The original's belt attachment was too weak and broke almost immediately when trying to add the tensioner. I have modified it to have a beefier attachment. Use a zip tie to secure the belt by looping it around the block and tie the end with the belt.
I tried adding a little lip to keep the belt from slipping off but it may not work as planned so another method may be needed if the belt is coming off too easily.
I like this model because it is very compact and allows access to the screws to adjust the heater block height for leveling.