converting units
converting units
(OP)
Need help with converting units from metric to inches. I tried using the 'ug_convert_part' program from http://www.vickers.de/ugconv.htm. This works fine, but my sketch dimensions and other values stay in metric. I'd like all the values to be changed to inches. Is there another way to convert them? Using NX4.0





RE: converting units
http://ne
Most important to note is the following
ug_convert_part -mm to convert to mm
ug_convert_part -in to convert to in
I believe the site you listed shows a Direction option with an inch,mm selection. The picture on the site says Convert Inch<->mm at the top of the window but the Inch option is selected. Maybe Direction is direction from and not to. Check what happens if you select the other direction option or use the PLMworld tip I've shown above.
I've used this at the last UG company I worked at and there is no need to run a separate program for it.
Michael
RE: converting units
As an example of what I mean by 'design intent', take the following example as a case in point:
I have a part file created in NX 4 using metric database units. Say I have designed a sheetmetal part where the material thickness as 2mm and at one point the design required that a 2 inch hole needed to be punched in one of the flanges of the sheetmetal part and the user, using the option to change design units while defining a parameter, either explicitly in the expression system or by changing the input units under Analysis/Units. OK, now assume that the part was converted from mm database units to inches. The original design intent of the sheetmetal thickness being 2 mm and the hole being 2 inches is unchanged since those units are part of the models design specifications.
For another example, let's say that there was extensive use of measuements and complex equations involving the use of several of the pre-programmed engineering handbook functions available in the expression system calculating say some beam deflections or some of the forces found in the 'Mechanics' set of formulas.
In the above examples, how would you expect the conversion software to resolve all of the possible units implications? This was never the intent of the 'ug_convert_part' and there are no plans to change that since this would be a totally unrealistic task. Sorry, the 'ug_convert_part' was intended only to convert the untis of the database and not the engineering oncstraints and parameters that make up the designer's intent. The utility was intended to overcome those iussues that involve attempts to mix part files of different units in such operations as assemblies, WAVE linking, etc.
I hope this helps explain what is and what is NOT happening with using the 'ug_convert_part' utility.
John R. Baker, P.E.
Product "Evangelist"
NX Product Line
UGS Corp
Cypress, CA
http://www.ugs.com
RE: converting units
RE: converting units
"[Path to UGII directory here]\ug_convert_part.exe" -mm "%1"
Omit the brackets but INCLUDE the quotes where shown. What is shown above will convert from inch to metric. To convert from metric to inch, omit -mm and add -in while leaving everything else the same.
Tim Flater
Senior Designer
Enkei America, Inc.
www.enkei.com
RE: converting units
Tim Flater
Senior Designer
Enkei America, Inc.
www.enkei.com
RE: converting units
let's say I inadvertently create a part file in INCH units. I then create all of my sketches, features etc ... On noticing this mistake, I now want to convert the part file to METRIC.
I use the ug_convert_part program (as I always have done for many years now), but it leaves all of my expressions as INCH, and doesn't allow me to change them to MILLIMETER. What I now have to do is edit all of these expressions adding mm() to the values.
Why not at least allow the user to change the "units" of an expression ?
Paul Phillips
Specialty Engineered Automation
http://www.sea4ug.com
RE: converting units
OK, so when we look at a file to convert and we see an expression equal to say '10 kg', what do we convert it to? '22.05 lbm'? '0.057 slug'? Or perhaps we play that "let's assume that we're in an Earth bound frame of reference" and convert it to '22.05 lbf'? But what if this part file came from NASA or Aero Jet or any number of companies where they actually DO have 'Rocket Scientists' working for them and the problems that THEY may be solving really doesn't deal with "Earth bound frames of reference" and then the '10 kg' really was meant to be a Mass and not a Weight, but I still have to figure out whether the user is expecting 'lbm' or 'slug' as a result. And because of these 'quirks' (Engineering vs. Physics) in the use of units, any formula that involves Mass or Weight is going to be very difficult in terms of a direct conversion from one set of units to another.
Therefore, with the advent of the NX expression system becoming a full fledged 'engineering' formula solving system, we had to decide what it actually meant to 'convert' a prt file from one set of units to another. The alternative would have been to create a totally new scheme that would have had TWO numerical based systems, one remaining unitless representing only linear and angular values and the other for more complex computations, but even that would have required a very complex and tedious 'interface' so that numerical values could be shared yet still be properly recognized after a part conversion.
Sorry, we therefore opted for something workable and logical, but we had to accept that the world was no longer as simple as it once appeared to be, and one of the victims of that were blanket unit conversions.
John R. Baker, P.E.
Product "Evangelist"
NX Product Line
UGS Corp
Cypress, CA
http://www.ugs.com
RE: converting units
thank you for that information.
back to my last question, without converting a partfile, why can't I change the units of a feature ? Let's say I create a 2 INCH diameter hole, as that was the original design intent. Now, the design intent is that hold must be 50 MILLIMETRE diameter. Without creating an intermediate expression, or deleting the hole, how do I now change it to be MILLIMETRE ?
Paul Phillips
Specialty Engineered Automation
http://www.sea4ug.com
RE: converting units
For example, lets go back to my 10 kg problem from the previous reply. What if I edited it to be 22.05 lbf instead of 0.057 slugs and it was being referenced as a Mass in some engineering formula?
With the extra functionality comes constraints and limitations. We therefore feel that the burden is on the users to make it unambiguous as to what it was that they were trying to accomplish when changing the 'design intent' of your models.
John R. Baker, P.E.
Product "Evangelist"
NX Product Line
UGS Corp
Cypress, CA
http://www.ugs.com
RE: converting units
My two and half cents
-Dave
PLM Exchange
http://plmexchange.net
http://groups.google.com/group/NX_CAX/
RE: converting units
If it's MY intent that MY 2 inch hole now needs to be 50mm, then I should be able to make that change and deal with the consequences. Surely if the expression has a UNIT, then "interpart expressions" (I use a lot of these, both ALL directions) carry that UNIT through.
I'm just SO frustrated with these UNITS. I guess if I needed to deal with Engineering formulas day in, day out, it might be a different matter. But I don't, and having to deal with INCH / METRIC partfiles is a pain. Additionally, pre-NX3 deformable components no longer work in cross-unit partfiles because of expressions having no units.
Paul Phillips
Specialty Engineered Automation
http://www.sea4ug.com
RE: converting units
John R. Baker, P.E.
Product "Evangelist"
NX Product Line
UGS Corp
Cypress, CA
http://www.ugs.com