I suggest mounting a large piece of 3/4 inch plywood-at least a 1/3 to 1/2 of a sheet to the wall.If your wall is flimsy use the whole sheet. Attach this so it spreads to at least two of those metal inner studs you spoke about. These usually are on 16 inch centers. Then mount a piece of 2x6 or 2x8 . Make this at least a few feet long and screw and glue or bolt this to the plywood at the height of of the extruder. You should use at least 8-10 long screws for this that will go thru the 2x8 and penetrate the 3/4 plywood .Mount the Scott Creek to the 2x8 and start having fun.
I have a Scott Creek and a Brent myself.
Just remember the kids will hang off this thing so it needs to be strong.They also will put hard clay into it and they hang off it so the force to tear it off the wall is large.