I am wondering what methods and techniques people are using for dealing with splices in Pro/CABLING. We currently use a splice part that has 2 entry ports and is coin shaped with the same outside diameter as the bundle the splice is in. We put the splice on a network location and redefine the internal portions so the segment of network leaving the splice exits the 2nd entry port. Any wires or cables going through the original location now must go through the splice. These splices seem to be unstable and cause no end of problems when flattening the harness. If you revise the harness to add or remove a splice the flat harness will fail at the splice location and will need to be re-flattened. This also causes significant portions of the drawing fail. It's a huge loss of time for something that should be pretty simple.
We are looking at an alternate technique where the splice part is much smaller and is put in a "by-pass" section of network right next to the main network. Only the spliced wires get routed to the splice and it ends up being "hidden" by the bundle. On the flat harness the main network is flattened and then 1 piece of network leading to the splice is flattened so the splice can be assembled to it. This seems to allow splices to be added/removed from the harness without causing major failures with the flat harness and the drawing. It does seem to have some problems with auto routing though. Even if the locations on the splice are set to be secondary, wires unrelated to the splice sometimes get routed through it.
I would like to know if others have tried this by-pass method and if it has worked for them. I'm also interested in any other techniques that people have tried.
Splices are notorious for piles of circular references and harness flattening problems. At the top level assembly, the circular references in our cables were causing loops and failures that caused the top assembly to take up to 6 hours to open.
There were many cables whose circular references were killed easily... They had no splices. There was one monster cable with multiple splices. It had 29 circular references as well. Because the cable was so difficult to flatten it became a sacred cow. No one was ever permitted to tweek it ever again! I started killing circular references in the top assy, there were over 120 of them... although there were only 67 being reported. When I was done, there were(any guesses?) 29 of them... all in that one cable. I created a simplified rep for top level assembly drawings that did not have that cable in it. Now the top level assembly opens in 20 minutes...
When I am routing a cable with splices, I attempt to keep the splices in the backshells. (good practice, they are easily checked and serviced that way)Also, I only route to the backshell itself. It's like magic - No splices to route ever! Some cases do not allow The splice to occur inside the backshell. These I fudge! Either route different gauge wires To the same location for purposes of calling out a splice, or just continue routing to the backshell if cable diameter is not an issue. If you really really really want a visible Splice on your drawing, you can always add a "label" feature and call it a splice...
As long as your drawing and resulting cables are accurate, I am willing to let my best modelling practices slip a tad. This is especially true if you have any concern over maintaining your top level assembly... If you get enough splices, and enough circular References, your top assembly won't even open anymore, it will just loop for an hour then crash.
Weighing risk to benefit... DEATH TO ALL SPLICES!!!
Everybody's gotta vent every once in a while...
Frederick Burke Avionics Installations Engineer Fire Scout VTUAV - Unmanned Systems Northrop Grumman Corporation 858-618-7163 858-618-7186 (FAX) -
Thanks to all who replied to my Pro/CABLING splice query. The general consensus was that splices just plain suck. I got few different ideas:
1. Make them with only 1 entry port. This allows them to be removed from the flat harness with out it blowing up. Reflattening is still required if you want to add one though. 2. "DEATH TO ALL SPLICES" 3. Treat them as a regular connector component and don't use splice functionality at all. 4. Place them on a "by-pass" section of network.
I really like #2 but I'm going to try some combination of #4 and #1 and/or #3. I don't have very high hopes though.
Anyone know why PTC hasn't bothered to address the splice issues? Seems like it's a very basic requirement of what anyone would call a harness modeling tool.