ClappedOutBport
Cast Iron
- Joined
- Mar 30, 2016
All,
I need a few tips.
My work is not a machine shop. I am not a professional machinist, I am an engineer, but I do regular machine work at home. Grinding is not part of my skill set.
Anyways, we produce one product we grind in house. The material is a refractory metal with highly inconsistent hardness, so it's not even worth discussing. (Also proprietary) Our parts started coming out hourglass shaped and I need to fix them.
The part is approximately the 3/32 size diameter. We are removing roughly .010 to make a round finished part. There were some obvious problems I found. For starters the regulating wheel dresser was locked up due to varnished oil (mineral oil coolant). We stripped, cleaned and reassembled it and I dressed the regulating wheel, it was very clearly out after 3 years of minimal-marginal use. My questions are:
Info:
So in the immediate I know I need to:
I know the wheels, coolant, etc may not be perfect, but we made good parts before. I need to get it back to there and hopefully better. Any advice would be appreciated. Thanks, MB.
I need a few tips.
My work is not a machine shop. I am not a professional machinist, I am an engineer, but I do regular machine work at home. Grinding is not part of my skill set.
Anyways, we produce one product we grind in house. The material is a refractory metal with highly inconsistent hardness, so it's not even worth discussing. (Also proprietary) Our parts started coming out hourglass shaped and I need to fix them.
The part is approximately the 3/32 size diameter. We are removing roughly .010 to make a round finished part. There were some obvious problems I found. For starters the regulating wheel dresser was locked up due to varnished oil (mineral oil coolant). We stripped, cleaned and reassembled it and I dressed the regulating wheel, it was very clearly out after 3 years of minimal-marginal use. My questions are:
- The regulating wheel dresser can swivel on it's mount both in an approximately horizontal and vertical offset. I understand the horizontal angle should match the swivel angle of the regulating wheel spindle. Does the vertical angle matter much? I leveled it out as best I could, but I only had a painted surface to level to. Or is there another way?
- The diamond can be offset. I understand this to be half of the work diameter. Above or below?
- The top slide has an angle adjustment. Do I set this to the arctangent of the diameter delta divided by the wheel length? I.e., .095 degrees? Or leave it at zero?
- How close does one get the blade to the work wheel? What is the general procedure to setting the top slide vs bottom slide? What is the general infeed procedure for setting up to a new diameter?
Info:
- 6" width wheels I believe. Unsure on diameters. Guessing 12 and 8". No data on grit or material.
- I believe the machine is an Supertec STS-C 1206 Supertec
- Very narrow blade, probably 24 or 30 degrees. The blade holder has been cleaned and readjusted, but I don't know if correctly. Nobody here has formal training.
- Regulating wheel angle: currently 2 degrees.
- Dresser angle: 0 degrees
- Diamond offset: None
- Top slide angle: 0 degrees
- Mineral oil coolant.
- Parts are ~3/32 x 3
- Desired stock removal is ~10-15 thou, one pass to finish.
- Parts may have a small tit running down the side, up to .005, but this is generally removed beforehand.
- Tolerance is .001 on the diameter.
So in the immediate I know I need to:
- Adjust the dresser angle to match the spindle angle for the regulating wheel.
- Adjust the diamond offset to the part height.
- Inspect the blade holder to determine the part height.
- Inspect the blade guides for straightness.
I know the wheels, coolant, etc may not be perfect, but we made good parts before. I need to get it back to there and hopefully better. Any advice would be appreciated. Thanks, MB.