Interference Detection

How do you guys handle fasteners when doing interference checking. I have
found that the nuts and bolts interfere do to max, min thread diam
representation in the nuts. I bore out all nuts so that I don't have to
worry about multiple interferences when checking assemblies.

Any other approaches?? Do you just suppress all fasteners?

Tom

 

Tom,

I just go surface to surface, a #10 screw and a #19 tapped hole are both
..190 dia. Likewise with nuts/bolts, etc.

Dennis

 

This is a big problem. One solution is to go to the configuration manager
and use the selection tool hidden there to select all the hardware and
suppress it. It isn't too hard to set up a rule to do this and then save it
for future use.

There should be an option in interference detection to disregard fasteners.

 

My current procedure in large assemblies is to insert a fastener group(assy
w/ bolt, washers, and nut) in an appropriate subassy so that when all
subassy's are mated, all fasteners are already installed. This prevents me
from having to install fasteners forever. My last assy had over 1800
fasteners. Yet, I only inserted maybe 30 fastener groups into subassy's.

I try to have as few config's as possible. It seems to help reduce overhead
and increase speed. That's why I've been boring out nuts and saving them.

I'll have to learn the advanced selection tool. That sounds like it may be
a better option.

Tom

 

I wrote a macro that generates an Excel file that keeps a list of
interferences that you want to ignore (two components plus the
interference volume). So you end up with two lists -- valid
interferences, and interferences you want to ignore. It's slower than
the standard interference function, but overall it can be faster since
you don't have to eliminate all spurious interferences. I haven't
tried it yet with 2004. Drop me a line if you want me to email it.

Eric

 

I have used that method in the past. Works very well, but I am not sure
this could be incorporated with Toolbox.

 

Kman,

That is basically what I do now, except I drill out the nuts instead of
changing the bolts. This way the nuts always measure the specified thread
diam. (i.e. 1/4-20 unc).

I've been doing this for a while. I was just curious if there were better,
or easier approaches.

SW always seems to have 90+% solutions. It's just that I wish we didn't
have to always make up the rest of the percentage manually.

You would think that the guy doing the library and the guy doing
interference detection would realize that they would eventually detect each
other (1000's of times in a large assembly) and try to resolve their
differences.

Tom

 

Kman,

Good point, I add drill & tap notes to cover them. Not the best, but it
works. SW still needs to address this issue so that we all don't have to
develop our own work-arounds.

The only reason that I do it this way is that all measured sizes are the
named thread size and as Mike said this makes things kind of obvious to
others. Having the actual min and max thread diam's on the parts is
accurate, but seems to cause more work than it prevents. I ,almost, always
check for interferences just to prevent accidents.

Tom