stef_sandoval
Plastic
- Joined
- Dec 3, 2019
Hi, community
Needs some advice on running these similar parts that my company has me running. I'm young and I have experienced setting up mostly small lathe parts, not an expert though. I'm back at my old job and this time I'm expected to run and set up a few production parts that never end. To me there big and more expensive than what I'm used to. Semi-conductor parts for LAM Research. The biggest issue that I and the new crew are having is measuring the large OD's ranging from 10-12 inches. The part is very simple. Face and turn large OD, flip and turn to final length with small OD on the flip side. These parts are somewhat hollow on the inside. We have a caliper, mic, and special gauge made from Dorsey. The caliper is by far the easiest way to measure the part but not precise enough. The mic is hard to handle but every day it gets easier to use. The Dorsey gage is custom and expensive and supposed to be accurate and easy to use. The gage uses a red ruby to make contact on the part and master gage where it's zeroed out and then placed on the part to measure and compare. As the temperature fluctuates inside the shop the gauge has to be frequently zeroed out. The master is the nominal size of my part. Gage says it has an error of .0001. The problem is from what I've been told that parts change size depending on the temperature. The shop has good AC and it gets up to 74 degrees inside. Been running my parts at -.0002 on gauge since this seems to be the sweet spot in order for the CMM in a temperature control room to give me a nominal OD size. It varies but is very close to nominal. On my third inspection of the day, I sent my part to QC with the same reading with a gauge reading -.0002 but my part was .0006 on the high side, .0001 out of spec. I don't understand how the part can grow when the gage is saying the part is good and I've been running similar offsets. Tomorrow I will find out if the part was really out of spec. This is not the first time we have had these issues with QC even though we have an expensive custom OD gauge. Any advice.
Needs some advice on running these similar parts that my company has me running. I'm young and I have experienced setting up mostly small lathe parts, not an expert though. I'm back at my old job and this time I'm expected to run and set up a few production parts that never end. To me there big and more expensive than what I'm used to. Semi-conductor parts for LAM Research. The biggest issue that I and the new crew are having is measuring the large OD's ranging from 10-12 inches. The part is very simple. Face and turn large OD, flip and turn to final length with small OD on the flip side. These parts are somewhat hollow on the inside. We have a caliper, mic, and special gauge made from Dorsey. The caliper is by far the easiest way to measure the part but not precise enough. The mic is hard to handle but every day it gets easier to use. The Dorsey gage is custom and expensive and supposed to be accurate and easy to use. The gage uses a red ruby to make contact on the part and master gage where it's zeroed out and then placed on the part to measure and compare. As the temperature fluctuates inside the shop the gauge has to be frequently zeroed out. The master is the nominal size of my part. Gage says it has an error of .0001. The problem is from what I've been told that parts change size depending on the temperature. The shop has good AC and it gets up to 74 degrees inside. Been running my parts at -.0002 on gauge since this seems to be the sweet spot in order for the CMM in a temperature control room to give me a nominal OD size. It varies but is very close to nominal. On my third inspection of the day, I sent my part to QC with the same reading with a gauge reading -.0002 but my part was .0006 on the high side, .0001 out of spec. I don't understand how the part can grow when the gage is saying the part is good and I've been running similar offsets. Tomorrow I will find out if the part was really out of spec. This is not the first time we have had these issues with QC even though we have an expensive custom OD gauge. Any advice.