- Joined
- Dec 2, 2016
- Messages
- 234
Anyone gotten down to the very subatomic physical interaction with grinding wheels and the metal they chew through?
I'm talking about looking at things like
Q' - MRR
Aggressiveness numbers
Matching Coolant speed to Wheel speed
Chip thickness Radially and along Flanks?
I've played around with excel to give me a look into all these outputs trying to make sense of it all and quite frankly its looking promising. Already I've seen some improvement.
So to give you an Idea I grind Threads roughly 450+ forms of them. I grind them into cold forming dies that are then used on stainless shafts. All in all somewhat frustrating but rewarding work. Trouble I have been having is keeping my form intact some of my root radii are ~.004", and most importantly the burning that occurs along the flanks.
This is nothing new to the gear grinding industry and probably the most occured failure of a gear is that the metal weakend along the flank as it softened from the grinding process.
One thing my "calculator" shows me is the difference of "chip thickness" of a radial infeed on the tip of the wheel to the flank sometimes its a factor of 7, where the flank would have a chip thickness of .00005mm and the radial chip would have a rough size of .00039mm. These chips are obviously pulled squished stretched and spit out but this is just a number to quantify the lengths of arc, wheel speed and feedrate.
Bigger heavier chips result in less heat as the grain is ploughing through the material it needs to make the transtion from elastic to plastic deformation before it shears. Faster wheels result in more rubbing and plowing as it goes through the same cut faster than a slower wheel, resulting in smaller chips and subsequently more heat.
Some of the problems I have is that my forms are so small that a current meter would not help to find that sweet spot when the grains are fracturing.
Ooops time to go I'll continue my thought process later on.
I'm talking about looking at things like
Q' - MRR
Aggressiveness numbers
Matching Coolant speed to Wheel speed
Chip thickness Radially and along Flanks?
I've played around with excel to give me a look into all these outputs trying to make sense of it all and quite frankly its looking promising. Already I've seen some improvement.
So to give you an Idea I grind Threads roughly 450+ forms of them. I grind them into cold forming dies that are then used on stainless shafts. All in all somewhat frustrating but rewarding work. Trouble I have been having is keeping my form intact some of my root radii are ~.004", and most importantly the burning that occurs along the flanks.
This is nothing new to the gear grinding industry and probably the most occured failure of a gear is that the metal weakend along the flank as it softened from the grinding process.
One thing my "calculator" shows me is the difference of "chip thickness" of a radial infeed on the tip of the wheel to the flank sometimes its a factor of 7, where the flank would have a chip thickness of .00005mm and the radial chip would have a rough size of .00039mm. These chips are obviously pulled squished stretched and spit out but this is just a number to quantify the lengths of arc, wheel speed and feedrate.
Bigger heavier chips result in less heat as the grain is ploughing through the material it needs to make the transtion from elastic to plastic deformation before it shears. Faster wheels result in more rubbing and plowing as it goes through the same cut faster than a slower wheel, resulting in smaller chips and subsequently more heat.
Some of the problems I have is that my forms are so small that a current meter would not help to find that sweet spot when the grains are fracturing.
Ooops time to go I'll continue my thought process later on.
