Hi Matt
No, it is a PITA!!! There are no clear instructions for the iteration 2 and the thing is, there are so many different parts that the instructions would change so frequently! The thing is, that when you look at the i2 Prusa, it says a positive as better documentation!!!
Unfortunately, I too struggled like hell to make sense of all the parts I had whilest looking at the manuals for the original Prusa. I`m very confident that I`ve put mine together as I should have so best thing you can do, is download:
http://garyhodgson.com/reprap/2011/03/prusa-mendel-visual-instructions/ ...and use the photos on here and the web to see the slight changes. Notice things like the threaded rod for the cross braces under the bed are held at the TOP of the bar clamps rather than dangling from the bottom... small little things like that!!
The biggest changes are the bed. I presume you`ll be going for a heatbed right (at only £13 extra, you would be crazy not to as it is a PITA without, and instead using blue masking tape and trying to rip your parts off!), basically you just mount the heatbed pcb on 4 screws on the ply or MDF bed.
Regarding material. I used 6mm ply and it has warped due to the heat of the heatbed. However, if you use thicker, your increasing the weight. These things move at quite a fast rate (and still take ages to print!!) and the bed has to be pretty light or it`ll struggle. I`ve seen someone try 3mm aluminium sheet and quickly changed it because it was too heavy. People seem to be having luck with some sort of perspex... I`ve forgot the name, it isn`t very expensive but it looks nice, is fairly light, rigid and doesn`t warp with the temp of the heatbed (60-100 deg C about 6-10mm above the bed) . I`ll try and find you the name of that material as I`m going to pull my machine apart in the next weeks and make a few changes - replacing the ply for this will be one of them.
Good luck with it.
Chris
couple of questions. Did you manage to find a set of build instructions specific to prusa iteration 2?. Every set I can find show two plates for y axis whereas iteration 2 and yours only use upper plate and mount belts to lower side of it. Also what thickness did you use for this plate? I'm thinking 9mm MDF but maybe 12mm would be better?.
Cheers
Matt