Love it! But when the washer is on spin it shakes the whole pedestal and dryer! Help!

The build was pretty easy. Husband did it in a day. But after the paint dried and we out it in our laundry room and I did some laundry we realized that the washer now shakes the entire pedestal violently to the point where the dryer is being shaken so much that it's banging against the wall. We have brand new LG washer and dryer and this wasn't a problem before our diy pedestal. Do you have any modification suggestions?  We really love the project- but we will have to take it out if we can't find a solution for the shaking.