huskermcdoogle
Stainless
- Joined
- Nov 11, 2005
- Location
- South Texas
It has been a long week... Been having some trouble with a few parts on our pallet system. Can't seem to tap a hole to save our lives. In fact more specifically... 32 pitch (or for those on the other side of the pond .8 pitch). Scrapped a few parts, though thankfully haven't shipped any bad product, and none of the castings were particularly expensive... I figure since this has been haunting me for a little over a week now I would start a thread about it just in case I ever get all the way to the bottom of it, maybe it will save someone some frustration. It will be written down on this handy dandy forum for someone to stumble upon and hopefully will help someone to come to an "AH HA!" moment.
A little history, we got in a ten pallet 500mm Mori Horizontal (used) about a year and a half ago, and have been setting up part after part after part on it, so on so forth. In fact now it is backed up pretty bad, we have about 17-18 pallets set up with jobs and are playing musical pallets into and out of a pallet pool
. Sometimes I don't know what way is up. Thankfully we have a good number of spare pallets sitting around. And still have a fair amount of room left in the tool cab (just offloaded about 60 to another machine otherwise would have been pretty much full).
Onto the good stuff. So weekend shift is running three or so hot jobs and ends up breaking a tap at the end of Sunday afternoon and hands it over to B shift who starts on Sunday. B Shift goes ahead and runs 4 or so bad parts parts before the decide they need to put some attribute gauges on a part (2 hours into the shift now...) So they no set the job and continue to run the other two jobs. Not an issue here luckily as this was the only job in the machine with an 8-32 thread. So I get in Monday and the bossman says to me "Hey we broke a tap on little whatsyhosey, and so an so didn't check parts yada vent vent yada yada".
So I go check it out, pin a hole to check pre drill size (form tap in cast aluminum), and put some other gauges on the part to try and get an idea of why the tap broke. Fumbling around I find the 6-32 sti on the side is a little loose, though not really out of spec, and same goes for the 4-40 threads, but they tend not to be perfect all the time as I have the tap and drill hanging out about six miles in Ritmar holders for clearance purposes, but they do make tapped holes in spec. Nothing is sticking its head out there and saying, "Hey look over here, I broke the tap!". So I grab a new tap and pop it in there, put in the new length offset, call up the job, load the fixture, scrap the bad parts, instruct the operator to slam a gauge on the part before he sends another one in there, and go on with my day, processing another job for this already over booked machine.
A few hours pass by and the bossman comes into my office with a part and a thread gauge, "Yo brother man, a few of these are coming in oversize.". Hands me the part to look at and proceeds to say that a few parts from before the tap breakage have the same hole oversize in them. So I gauge the part and find that you would be hard pressed to fit a fart between that no go member and the part. But none the less it is indeed oversize, so we shouldn't ship it. Cursing under my breath, I go online and order a slightly smaller d number tap, just in case I can't get to the bottom of it.
So now rather annoyed as a simple job has now started to occupy a significant amount of my day I head back out to the machine to grab the tap out of the cabinet and go check it in the presetter, just in case I missed something. Tap looks perfect, though has more traces of buildup starting on it that I would like to see after only have tapped 8 holes. So I put it back into the machine and proceed to reduce the speeds and feeds by about 30%, and cut another part. At this point it has my full attention, so I stick around the machine and do some housekeeping / steaming about the mess that the load station area is, organize some tools and track down some that are missing though will need to be there for the night shift to run, and bark at the operator to stop being lazy and catch up on deburr. Ok, I admit, this is not done in a barking manner, operators aren't trees... more seriously it is not my place to be reprimanding operators as I am not the shop foreman, just the ME, but I will drop subtle and politically savvy reminders as to why they are in the building from time to time, and get them started on something different to alleviate the metal boredom which does nothing but breed lazyness. Anyway, about not the part has come out and I check some parts, no go doesn't really go, so as we are hot for parts let them rip on it.
