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Ambrose Burnside fucked around with this message at 02:46 on Oct 27, 2021 |
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Oct 27, 2021 01:06
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NewFatMike posted:Psh, like nobody has put a piece of stock in their mill spindle and a cutting tool in their vise before Just call it an inverted VTL and double your quote because you had to use such a specialized machine tool.
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Oct 27, 2021 02:33
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biracial bear for uncut posted:Someone once told me the definition of a good machinist is one that still has all of their digits after 5 years full-time working with machinery. The guy from whom I learned to run a lathe told me that if you cut yourself on the swarf and it hurts then you're a dumbass, but if you cut yourself on the swarf and don't notice until you reach for a tool and leave a bloody handprint, you're an expert.
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Oct 27, 2021 03:47
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conversely i was reminded that a lot of tried-and-true old hand professionals still eventually end up intimately entangled in a lathe chuck's workpiece because they got lazy or showed up on monday still a little drunk. those guys just don't end up on the Wall of Shame out of deference; the new guys who gently caress up absolutely do e: Ambrose Burnside fucked around with this message at 21:13 on Oct 27, 2021 |
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Oct 27, 2021 05:37
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No offense but it kinda sounds like you made sure one of the swiss cheese safety holes was lined up to allow a future tragic accident.
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Oct 27, 2021 16:50
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I think there's a difference between a mistake and a systematic issue and the two things merit different responses.
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Oct 27, 2021 17:10
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Scarodactyl posted:No offense but it kinda sounds like you made sure one of the swiss cheese safety holes was lined up to allow a future tragic accident. tbf, I hade a journeyman machinist that liked to smoke weed on his lunch breaks sometimes. I wouldn't care if he did it in his off time, but he'd come back totally fried and make expensive or unsafe mistakes. I told the owners about it, but he'd been there for years and they just looked the other way and told me to "make do". I had to strategically schedule jobs around his mid day weed intake until we finally let him go during the 2008 crash. It makes me wonder how many concessions worse than that are made now, since covid has made it that much harder to find good employee let alone trained machinists.
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Oct 27, 2021 17:21
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Scarodactyl posted:No offense but it kinda sounds like you made sure one of the swiss cheese safety holes was lined up to allow a future tragic accident. NewFatMike posted:I think there's a difference between a mistake and a systematic issue and the two things merit different responses. yeah, this was ultimately why i didn't come down on him hard like i've had to with other students, he just did not realize he wasn't in a state to be working on a lathe, benzodiazepines are funny that way wrt judgement and perception. it wasn't a pattern of behaviour, just a distinctly-weird Monday 8 AM start. the next day he was so mortified he wouldn't come into the shop, kind of waved me towards the door, and with eyes welling with tears said that he was already clearing his locker out, lol. it still doesn't sit quite right with me to this day to give someone that sort of 'pass' on a serious shop safety issue, have never done so since, but everything I saw from him after that says he knew what a close call he had and that you don't get those twice in life. if i thought he'd had any chance of doing anything like that again I would have filed the report after taking the wrench away from him. Ambrose Burnside fucked around with this message at 21:15 on Oct 27, 2021 |
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Oct 27, 2021 21:11
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rad daddy o posted:tbf, I hade a journeyman machinist that liked to smoke weed on his lunch breaks sometimes. I wouldn't care if he did it in his off time, but he'd come back totally fried and make expensive or unsafe mistakes. I told the owners about it, but he'd been there for years and they just looked the other way and told me to "make do". It would be a lot easier to find good machinists if the profession paid decently. The story of the trades, really. The lab I work at hired a refrigeration service company to do some brazing side-by-side with me the other week, and during the course of talking, the dude mentioned he was a "beer at lunch" kind of guy, and then proceeded to go for lunch at the place he said had good beer. Afterwards, I requested we contract with a different company if we do this again...
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Oct 28, 2021 03:16
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I had a dream once where I popped a couple advil before heading into the shop. My boss asked me if I was on drugs, and then sentenced me to death by hanging. By getting pushed off the top of one of the Haas machines.
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Oct 28, 2021 04:22
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Karia posted:I had a dream once where I popped a couple advil before heading into the shop. My boss asked me if I was on drugs, and then sentenced me to death by hanging. By getting pushed off the top of one of the Haas machines. I'm about to hang myself from one of the Haas machines at our shop. Damned things are always breaking down.
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Oct 28, 2021 13:42
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Karia posted:I had a dream once where I popped a couple advil before heading into the shop. My boss asked me if I was on drugs, and then sentenced me to death by hanging. By getting pushed off the top of one of the Haas machines. Had to be a UMC750 or something, right? Are the TM/VF machines even tall enough for that drop to kill you?
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Oct 28, 2021 13:46
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biracial bear for uncut posted:Had to be a UMC750 or something, right? Are the TM/VF machines even tall enough for that drop to kill you? MDC. Pallet changing vertical, predecessor to the MDC-500, which was predecessor to the DT-1. Probably the least reliable machine I've ever worked on. We had the prototype, serial 1. It was also their prototype for the highspeed toolchanger that they put on the SS machines. If you toolchanged at 100% rapid it would throw the tool.
