4 Replies Latest reply on Jun 5, 2012 12:20 PM by Jonathan Smith

    discrepancies in file size of similar parts

    Soha Park



      For a multitude of reasons, I decided to make my own mini toolbox of Hex Bolts with dimensions taken from Mcmaster. 


      The parts consists of an extrude (hex head), a cut-revolve (top chamfer), extrude (thread length), and chamfer (thread end).  I started with 1/4"-20 bolts, and created configurations from 1/2"L to 3 1/4"L at 1/4" increments.  Then I "saved as" and did the same thing for 5/16" and so on.  The only things I modfied was the hex head dimensions and the thread diameter. 



      For some reason, my file sizes are ranging from 250kb to 1mb. 


      For example my 9/16" hex bolt is 1 mb+

                               3/4" hex bolt is 255 kb

                               5/8" hex bolt is 521 kb

      They're all created from "saving as" from 1 size previous.  All the files have the same 4 features (2 extudes, 1 rev cut, 1 chamfer)



      One of the reasons for this is to reduce file size and to simplify my assembly.  Any suggestions?   Thanks


      EDIT - when I reopened and saved the 3/4" just to check the file before uploading the part, it went up from 255 kb to 623 kb.  I have a similar 7/8" bolt that has a low file size. 

        • Re: discrepancies in file size of similar parts
          Jerry Steiger



          You haven't gotten any answers from folks who actually know the ins and outs of file size, so I will bless you with what little I think I know. File size will go up as you add more configurations. If they all have the same number of lengths, then I would expect them to all have the same "basic" file size. A good part of the file size is taken up with image data. I suppose that could vary with the physical dimensions of the parts. It might also depend on what the parts looked like in when you saved them. The files are a type of composite data type and often end up containing redundant data. Doing a "Save As" often strips away part or all of the redundant data, reducing the file size. You can run a handy little program called Eco-Squeeze to reduce the size of your files in a controlled manner, as it has a number of options. You might be able to use it to better understand where the file size is coming from.


          I have no idea why the file size for one of your parts would balloon up just from opening it up and resaving it.


          Jerry Steiger

          • Re: discrepancies in file size of similar parts
            Scott McFadden


            This is the age old question.  If you do searches on this forum you will see this question asked multiple times.

            Jerry is correct in what he said.  I also have to ask if there are any physical properties involved with these models

            like material.  If so that adds to files size as well.

            • Re: discrepancies in file size of similar parts
              Alin Vargatu

              There are a few things you can do to reduce the file size further, but in my humble opinion it is a waste of time. Just by switching to a different configuration, you will add that geometry in the file (by (re)building it). Keep in mind, that most of the times you want that geometry information to be in the file, in order to save opening or rebuild times (especially when using that component multiple times, in multiple configurations in an assembly).


              The attached file's size has been reduced from 623KB to 267KB with these settings, (but the main thing is having only one configuration resolved):





              BTW, this is just an empirical experiment, since I know very little about what information goes in a file. I am going to restate the fact that In my opinion the speed (fast rebuild times) should trump the file size.


              The fact that a part file is 10 times smaller, but it takes 10 times longer to rebuild when used inside an assembly is a disadvantage, not an advantage.