Next day, I get into work and the bossman isn't in, but his business partner is, which is not normal for this time of day. He greets me and one of my coworkers and proceeds to tell me the cell is down again, though this time because of a different part. And the bosses wife is having her baby, so we won't see him today. Our Q/A tech proceeds to tell me that the part got ripped out of the fixture, but they can't find all of it. Immediately my heart starts to sink as I picture an 8" x 8" x 2" chuck of material wadded up in the chip conveyor. The primary chip conveyor is great for removing chips, but cannot I repeat cannot handle any solid over about say a 1" cube. Otherwise it will bind. So I hike out to the machine and put some eyes in it. Conveyor will run, doesn't seem to bind, can't see anything really, fixture looks in tact (sigh of relief), so I keep looking for the part, finally I move the z axis and the part falls from some crevasse onto the Ball-screw / mechanical tunnel on the back side of the pallet. I get the part, and proceed to kick that pallet out, and go about checking my tools that are used on the job to make sure they are all still present and able to remove some aluminum. No casualties. Looking that the pieces of part left I find that the op10 was misloaded and therefore wouldn't clamp properly into op20, leaving less than 1/2 of the clamps actually holding the part. So I park that job for the time being and go about the rest of my morning, letting the machine chug along on other just as hot parts. So about an hour later, the operator comes and gets me telling me that he broke another tap. This time it is the 6-32 STI, and for some reason I didn't have a spare, so I had to shut that job down. At this point I have now created more scrap than I have good parts on this job in the last three days. Very, very frustrated I order some spare taps, and go to assembling some fixtures that I have been neglecting for a week now. That afternoon the bossman comes in to check on us, (mostly he just can't go a day without stopping in at work), after congratulating him on his second child, I proceed to give him the rundown on this machine, he tells me to throw in the towel and just have our weekend guy run the one job till it stops, and whoever gets to running off another part on the job that had the part ripped from it will get to it later this weekend (the only people who will do that are me and him). So I went home, figuring it would be me.
So I go in the next morning and decide that since there is still another 10 hours of parts left on the single job that I can let it slide till Sunday, and get deeply involved with a programming project I need to get done, and have been getting too distracted to be able to finish. So without any distractions minus the occasional visits from the weekend guy, I slog through the programming and a few other office "chores". Realizing that I have now just put in 10+ hours more overtime in, go onto the afternoon and evening projects at home.
So I wake up Sunday sick as a dog and decide not to go into work, as I can't really leave the house, and can't really stomach anything. Afternoon rolls around and the bossman calls me to ask if there was anything I was particularly worried about when restarting that job. I tell him what to look at and get back to sleeping off the sickness...
Monday rolls around and I feel better though still have to make more frequent trips to the restroom than I would like. Nothing like not being 100%, but having too much to do, where sitting at home will actually not help because of the stress from not being able to get your work done. I get into work and find that B shift has now loaded a part backwards (didn't know this was possible, now we do). Only lost one tool (picture of it in another post earlier this week). So I get it back together and recommence manufacturing these parts, just now spend some time loading the parts and working out some new work instructions in preparation for retraining B-Shift how to load this part properly, because there were other quality issues we found we needed to address. Bossman and I now decide that the problem with other part that we were having tapping issues on was due to a bad heat treat batch as we had just started a new bin of parts. We both also agree that our coolant age isn't helping the problem, but need to run some more parts and not waste 150+ gallons of fresh makeup that we just put in the machine. We figured that since it has been going rank for a good two weeks now that it isn't the main issue, not to mention we can still tap just fine on another part which has about 42 M4 holes on.
So we have a solution now. A real sigh of relief, I think we got to the bottom of it. Bad heat treat. Material is too soft, I like simple problems.
