Step 1
nCreate a box any way you want. Make sure the all the segments are set to 1.
nNow make it down to a size that is allowable by There and suits your needs. Then zoom in to it to get a better view.
nThe max dimensions for this type of object are 10.00 by 10.00 by 10.00
nWhen building always try and leave a little head room for each dimension so it won’t cause problems when you export it since sizes sometimes get rounded up.