Brick wall for HO train - Tested

Tested - not quite able to print the brick on my printer as it is nearly 7 years , you may have better luck

also see https://www.thingiverse.com/thing:3393734

I changed one of the setting from .5 to .8 and it improved 200% , now trying it at .9

the brick are now printing - have not update the file as still testing