I have 8' long pieces of small/thin aluminum extrusion that I need to route some notches in relatively accurately. Can any of you clever folks give some advice on how to hold these down firmly but not have a lot of fixture building. I'll also need something that is relatively quick to quick to change.

Thanks.

without a specific picture, I can not give specific details!
I have used a base plate, with a track milled in it to align the part, and strips the same length as the parts with equally spaced holes to clamp the part on both sides.
The 1st mill pass cut the strips and the part and the plate, then on the 2nd part the milling was only done on the parts.

If you press a little dowel pin in the plate at the end of the track, then all the parts will stop in the same place!

I hope this helps!
Eric

It's a little L-channel and I just need to mill slots into one leg about every inch but I also need to mill a little off the edge so the cut is continuous (over, in, over, in, etc). I really need to hold the part on one side only and the part I'm not coming up with an elegant solution on is how to hold in both the horizontal and down position at the same time without the piece chattering on me.

Make a long fixture using wood or plywood.

As Geof said - use MDF or whatever, then route it to a shape that suits the extrusion and you will have an accurate fixture that's aligned to your axii, cheap and ready to go.

Scott