Free software for calculating True Position. For Windows and Mac.
True position is the deviation from the theoretical location of the hole or feature
as shown on the drawing. A True Position of 0.000 would mean the
hole is exactly where it is supposed to be. A True Position of 0.010
means the hole is 0.010 off from where it is supposed to be. If that
0.010 is more than the tolerance given on the drawing then the true
position of the hole is out of tolerance.
You need to know the basic dimensions of the drawing. This will
calculate them for you.
1. Put in the Tolerance according to the drawing.
2. Check the Diameter checkbox if Diameter True Position.
3. Fill in all the maximum and minimum dimensions from the drawing.
This will calculate the mean basic dimensions for you.
4. Fill in the Actual X and Actual Y dimensions you measure on the
5. If using Drawing Tolerance allows Maximum Material Condition,
check the checkbox and fill in the Actual Hole Diameter on the part.
No need to press Enter. Calculation is automatically updated
whenever anything is changed.
When True Position calculated result is in RED, the value is out
Maximum Material Condition
If the tolerance callout has the M symbol then you are
allowed extra tolerance. This extra tolerance comes from how much
the actual size of the hole is larger than the minimum allowed size.
For the short cut way, if you already know how much the
hole is off in the X and Y direction, you can just put the deviation
from basic in the Actual X and Actual Y boxes along with the
Tolerance, and leave all the other boxes blank.
MMC requires the min allowed diameter and the actual diameter of
Inch or Millimeter input doesn't matter as long as you use the same
Radial or Diameter True Position.
Most tolerances on the drawings you see will have the diameter
symbol in the feature control frame. So .005 means the tolerance
zone is a circle around the basic point with that diameter. Without
this symbol the .005 is a circle with that radius around the basic
point - which is twice the size.
|Plus and Minus Dimensions
|You can also enter dimensions in the plus and minus form
to make it easier if your drawing has this kind of
Using only the Max edit boxes, after the main number add
plus and minus symbol or just plus or just minus and then
the second number, into the Max dimension box.
You can also have 0.2525+.01-.005
The min, max and mean are automatically calculated from
this. You can see the calculated mean dimensions in
The Print button will print a picture of the form as
shown on the screen.
Windows Version Here:
No installation needed. Just put the file somewhere
and run it. For Windows XP,Windows 7,8
Download Mac OSX Version
Mac OSX 10.7+
iPhone and Android Version Here.
These files are digitally signed by i-Logic Software.
Questions to: email@example.com