I was wondering if 60 size planes can perform acceptable 3d manuevers? If not what is the smallest size a person should go with. I currently fly a sig somthin' extra but wanted to move up to something better but am intimidated by the really large aircraft.

The bigger they are the better they fly!! As for 3-D I can't help you, as I am just getting into it myself. But the bigger planes fly much better than the smaller ones. They cost more, but they are super easy to fly too.

Check out the threads on the U Can Do 3D from Great Planes.

The plane needs at least a 90 size 2 cycle, but appears to be performing well. IMHO it is bigger than a 60, but not that much. Read the posts and decide for yourself.

BTW, yes, a 60 size airplane will 3D. I've seen 40 size airplanes perform some impressive 3D manuvers. But, it does have to be set up correctly and supposidly it is harder to do with the smaller planes.

Yes, I have seen people torque roll with a 40 size plane. You have to have sufficient power to weight, be light weight, and have extreme throws on your control surfaces.

I have a 58" Great Planes Cap 21 kit built in the mid 80s that'll 3D with no modifications. It was originally a 40 size, but we put a Saito 91 in it. Will do super tight waterfalls, harriers and harrier lands all day long and will do the most violent blender I've ever seen not destroy an airframe. It is very difficult to hover though, although admitadly I'm not the best at this yet.
I recently broke a Irvine .53 in on this plane, same setup, and it would still waterfall and blender, but not quite enough propblast do set the tail real deep for a slow harrier like with the Saito. That was on a 12.25*3.75, so that prop was about 2 inches shy of the one on the Saito. It was easier to hover though, probably cause it was more tail heavy. I actually got 1 clean rotation out of it, and like I said, I haven't mastered that maneuver yet.

Planes as small as park flyers can do 3d. One of the pattern guys showed up with the Radical RC Edge 540:

http://members.aol.com/davthacker/edge540.htm

10.5 oz flying weight.. It was absolutely amazing to see this thing fly! It's on my christmas list as a cheap way to learn 3d in the backyard.