Among the badminton teaching videos I have seen, Li's online class should be the most detailed explanation. Basically, "what to do, how to do it and why to do it" is very thorough, which is very suitable for review and consolidation. This is better than the on-site teaching experience of many resident coaches.
Competitive hardware requirements:
Badminton should have 16 feathers fixed on the ball support, and the feathers are 64-70 mm long, but the length of each ball's feathers from the support surface to the tip of the feathers should be the same. The top of the feather is round, with a diameter of 58-68 mm, the diameter of the ball holder is 25-28 mm, and the bottom is round. The badminton weighs 4.6-5.5 g. ..
Non-feathered balls should be made into skirt shape, and the quality and performance should not exceed 10%. Badminton should have 16 feathers fixed on the ball support, and the feathers are 64-70 mm long, but the length of each ball's feathers from the support surface to the tip of the feathers should be the same.
The top of the feather is round, with a diameter of 58-68 mm, the diameter of the ball holder is 25-28 mm, the bottom is round, and the weight of the badminton is 4.6-5.5 g. The ball made of non-feather material is required to be made into a skirt shape, and the quality and performance should not exceed 10%.
Refer to the above? Baidu Encyclopedia-Badminton (Sports)