Robot moving sluggish, slow or not at all
Make sure that all 4 of part D13 are inserted correctly onto main module (see image below)

Wrong orientation will cause friction on the tread, resulting in sluggish slow movement.
Make sure all the batteries are new and facing the proper direction.
***Note: If you need a replacement part you can order it online here, Replacement Parts or fill out the warranty form in the back of your manual and send it to:
Email: info@owirobot.com
or
Fax: (310) 515-0927