Not... Next day rolls around and I am finally getting to setting up the new part which I have been trying to get going for a week now. It's Tuesday, I have had fixtures for a week, I have my program pretty much ready, just need a probing routine, to tram in a column, install my fixture plates, and cut a part. For the most part, I was able to do just this, had a good day, minimal distractions, and only a few time consuming hiccups. I still wasn't 100% feeling good so there were a few moments where I needed to take a break and figure out if I should still be there, but after the moment passed it was back to work again. Five o'clock rolls around and I am just now making chips fly on the part, things went well from the window, only a few small errors caught before execution, and I feel I have a successful fixture design, which with these big flat parts has been a big challenge to be able to hold them without distorting them or having a large section go unsupported, and have chatter problems. This fixture rocked, no chatter whatsoever, part was flat to begin with, and it seems as though I don't have a staging problem, so I may for once actually get planned to print results, not reactive one the fly approval results. Bossman was happy to see the progress, and asked if I had any issues, I told him my goal was to finish the op10 and get home. So after finishing OP10 and doing some quick checks I found the I had a bad galling problem on three of 32 M5 holes on the part. I have tapped many many many M5 holes with this drill and tap combo and based on experience with these castings in the past, I knew it wasn't the drill, tap, or material. Shoot, I guess Heat Treat wasn't the problem. So I went home to think, reconvene in the morning and discuss options with the boss man. This was my free part, so I need to get what I can out of it, every part from here on will cost us if I scrap it, so I need to use other cheaper parts to figure out this tapping issue.
Next morning rolls around, this is Wednesday now, so the boss man and I discuss our options and decide we need to do a pump and clean. So I go about finding the necessary equipment to get it done, and cross my fingers I have enough storage for the coolant and subsequent wash water from the job. Go back to the tote and barrel area and find that there is an almost empty tote and about 4 drums kicking around. I notice that the machine is basically full still as it hasn't been running due to the tapping issues, and lack of time to get other jobs turned on and verified. Doing a quick visual analysis, looks like we will have it in the bag... After pumping for about 40 minutes I am down to the point where I can pull out the tank and start vacuuming it out. I have now pumped out 225 gallons of coolant. I pull out the tank and tip it on blocks to get the remaning coolant to flow to one corner and start vacuuming it out. My tote is now full. We have removed a full 270 gallons of coolant and are now down to a few small puddles. Fast forward through a million distractions, tank scraping, scrubbing, rehookup, partial fill with whamex,rinse machine, run all pumps, pumpout, partial fill with water, rinse and repeat, pumpout and recharge with fresh, run out of coolant (machine 1/2 full) and it is 10pm... Time to go home.
I got in this morning (Thursday) and told myself that I need to finish my part from Tuesday (OP20). I cut the part, and now my M10 threads look like poop. These are cut threads, this makes no sense. No sense at all. These were fine on the op10 before the pump and clean. Ok, well I guess they are little deeper so I will try peck tapping next time... Minor solution there. So I go about setting up a few other jobs, we don't have our castings back from the suspected bad heat treat job, so I can't run those, but I have some time now (not really, just need to get something running...) so I mount up some plates and let one rip. Everything is fine until it comes out and there is what is left of my M5 tap sitting in the part.....
Insert side problem. For the last few months we have had a weird harmonic on this machine, once in a while, and faint, and only during interpolated moves. At first we couldn't point it at anything, but in the last few weeks it has gotten much loader and more frequent, and we now think it is the Y-Axis motor. The Y-Axis has been louder during rapid, and the when the harmonic happens the load monitor is jumping all over the place. But there are no apparent finish issues, and we have been holding location fine, so we don't seem to think there are any major mechanical issues. Once again the harmonic is only during an interpolated move.
So, through this whole thing we were kinda reluctant to think that this motor issues the cause of all of our tapping issues, but in hearing it tap right now, this the most common place where the harmonic develops, even though the axis is stationary, it makes more noise when not moving. So this is where I am at. I am going to get up bright and early, and get the machine prepped for a new motor which will be coming in ups in the morning. That is my day and wish me luck.
