(Feb. 16, 2021 6:57 AM)Vtryuga Wrote: Looks like this thread is filled with problems of not enough knowledge on abrasion and wear.
This concept of wear is taught in college in material science and engineering.
First and foremost plastic on plastic contact causes more friction and thus more abrasion and thus more wear. Even metal on metal causes more amount of friction.
The basic concept of wear depends on the surfaces in contact. Usually it is observed that if the materials in contact are the same it leads to more friction and thus more wear
( it sounds counter intuitive but is actually true! A simple experiment to check this is by putting a glass plate in contact with a glass cup; if you compare the friction and adhesive forces between moving steel on glass and glass on glass; we can observe more signs of wear when we conducted the experiment with glass on glass. Why you may ask? The answer is that since the two materials are same the adhesive forces between the two objects increases many times more than when two different materials are used)
Back to the question of Metal Driver caps and Plastic teeth; In theory if everything was kept the same the metal and plastic contact will cause no change in wear( it can be expected to be less due less friction and strain.) Again when using science it is often advised not to follow you intuition as it is more often than not wrong.
Provided the spring doesnt get stronger the force on teeth will remain same and thus no additional warping will occur, that is, it will be almost the same as inn the case of plastic teeth. (sometimes even lower)
However if the spring is stronger then there is an increase in chance of warping and deformation due to the fact that the Youngs Modulus of Plastic( Measure of the elasticity of the material) is not really high. I dont really know what Takara Tomy has advertised apart from the metal on the drivers; if they make the spring stronger only then will it cause problems.
[font="Titillium Web", sans-serif]@[[ NØBØDY ]][/font][font="Titillium Web", sans-serif] As a caution; Friction is the major role in any form of wear. Ignoring friction will lead to wrong answers. [/font]
If I have made any mistake please feel free to correct me.
Some data to back my claims :
coefficient of friction:
plastic-metal
Static :0.25...0.4
Dynamic :0.1...0.3
plastic-plastic
Static : 0.3-0.4
Dynamic : 0.2...0.4
Just beautiful, awesome job! I was about to bring in Archards wear equation but man it is harder than I thought to find experimental k-values so thanks for saving me the time aha