I found out that the BN-1 has a bit of.a design flaw where the front wheels will pick up and deposit any hair on the floor inside of its gearbox. This hair gets stuck to and wraps around the leg gears which could cause problems. In this guide I will show you how to easily clean the leg gearboxes, removing any hair or dirt.
First remove the inner screw of the paw attachment, then use your thumb to push the side of the paw up and free (it might take some force to get it to pop off).
The leg has 4 screws holding the shell together - remove them. Please note, depending on the screwdriver you have, it may be difficult to remove them with the main body shell on.
When you take the outer leg shell off you should see the gears and motor. As we can see in this BN-1, the leg has cat hair stuck to the gears and human hair wrapped around the pinion gear. To remove this I used a Q-tip to wipe away the cat hair and tweezers to pull the human hair from the pinion gear. You can also take all of the gears out and wash them in dish soap, but if you do its advised to reapply lubricant to the gears.
If you aren't sure how to replace the gears, please refer to the image above that shows the cleaned gear array. ^