Sorry for the diarrhea of the hands here. But it is the best way to get it off my mind so I can sleep. I am hoping that someone out there has some insight to these issues, because if this motor doesn't solve things, I am going to need another lead to track down.
Wish me luck and I will post my findings and edit this post for grammatical errors tomorrow evening.
Husker
A little history, we got in a ten pallet 500mm Mori Horizontal (used) about a year and a half ago, and have been setting up part after part after part on it, so on so forth. In fact now it is backed up pretty bad, we have about 17-18 pallets set up with jobs and are playing musical pallets into and out of a pallet pool
. Sometimes I don't know what way is up. Thankfully we have a good number of spare pallets sitting around. And still have a fair amount of room left in the tool cab (just offloaded about 60 to another machine otherwise would have been pretty much full).Onto the good stuff. So weekend shift is running three or so hot jobs and ends up breaking a tap at the end of Sunday afternoon and hands it over to B shift who starts on Sunday. B Shift goes ahead and runs 4 or so bad parts parts before the decide they need to put some attribute gauges on a part (2 hours into the shift now...) So they no set the job and continue to run the other two jobs. Not an issue here luckily as this was the only job in the machine with an 8-32 thread. So I get in Monday and the bossman says to me "Hey we broke a tap on little whatsyhosey, and so an so didn't check parts yada vent vent yada yada".
So I go check it out, pin a hole to check pre drill size (form tap in cast aluminum), and put some other gauges on the part to try and get an idea of why the tap broke. Fumbling around I find the 6-32 sti on the side is a little loose, though not really out of spec, and same goes for the 4-40 threads, but they tend not to be perfect all the time as I have the tap and drill hanging out about six miles in Ritmar holders for clearance purposes, but they do make tapped holes in spec. Nothing is sticking its head out there and saying, "Hey look over here, I broke the tap!". So I grab a new tap and pop it in there, put in the new length offset, call up the job, load the fixture, scrap the bad parts, instruct the operator to slam a gauge on the part before he sends another one in there, and go on with my day, processing another job for this already over booked machine.
A few hours pass by and the bossman comes into my office with a part and a thread gauge, "Yo brother man, a few of these are coming in oversize.". Hands me the part to look at and proceeds to say that a few parts from before the tap breakage have the same hole oversize in them. So I gauge the part and find that you would be hard pressed to fit a fart between that no go member and the part. But none the less it is indeed oversize, so we shouldn't ship it. Cursing under my breath, I go online and order a slightly smaller d number tap, just in case I can't get to the bottom of it.
So now rather annoyed as a simple job has now started to occupy a significant amount of my day I head back out to the machine to grab the tap out of the cabinet and go check it in the presetter, just in case I missed something. Tap looks perfect, though has more traces of buildup starting on it that I would like to see after only have tapped 8 holes. So I put it back into the machine and proceed to reduce the speeds and feeds by about 30%, and cut another part. At this point it has my full attention, so I stick around the machine and do some housekeeping / steaming about the mess that the load station area is, organize some tools and track down some that are missing though will need to be there for the night shift to run, and bark at the operator to stop being lazy and catch up on deburr. Ok, I admit, this is not done in a barking manner, operators aren't trees... more seriously it is not my place to be reprimanding operators as I am not the shop foreman, just the ME, but I will drop subtle and politically savvy reminders as to why they are in the building from time to time, and get them started on something different to alleviate the metal boredom which does nothing but breed lazyness. Anyway, about not the part has come out and I check some parts, no go doesn't really go, so as we are hot for parts let them rip on it.
