Hello,
I am often having problems trying to REVOLVE ojects in Autocad.  I get error messages like  " cant revolve  intersecting curves" etc. the reason I found out that my 2D polylines  have bits of  double lines hidden in  short sections  of  the 2d drawing. Eventhough on LIST command I   see it as a closed polyline, I dont seem to be able to Revolve the object.
 
I would like to know how I could detect where these short pieces of double lines  exist in the 2 d drawing  So that these lines can be erased.  It is very frustating  when you try to revolve a long piece of multi grooved  shaft  and it won't revolve  because there is a tiny piece of double line hiding  in the drawing 
 
I understand that there is a way of doing it which means going over the drawing  sections  which will indicate - "one object found or two objects found "etc.  but I don't know how to do this.  Thanks in advance. Joferna

It sounds like you are talking about the OVERKILL command found in Express Tools.It also sounds like someone has some bad CAD drafting practices if there are lines one atop each other and/or overlapping lines.

The polyline cannot cross over itself at any point (like a figure 8)

Thanks John,  yes this Overkill is what I am looking for . You are correct about the bad  drawing practices. I am constantly trying to improve my drawing habits.However, these errors happen when instead of using PEDIT, PL is used and drawn over any vestiges of 2 d lines.
 
Regds Joferna

Hi Cisco
 Thanks for replying- good advice