Complex solid modelling

[andymel]

I've used AutoCad for some time now, but have only recently started modelling with solids. Generally I design rotating machines such as motors, alternators etc and these are relatively easy to model (being cylindrial in basic design) using revolve, intersect, union and so on. Getting solids from the 2D design layout is a matter of generating the right polylines and extruding.

I'm now trying to tackle a complex gearbox - the geometry of the castings is a bit more difficult. Is this kind of modelling a worthwile cause in Autocad 2000? Can anybody point me to a decent tutorial for complex solids (imagine the gearbox on your car!).

I've been told to give it up & try something like Pro Engineer but damn - I just can't afford something like that. Any advice?

[Mr T]

I think it's pretty easy, depending on your skills, to model a gear wheel. As long as you are competent with the EXTRUDE along a path feature. Check out what others have done before.

http://www.cadtutor.net/forum/viewtopic.php?t=74&highlight=spiral

Lisps will help automate common gears etc.

Nick

[Ash Mair]

Thanks, I just read my post again (goddamn, what pathetic reading - you must think I'm a real idiot - it was late at night though!).

What I was trying to say was that yes - you are right - the simple components that can be extruded/revolved (simple mechanical parts) are fine. I'm struggling with the larger castings. After spending most of today using the shell and solidedit command in general I made some progress, but it seems like one step forward and two back. Admittedly I am a newbie when it comes to this sort of thing but trying to union/interface/slice 20 or more 'pieces' to form one solid in autocad 2000 seems like an exercise in futility. Experience may help matters - thats where a decent tutorial may help. I'm sure there are add on packages that may help, I'm talking to somebody about Inventor. Does anybody know of tutorial that may help? All I can find are chairs and tables.

Tanx again

[Mr T]

When I learnt Acad 200, I struggled with solids like you say. I discovered the 'Learning Assistance' CD that comes with acad. It has sample enginnering castings etc to work in in 3D, with tutorials inc video clips. It's pretty good.

If you post up or email me a 2D orthographic I'll endeavour to post a tutorial up on my site to help you on specifics.

Nick

[hendie]

have a look at Alibre Design (www.alibre.com) ~ I've played with it recently and was very impressed with it. and take a look at the price ~it's unbelievable compared to its' market competitors.
and you should be able to create just about any complex solid you would need to for something like gearboxes. The learning curve is pretty reasonable and I found it to be quite intuitive. definately worth a look