Next day, I get into work and the bossman isn't in, but his business partner is, which is not normal for this time of day. He greets me and one of my coworkers and proceeds to tell me the cell is down again, though this time because of a different part. And the bosses wife is having her baby, so we won't see him today. Our Q/A tech proceeds to tell me that the part got ripped out of the fixture, but they can't find all of it. Immediately my heart starts to sink as I picture an 8" x 8" x 2" chuck of material wadded up in the chip conveyor. The primary chip conveyor is great for removing chips, but cannot I repeat cannot handle any solid over about say a 1" cube. Otherwise it will bind. So I hike out to the machine and put some eyes in it. Conveyor will run, doesn't seem to bind, can't see anything really, fixture looks in tact (sigh of relief), so I keep looking for the part, finally I move the z axis and the part falls from some crevasse onto the Ball-screw / mechanical tunnel on the back side of the pallet. I get the part, and proceed to kick that pallet out, and go about checking my tools that are used on the job to make sure they are all still present and able to remove some aluminum. No casualties. Looking that the pieces of part left I find that the op10 was misloaded and therefore wouldn't clamp properly into op20, leaving less than 1/2 of the clamps actually holding the part. So I park that job for the time being and go about the rest of my morning, letting the machine chug along on other just as hot parts. So about an hour later, the operator comes and gets me telling me that he broke another tap. This time it is the 6-32 STI, and for some reason I didn't have a spare, so I had to shut that job down. At this point I have now created more scrap than I have good parts on this job in the last three days. Very, very frustrated I order some spare taps, and go to assembling some fixtures that I have been neglecting for a week now. That afternoon the bossman comes in to check on us, (mostly he just can't go a day without stopping in at work), after congratulating him on his second child, I proceed to give him the rundown on this machine, he tells me to throw in the towel and just have our weekend guy run the one job till it stops, and whoever gets to running off another part on the job that had the part ripped from it will get to it later this weekend (the only people who will do that are me and him). So I went home, figuring it would be me.
So I go in the next morning and decide that since there is still another 10 hours of parts left on the single job that I can let it slide till Sunday, and get deeply involved with a programming project I need to get done, and have been getting too distracted to be able to finish. So without any distractions minus the occasional visits from the weekend guy, I slog through the programming and a few other office "chores". Realizing that I have now just put in 10+ hours more overtime in, go onto the afternoon and evening projects at home.
So I wake up Sunday sick as a dog and decide not to go into work, as I can't really leave the house, and can't really stomach anything. Afternoon rolls around and the bossman calls me to ask if there was anything I was particularly worried about when restarting that job. I tell him what to look at and get back to sleeping off the sickness...
Monday rolls around and I feel better though still have to make more frequent trips to the restroom than I would like. Nothing like not being 100%, but having too much to do, where sitting at home will actually not help because of the stress from not being able to get your work done. I get into work and find that B shift has now loaded a part backwards (didn't know this was possible, now we do). Only lost one tool (picture of it in another post earlier this week). So I get it back together and recommence manufacturing these parts, just now spend some time loading the parts and working out some new work instructions in preparation for retraining B-Shift how to load this part properly, because there were other quality issues we found we needed to address. Bossman and I now decide that the problem with other part that we were having tapping issues on was due to a bad heat treat batch as we had just started a new bin of parts. We both also agree that our coolant age isn't helping the problem, but need to run some more parts and not waste 150+ gallons of fresh makeup that we just put in the machine. We figured that since it has been going rank for a good two weeks now that it isn't the main issue, not to mention we can still tap just fine on another part which has about 42 M4 holes on.
So we have a solution now. A real sigh of relief, I think we got to the bottom of it. Bad heat treat. Material is too soft, I like simple problems.
