M. Roberts
Cast Iron
- Joined
- May 11, 2021
Guys,
I have a job that requires the faces to be flat to 0.0002" over a 10" x 12" x 0.200" thick ceramic plate. To add to the difficulty, there are 60 holes of varying sizes, including a 6.8" hole thru the center. I wasn't able to hit the spec right off of the grinder (yet! I have a few ideas to hopefully hit the spec off of the grinder.), so I decided that I had to attempt to lap it to spec, but I do not have a lap big enough for the job. I looked in McMaster, and found 9"x11" diamond paper; I ordered 4 sheets to put on my granite surface plate...I wet the surface down, and was hoping that they would adhere. I was somewhat successful, but I had issues with the edges not staying down. Luckily, I remembered that I had 24" square Mylar, 0.01" thick. I used the same procedure, wet the surface plate, place the mylar on top, and squish out the air pockets. For this trial, I used a 65 micron diamond slurry, and light to no pressure....it cut, now to see if it is flat...more to follow. Please feel free to chime in...
Mark
I have a job that requires the faces to be flat to 0.0002" over a 10" x 12" x 0.200" thick ceramic plate. To add to the difficulty, there are 60 holes of varying sizes, including a 6.8" hole thru the center. I wasn't able to hit the spec right off of the grinder (yet! I have a few ideas to hopefully hit the spec off of the grinder.), so I decided that I had to attempt to lap it to spec, but I do not have a lap big enough for the job. I looked in McMaster, and found 9"x11" diamond paper; I ordered 4 sheets to put on my granite surface plate...I wet the surface down, and was hoping that they would adhere. I was somewhat successful, but I had issues with the edges not staying down. Luckily, I remembered that I had 24" square Mylar, 0.01" thick. I used the same procedure, wet the surface plate, place the mylar on top, and squish out the air pockets. For this trial, I used a 65 micron diamond slurry, and light to no pressure....it cut, now to see if it is flat...more to follow. Please feel free to chime in...
Mark