I like that tensioner for a new carriage design. Regarding the belts going slack, I noticed that my second printer's belts were stretching on the first few prints. It may just be normal with some belt material. My first printer's belt material came from Open Builds, and it didn't seem to stretch nearly as much. I have no idea if one or both have kevlar or other reinforcements.
I pried the hotend fan off yesterday, and re-glued it about 3mm above the effector plate. A little blue tape to fill the gap at the base, and it is now turning much faster. With all of the problems I have been having with getting magnets to stick, I did not want to break it free after getting it to stick looking for the sweet spot where it didn't interfere with the fan motor.....
I pried the hotend fan off yesterday, and re-glued it about 3mm above the effector plate. A little blue tape to fill the gap at the base, and it is now turning much faster. With all of the problems I have been having with getting magnets to stick, I did not want to break it free after getting it to stick looking for the sweet spot where it didn't interfere with the fan motor.....