Tool Length offsets and Part offsets
Posted: Sun May 30, 2021 8:40 pm
HI guys, I've just (almost) completed a retrofit from Anilam to Centroid Oak on a large bed mill, and it's been running very well in the early stages, but I keep having a reoccurring issue that I'm hoping someone with a bit more centroid experience can help me with.
I followed CNCSNW's tool length offset procedure(s) http://www.cncsnw.com/OLEM.htm and I have sort of stuck with Method 2. but I have an issue where, sometimes, it won't get the offset right no matter what. for example: I crashed a drill this morning first thing after carefully setting the length offset and the part offset had been set (I always set offset #2 as the back left top corner of my vise hard jaws) and I checked the offset after setting my tool length offset off the machine bed as normal, but then during drilling the machine just ran full rapid into the surface of the part. I checked my ossefts and everything was fine, the numbers were negative where they were supposed to be, I couldn't find anything wrong. so I used tool #1 (my dial) and re-dialed in the part, it was spot on, just for checks and balances I checked the length of tool #1, all good. Then I changed drill bit and reset the offset as per normal, then re-did the part offset as per the procedure, but even after re-zeroing the part with the tool in the machine as per CNCSNW's method, now the tool at X0Y0Z0 is 300mm off the top of the part. I'm starting to lose my mind. I had this same problem last week with a tool, and I removed and re-set every tool in the carousel, then everything was fine, I don't want to have to do that every time I add a new tool.
does anyone know what I'm doing wrong and what is the best way to sort my tool offsets? I don't have a touch probe or anything, I just use a piece of shim stock on the machine bed, I keep the same 10 or so tools in the carousel all the time, the only time I change anything is if I have to replace a worn endmill of I'm using a small twist drill in my drill chuck.
I followed CNCSNW's tool length offset procedure(s) http://www.cncsnw.com/OLEM.htm and I have sort of stuck with Method 2. but I have an issue where, sometimes, it won't get the offset right no matter what. for example: I crashed a drill this morning first thing after carefully setting the length offset and the part offset had been set (I always set offset #2 as the back left top corner of my vise hard jaws) and I checked the offset after setting my tool length offset off the machine bed as normal, but then during drilling the machine just ran full rapid into the surface of the part. I checked my ossefts and everything was fine, the numbers were negative where they were supposed to be, I couldn't find anything wrong. so I used tool #1 (my dial) and re-dialed in the part, it was spot on, just for checks and balances I checked the length of tool #1, all good. Then I changed drill bit and reset the offset as per normal, then re-did the part offset as per the procedure, but even after re-zeroing the part with the tool in the machine as per CNCSNW's method, now the tool at X0Y0Z0 is 300mm off the top of the part. I'm starting to lose my mind. I had this same problem last week with a tool, and I removed and re-set every tool in the carousel, then everything was fine, I don't want to have to do that every time I add a new tool.
does anyone know what I'm doing wrong and what is the best way to sort my tool offsets? I don't have a touch probe or anything, I just use a piece of shim stock on the machine bed, I keep the same 10 or so tools in the carousel all the time, the only time I change anything is if I have to replace a worn endmill of I'm using a small twist drill in my drill chuck.