Cs autorouter pants ?

[Simon]

I have just tried to auto-route a board. But frankly I am not impressed, tracks are hitting things where with minimal work I can shift them out of the way by moving the offending track alone and nothing else and I have tracks going off the edge of the board and once this happens different net tracks hit each other - I mean what the hell is going on ? the design is not complicated and simple enough for an auto-router, with a 4 layer board, 2 layers of ground plane so plenty of options for the auto-router yet it chooses the illegal paths. Is there something missing in the basic setup of the auto-router or is it really this shit ?

[tautech]

Auto routing a full board is rarely successful unless it's gawd simple.
Rules are everything to a decent job and the default rules will need tweaking with.
I learnt long ago that AR is a useful tool but a lot depends on how you use it.
Sometimes it's great to let you see traps in your layout and go back to change blocks or part orientation before further attempts.
I've seen Dave in vids only route one net at a time, lock them in place and proceed with others interactively to get a layout he's happy with.
Practice, practice, practice. 

[Simon]

Yes I didn't really want to make this a manual versus auto discussion. Of course there is stuff that needs manual routing and I will do that first, then all of the silly obvious ones can be done by machine faster than I could. The design is not critical so even a poor job would not impact significantly but what I am getting is pretty bad, I mean with 2 ground planes under the board how can it decide to take a ground route outside of the boards boundary to route it? I mean that is just one massive bug

[tautech]

It maybe just that Simon, a simple bug in the defaults that prohibits routing through a plane. Check the rules, there should be one in there to fix it.

[Simon]

Well I've looked around and I can't really see the option, the plane is on the GND net, it is fair game. Putting vias in that link various parts to the planes does not throw up any errors

[voltsandjolts]

Unfortunately, all autorouters are pants.

[Simon]

yes but there are auto routers that you need to clean up after and there are auto-routers that violate their own rules.