Not... Next day rolls around and I am finally getting to setting up the new part which I have been trying to get going for a week now. It's Tuesday, I have had fixtures for a week, I have my program pretty much ready, just need a probing routine, to tram in a column, install my fixture plates, and cut a part. For the most part, I was able to do just this, had a good day, minimal distractions, and only a few time consuming hiccups. I still wasn't 100% feeling good so there were a few moments where I needed to take a break and figure out if I should still be there, but after the moment passed it was back to work again. Five o'clock rolls around and I am just now making chips fly on the part, things went well from the window, only a few small errors caught before execution, and I feel I have a successful fixture design, which with these big flat parts has been a big challenge to be able to hold them without distorting them or having a large section go unsupported, and have chatter problems. This fixture rocked, no chatter whatsoever, part was flat to begin with, and it seems as though I don't have a staging problem, so I may for once actually get planned to print results, not reactive one the fly approval results. Bossman was happy to see the progress, and asked if I had any issues, I told him my goal was to finish the op10 and get home. So after finishing OP10 and doing some quick checks I found the I had a bad galling problem on three of 32 M5 holes on the part. I have tapped many many many M5 holes with this drill and tap combo and based on experience with these castings in the past, I knew it wasn't the drill, tap, or material. Shoot, I guess Heat Treat wasn't the problem. So I went home to think, reconvene in the morning and discuss options with the boss man. This was my free part, so I need to get what I can out of it, every part from here on will cost us if I scrap it, so I need to use other cheaper parts to figure out this tapping issue.
Next morning rolls around, this is Wednesday now, so the boss man and I discuss our options and decide we need to do a pump and clean. So I go about finding the necessary equipment to get it done, and cross my fingers I have enough storage for the coolant and subsequent wash water from the job. Go back to the tote and barrel area and find that there is an almost empty tote and about 4 drums kicking around. I notice that the machine is basically full still as it hasn't been running due to the tapping issues, and lack of time to get other jobs turned on and verified. Doing a quick visual analysis, looks like we will have it in the bag... After pumping for about 40 minutes I am down to the point where I can pull out the tank and start vacuuming it out. I have now pumped out 225 gallons of coolant. I pull out the tank and tip it on blocks to get the remaning coolant to flow to one corner and start vacuuming it out. My tote is now full. We have removed a full 270 gallons of coolant and are now down to a few small puddles. Fast forward through a million distractions, tank scraping, scrubbing, rehookup, partial fill with whamex,rinse machine, run all pumps, pumpout, partial fill with water, rinse and repeat, pumpout and recharge with fresh, run out of coolant (machine 1/2 full) and it is 10pm... Time to go home.
I got in this morning (Thursday) and told myself that I need to finish my part from Tuesday (OP20). I cut the part, and now my M10 threads look like poop. These are cut threads, this makes no sense. No sense at all. These were fine on the op10 before the pump and clean. Ok, well I guess they are little deeper so I will try peck tapping next time... Minor solution there. So I go about setting up a few other jobs, we don't have our castings back from the suspected bad heat treat job, so I can't run those, but I have some time now (not really, just need to get something running...) so I mount up some plates and let one rip. Everything is fine until it comes out and there is what is left of my M5 tap sitting in the part.....
Insert side problem. For the last few months we have had a weird harmonic on this machine, once in a while, and faint, and only during interpolated moves. At first we couldn't point it at anything, but in the last few weeks it has gotten much loader and more frequent, and we now think it is the Y-Axis motor. The Y-Axis has been louder during rapid, and the when the harmonic happens the load monitor is jumping all over the place. But there are no apparent finish issues, and we have been holding location fine, so we don't seem to think there are any major mechanical issues. Once again the harmonic is only during an interpolated move.
So, through this whole thing we were kinda reluctant to think that this motor issues the cause of all of our tapping issues, but in hearing it tap right now, this the most common place where the harmonic develops, even though the axis is stationary, it makes more noise when not moving. So this is where I am at. I am going to get up bright and early, and get the machine prepped for a new motor which will be coming in ups in the morning. That is my day and wish me luck.
Sorry for the diarrhea of the hands here. But it is the best way to get it off my mind so I can sleep. I am hoping that someone out there has some insight to these issues, because if this motor doesn't solve things, I am going to need another lead to track down.
Wish me luck and I will post my findings and edit this post for grammatical errors tomorrow evening.
Husker
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