from imperial to metric

You would need to change your post processor to output the program in metric and then you just change from G20 to G21 at the beginning of the program. Here is some text from my manual, this is older Centurion 5, so yours may vary.

3.9 Metric dimensioning mode (modal) (G21)
This function will cause the system to go into the
metric mode. In this mode the system will accept
dimensions in millimeters (mm) . This function can be
initiated in MDI or program mode. In metric the actual
machine position may not exactly agree with the program
position because of the conversion. Feedrate in the
metric mode is in millimeters per minute (mmpm) .
Notes on Inch/Metric
The CNC does a conversion from metric to inch, and inch
to metric, on all tool offsets. This means that a 1.0
inch offset entered in the inch mode will change to 25.4
mm when the system is switched to metric. The opposite
happens for metric entries.

4. ## Re: MB16 changing units from imperial to metric

Thank you Brian.
I was able to sort thru the 18,523 pages of the manual and came across this page:
MDI G21, save, and I was done. Great! Easy.

Originally Posted by Brian L
You would need to change your post processor to output the program in metric and then you just change from G20 to G21 at the beginning of the program. Here is some text from my manual, this is older Centurion 5, so yours may vary.

3.9 Metric dimensioning mode (modal) (G21)
This function will cause the system to go into the
metric mode. In this mode the system will accept
dimensions in millimeters (mm) . This function can be
initiated in MDI or program mode. In metric the actual
machine position may not exactly agree with the program
position because of the conversion. Feedrate in the
metric mode is in millimeters per minute (mmpm) .
Notes on Inch/Metric
The CNC does a conversion from metric to inch, and inch
to metric, on all tool offsets. This means that a 1.0
inch offset entered in the inch mode will change to 25.4
mm when the system is switched to metric. The opposite
happens for metric entries.

5. ## Re: MB16 changing units from imperial to metric

I'm making a mounting plate for a buddy which utilizes several of these LM bearings. I'm just doing it manually at the mill, but it's nice to jump 26mm vs. 1.02 inches each time. I do distance call and move from one to another. I don't have to think about converting, and that makes it simple.
https://makerstore.cc/product/bear-hgh15ca/

Originally Posted by Superman
IMHO machines are best kept in their native units from the OEM. This includes the machine parameters and all the original setup data. Obviously maintenance data does need periodical adjustments.

That being said... and that the USofA still hasn't taken up the decimal system. You are still are just using numbers to program toolpaths. Whether you use 0.25" or 6.35mm, they are just numbers, your measuring tools are likely imperial, the tools in the machine are all set, your CADCAM and post processor have proven themselves using imperial, you are more comfortable using inches.....

Why ???

I have seen some machines that are in one unit, tool comps & parameters in same unit... but one parameter change allows a different unit program to be run. It is problematic to work in this mindset.

I work opposite to you, metric system locally, and got to make stuff to US drawings.... yeah, we did have our drafting dept try to convert a UNC thread designation to metric (then rounded the numbers) .. I laughed so long, it was just so classic stupid

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