sphere plunge grinding

[rickyrobbi]

Hi everyone!!!!
I have a problem.
I have to grind a semisphere on a conventional grinding machine.
I use a special dresser unit to profile the wheel and i don't have any geometrical problems.
My problem is the finishing that is not very good because the grinding operation is made in plunge. I need to reach 0.2-0.3 Ra.
Can anyone help me?
thankyou in advance
Riccardo

 

[saberblue]

Have you confermed that the grinding wheel currently in use is capable of producting the desired finish? Will the material in it's current condition allow you to achieve the desired surface finish?

To answer these questions you will need to talk to your wheel supplier. If the basics are in place you need to work thru one or more of the many check lists.

good luck

 

[twingrip]

After you have checkout what saberblue suggested you need to assess the speeds and feeds of your plunge (what type of machine, centerless or Micro-Centric). Importantly, you need to assess the speed at which you dress the grinding wheel (slower is better), use a single point diamond, how much stock are you removing before you finish, on shperical rollers your finish pass is typically .001 to .00015", you migh experiance wheel breakdown if you are taking more, in which case you can eiher dress before finishing or add a semifinish op, and check the concentration in your coolant 5-6%.