Ive been debating whether or not to upgrade my flimsy 10mm x axis rods to V-rails or the Taz 6 12mm rods. So far I’ve only been able to find 12mm x 500mm (quite cheaply $14) but according to the BOM it’s 12mm x 515mm and sourced through Igus, but my search has been fruitless. Does anyone have any experience upgrading to the Olive/Mangrove specs? Also, would 500mm suffice? I figured that would only be 7.5mm short on each side.
Mcmaster Carr has some that should work fine
www.mcmaster.com/#stainless-steel-alloy-rods/=119c5yw
It seems the closest length they have is 2 ft. I don’t really have a means of cutting hardened steel rods…
That’s natures way of telling you to buy a good chop saw with a metal cutting blade?
I guess I do have a miter saw I can use. Just need to get a blade.
Just thinking out loud, I just upgraded to hardened rods. Given the amount of "extra rod that protrudes from the right of the carriage, does 15mm matter?
I built my TAZ 5.5 (It isn’t a real TAZ 6 because I am still using a TAZ 5 electronics enclosure/RAMBo/etc.) using 500mm 12mm rods and a still have extra rod sticking out. 
They work fine.
A Dremel tool with a abrasive cut off wheel will cut hardened steel. . Look out for sparks and buy like a 10 Pak of disks / wheels. A abrasive wheel is the only thing except a plasma cutter or cutting torch, or a carbide bit in your metal lathe.
Awesome, thank you for the input. I think I will go ahead and get the 12mm x 500mm. Can’t beat the $14 price. Btw… when you upgraded to the 5.5, where is the Z end stop switch located? I can’t seem to find it in the Mangrove pictures.
On the bed right beside the back-left corner of the hot bed. Big metal disc is the top of the switch. 
Ahhh yes, forgot the about mini style leveling…
Put a cut off wheel on an angle grinder and you can do the job. You can true up the ends on a belt sander (with an emery cloth belt) if your cut off job didn’t come out to your liking. I recommend using some cooling water to prevent overheating (though maybe destroying the temper just on the very ends of the parts is not all that big a deal?)
You will not remove the temper cutting just one cut with an abrasive cut off wheel. Most hobby folks own a Dremel tool unlike people like me who have 4 or 5 angle grinders, each with a dedicated wheel or wire brush!
I spent most of my adult life working for a company that makes and heat treats high carbon steel and chrome alloy wire. You can affect the temper with a cut off wheel, but it will generally be very localized - confined to the very end of the piece. As I mentioned, this probably makes no difference in this application. At any rate, I was referring to the sanding operation if someone was trying to clean up an end - again, it would likely be a very localized effect. We mostly noticed it when preparing metallurgical samples for analysis.