Using makerware on mbot

Hi guys, i have the mbot cube dual, i have used makerware as my program of choice, i had to re-install. now the xy carriage slams into the one end, there must be some offset i need to put in to prevent this, In 2014 Giga Faze had put something on the forum to correct this, i cannot find that thread anymore.
I think the standard machines on makerware, the build platform is too big, hence the crashing, can anyone help.