I'm looking at a 10' brake but there's no way I can dedicate floor space to it. Any problems w putting it on casters so I can store it against the wall when not in use?

I don't know why not. Maybe get the ones with wheel locks to keep it put when in use.

Just don't get the cheap ass Harbor Freight casters. I'm guessing that a 10' brake is pretty fawking heavy, and you would want to use good shit. You may have to make a frame to tie them all together, but it depends on the machine I guess.

5" x 2" caster with 2 rows of bearings should work great. Ive seen them bolted/welded to the legs, and seen them with a angle iron frame that the brakes legs sit in. I like the seperate frame setup better. We always chock them with small sand bags on 2 of the casters when using it so the brake doesn't move around.

Take it one step further and make the caster frame with an expanded metal middle section for sheet scraps

Take it one step further and make the caster frame with an expanded metal middle section for sheet scraps

This.

Did something similar to my HF Press brake.
Need to make the legs a bit bigger gets toppy w/out the tray at bottom full though.

What kind of brake is it and whats the tonnage?

Do you do any full capacity or fast ram speed operations?

Press brakes really like to be level and secure to the floor. They use the floor for support in high stress bends.