I'm having a problem with some of the files at work growing in size from simply copying objects in from another drawing.  These aren't blocks are massive amounts of line work.  I have a file that is 487kb and when i copied in some lights from another drawing, the file size grew to over 8mb. The lights were nothing more than 5 circles. I've used -purge, regapp, wblock commands all in an attempt to try and clean the file up with no avail. Also tried a lisp to clean out the layer filter. I'm stuck.  Does anyone have a suggestion or ever run across this type of issue?  Any assistance would be greatly appreciated. 

Yes, I've run across the problem.  In some cases the file size ballooned because someone brought in content that was originally created in Microstation.  Could that be the case here?

The file was created using AutoCAD. I doubt there is anything from microstation floating around in the background but i don't know how to check. I know the problem is coming from copying stuff in from another file which shouldn't cause such an issue.  I'm just completely stuck at this point.

So what have you done to try and reduce the file size?Have you run the OVERKILL command on the drawing?Have you used the command line version of PURGE (-purge) first purging Regapps then running it a second time and doing a Purge > All?Have you done an AUDIT on the drawing?Have you checked the number of linetypes loaded?

I tried all of those things but to no avail.  I finally sorted it out though and was about to post my solution.  I ended up doing the following and it worked really well.1.)  DXFOUT2.) Open new DXF file and PURGE>ALL; -PURGE>REGAPPS and AUDIT.3.) SaveAs the new DXF file as a DWG.after I did that, My file went from &MB to around 200kb.

Glad to hear you got it solved.  Thanks for the update.

I had the same issue. Usually they are drawings created in Microstation. The solution is simple: delete wipeouts. deleting blocks like sinks and toilets reduced the size of my drawings significantly too ('m not sure what was so special an=bout these objects tho) 

It's not just a matter of deleting wipeouts in drawings created in Microstation.  It's all the linetypes that get associated with the drawing.  That's why AutoDesk just came up with a specialized tool for deleting these linetypes.

I've seen drawings having thousands of unused linetypes that won't purge with ordinary methods. A good workaround is outlined in at the posting dated "01-14-2013 09:47 AM" at http://forums.autodesk.com/t5/AutoCAD-LT-General/Linetypes-Will-not-Purge/td-p/3236334/page/2. Autodesk's new tool to do the same task will be welcome - if it works and is documented well.I've also seen larger than expected drawings due to embedded object data. Civil drawings often have lots of objects with associated object data. In Civil3D you can get rid of uneeded object data with the ADEDEFDATA command. Converting a drawing that holds object data to a dxf should also get rid of the data because the dxf file format has no provision to carry it. I doubt that unused linetypes or regisetered applications would be carried into a dxf conversion either...

If the unused linetype had as its source a Microstation drawing then it will carry over into a DXF file.  DXFOUT/DXFIN was a documented way of purging unused entities and has been around a long time.  Unfortunately the method did not always work thus the reason why AutoDesk released the tool you mentioned.  BTW.....the tool does work as advertised.

Yes John, there is much more than just wipeouts. However I got drawings created in Microstation from the architect that were about 25MB each. I was able to reduce it to about 10MB by deleting blocks and purging everything possible. By deleting wipeouts I got from 10MB to just about 1MB. it is strange how the Microstation drawings are that big and the way it creates dwg - blocks within blocks. I hate Microstation ;).I'll try the dxf option next time as I wasn't thinking about it. Let's see if smth important will not get lost.

I got some drawings created in Microstation last week so I tried the dxfout ... well, the file size changed from 8MB to 35MB! Strange one really. I had to clean it manually again.