Call me crazy but I can't figure out the drawing..
But you have seen my design. I used 3/4" rods for my project..
Here is the cheepest place I found to get rods. Not the fastest shipping but they only charged me 40 bucks shipping for 2 - 60" by 1" thompson and 2 -24 (i think) 3/4" rods.. http://www.qbcbearings.com/RFQ/Defau...e=B612Main.htm
Anyway in my design I'm using 3/4" the shafts are perhaps around 20" each after being cut down (have to double check that) and have 4 bearing blocks. I have sections of 1" and blocks for those from the other assembly I got off ebay. Anyway I'm considering upping my desing to use the 1" to decrease flex. I'd be tempted to stay away from the MM sized shafts and stick with inch ones if ya can (unless ya are out of the US or something)
One other thing I WISH I saw before cutting my rods down.. One design I saw.. Had the rods extending extra length out the top and the guy built a motor mount that clamped to the extra length and between had his love joy. This second clamping section could have been made (for me) at the same time I made the main end plate for the assembly and if the rods extended longer I would have instantly had an adjustiable perfectly aligned motor mount vs having to make the box type I ended up making.
Probably hard to discribe and of course I don't have a link to the picture I saw.. Hopefully that is a good enough description anyway.