Welcome to the SeeMeCNC Community

i removed the atx power supply from my Rostock max v2 and installed one of the
long power supplys that they sell on there site .

https://www.seemecnc.com/products/12-vo ... wer-supply

well i say installed its wired up and working ...
but i have no way of mounting it that i can see.

Does anyone have any Mounting hardware for these power supplies maybe in STL format ?

thanks ahead of time .

You can use the mounting holes on either the bottom or sides that take M4 bolts of a suitable length. If you use the sides, simple L brackets should work. Either way, you'll probably have to drill appropriate holes in the base for mounting.