Missing part for my engine

[DOC123]

Dear All
I am currently making a PMR Mill engine 3A as I am describing in this thread.
http://www.homemodelenginemachinist.com/index.php?topic=11442.0

I seem to have misplaced the bit of brass that is to be used to make the cross head. It is 3/16" thick and 3/4" square. I don't have any other brass that I can substitute and don't really want to buy more bar stock for this little piece as I have no local supplier and all of my metal has to be mailed.
I have steel, aluminium and cast iron of a suitable size to make the piece. The cross head slides in an aluminium track visible in the first pic in the above thread.
I thought that using al on al probably isn't a great idea.
What would be the best metal to use?

Thanks

 

[gbritnell]

From what you have available I would go with the cast iron. Anything other than aluminum on aluminum although the cast aluminum in the kit is a different composition than using bar aluminum.
gbritnell

 

[jonesie]

i also would go with the cast iron,just make sure you have a good slip fit and that you break all the shape edges and corners,and i would emery paper it smooth and it should work fine. i wold also make sure you do not have any sharp corners in the casting. good luck. jonersie

 

[rleete]

Contact PMR. Chances are, they'll send you a new piece for free, or maybe a small handling charge.

That's one of the benefits of dealing with a good company - they'll do quite a bit to make sure you are a satisfied customer.