Looking to group source some thoughts on this so that I can form a consensus on how to approach this issue.

I have a Felder FD-250 slot mortiser, I'm making the conversion on it to a square chisel, which requires the square chisel holder that bolts to the motor. It also includes another handle for the machine with pinions and racks for driving the chisel forward.

My debate is in regard to the fence, there is not much of a factory solution available and so I'm considering sourcing cast iron, aluminum or extruded aluminum to build a sturdy fence which will back the part being mortised (along with a sacrificial bit of wood).

In the experience of the crowd, which of the below solutions would be best; all of them are comparably priced.

- cast iron I can source 1" x 4" thick material by 24" long. I have the capability of machining from rough stock to form square sides. I'll then build some arrangement for easy bracketing to the machine. The machine does make this easy by having a ledge and groove around the entire table. This is 24lbs.

- aluminum I can source 1.5" x 4" by 24. It's 15lbs Same deal as above.

- Finally VSCT offers a machined extrusion that looks pretty heavy, only specs I see on it are that it is 48" long. I'm curious if this is a reasonable approach as I can more easily create stops with this but I'm very curious to know if it would actually survive use as a backup for mortising or if it will deflect.

Any of the above will be easy to use, as the guide I create will have a permanently oiled bronze strip embedded and handles to make it easy to move even a fairly heavy bit of cast iron.

Appreciate your thoughts on best approach.