Ole
I was kind of thinking the same thing about the extrusion process. I just didn't know if they did any milling after the process. It appears from the link Van provided that VSC Tools does. They have some nice stuff.
The VSC Tools looks like they have a lot of nice stuff and they're the link that ted Calver linked out to. I've watched a few of their videos now. They have one specifically on "flatness" that was interesting.
Van and Glenn
The entire fence system would be made of aluminum extrusions. I used 80/20 as a reference, since they seem to be a largest online supplier of aluminum extrusions. Until you provided that link to VSC tools, they were the only place I knew of. One of the products in 80/20's catalog is identified as 40-80/20, but it has a solid face that could be used as the fence, thus avoiding the issues everyone identified as having a profile line up on one of the slots.
The plan is to mount the rails on the side of the machine just as Martin did in his video. Martin appears to be using the extrusions only for a back fence to ride on, but I am hoping to do both with it. Main fence, and back fence, if necessary. Primarily though the main fence. I want to get rid of bolting the fence structure to the top of the table when it's in use.
I've seen some really nicely designed router fence offerings through the years. Incra, WoodPeckers, Bench Dog, etc, and always wondered why no one makes the equivalent structures for a shaper table. I know the shaper is somewhat of a oddity in the home workshop, probably because folks are afraid of them, but I have to believe the there are more folks than just me that would like a nicer fence than the OEM supplied, but could just never justify the cost of professional fence, like an Aigner, or something like that. And to be honest, I don't use a power feeder, so the ability to bolt rollers, feather boards,guards and such, to the existing T-slots would be useful. I learned to use a shaper as a 12-13 year old without a power feeder, and there wasn't one in the shop class. I'd like to have one though. They're nice.
Once I get done "playing around" with the idea, I'll post what I came up with.
"The first thing you need to know, will likely be the last thing you learn." (Unknown)