I ran 2" conduit under my slab and have run my 110 and 220 wires through the conduit. My original "plan" was to use a type of anchor to mount a 3 foot 4x4 and run conduit up the 4x4 to a box. But I"m concerned that will be a bit wobbly. So I thought about simply using conduit and having it much closer to the floor -- like 4-6 inches off the floor. it will be a double gang box with 110 and 220 both in the box.
Any good ideas on how to mount that so it's not too shaky/wobbly?
Thanks!