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Oct 28, 2021 22:09
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Hell, that sounds like the Anderson America Stratos router at my current job.
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Oct 29, 2021 02:29
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Karia posted:MDC. Pallet changing vertical, predecessor to the MDC-500, which was predecessor to the DT-1. Probably the least reliable machine I've ever worked on. We had the prototype, serial 1. It was also their prototype for the highspeed toolchanger that they put on the SS machines. If you toolchanged at 100% rapid it would throw the tool. Cuts tool change times in half!
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Oct 29, 2021 02:46
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Hey cnc thread, is there anyone who might be interested in cutting me a simple ring spacer out of some .5" black hpde/acrylic, something like 9" ID 10.5" OD? I was going to buy a cheap plunge router to do it myself, but being a 1 off I figure I'd ask 
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Nov 19, 2021 07:16
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Maybe try Send Cut Send? I know for sure they do UHMW parts.
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Nov 20, 2021 18:01
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Google Butt posted:Hey cnc thread, is there anyone who might be interested in cutting me a simple ring spacer out of some .5" black hpde/acrylic, something like 9" ID 10.5" OD? I was going to buy a cheap plunge router to do it myself, but being a 1 off I figure I'd ask I hit you up in PMs. babyeatingpsychopath fucked around with this message at 17:24 on Nov 21, 2021 |
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Nov 21, 2021 16:18
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Got my lowrider put together, doing some testing
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Nov 25, 2021 00:05
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Pen testing, a classic! The diode laser I've been eyeing now has an air assist version and an enclosure with a fume extractor hookup The laser: https://ortur.net/collections/laser-engraving-machine/products/ortur-laser-master-2-pro-s2-laser-engraving-machine-10-000mm-min-24v-2a The enclosure: https://ortur.net/collections/optional-parts/products/ortur-laser-master-2-pro-metal-enclosure It's got a rotary attachment, too, so I'm pretty excited about that. I'm working on my CNC room as my winter project, I might make some progress on that this holiday week
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Nov 25, 2021 01:50
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Well, after getting a face full of chips more often than I really wanted I ended up printing plugs for the fixture plate I made.   They actually turned out better than I expected and seem to be watertight when screwed into the plate. No coolant seems to make its way into the holes now and it can be blown or washed off with no issues. They are printed in PETG so hopefully won't dissolve in the coolant.
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Nov 27, 2021 23:31
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drat, those ended up being nice prints! My PETG often ends up being stringy.
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Nov 28, 2021 20:31
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Lowrider update, it works! Used it to cut some more precise parts for itself
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Nov 28, 2021 22:35
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Question: how do you keep records of the jobs you run? Speeds, feeds, workholding, tooling, toolpath nitty-gritty, pitfalls, mistakes... I learn so much every job I run and forget so much in between, I'd love some way to keep track of it all. I'm curious what folks here do about this.
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Nov 29, 2021 07:14
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HolHorsejob posted:Question: how do you keep records of the jobs you run? Speeds, feeds, workholding, tooling, toolpath nitty-gritty, pitfalls, mistakes... I use whatever passes for a Setup Sheet function in whatever CAM package I'm using at the time and make notes, then go back and update whatever passes for a tool/operation settings database in said software.
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Nov 29, 2021 18:11
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I use a notebook and photos for work holding and setup type stuff. I used the mastercam tool library and defaults to store a lot of speeds/feeds/programming details with tool definitions per cutting tool/material and it worked ok, I'd supplement it with an excel document that I'd keep extra stuff in. I was mostly able to standardize my cutting tools across jobs so it didn't take much to keep speed/feed/depth/width notes on hand and programming was pretty quick with that. Setup sheets are also super handy and a good way to take notes as you run the job and then either go back in and update like BRBFU said or I would just tape them in my notebook and use them as reference, I usually ran small enough qty of parts that I wouldn't adjust programming after the first run unless it was out of tolerance. I like to do a save as of CAM files when I export so I always have the as-run program archived to keep track of things.
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Nov 29, 2021 21:20
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HolHorsejob posted:Question: how do you keep records of the jobs you run? Speeds, feeds, workholding, tooling, toolpath nitty-gritty, pitfalls, mistakes... I've managed to model most of the vises I use in fusion so they get baked into programs. I'll design fixturing under the part too so just reopening the program will have a guide to what I did last time. As for feeds and speeds I've started putting in detailed pre-sets in my tool libraries. So for one endmill I'll have a2 adaptive, a2 finish soft, a2 finish 60hrc, etc. It's taken a lot of time to get working but now that it is I can just pick the tool and have most of the parameters pre set. If there's a weird step I'll stick comments and stops in the program. Either stop then move clamps or a stop and check diameter then adjust offset.
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Nov 29, 2021 22:20
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I had a similar setup at my previous job because our vendors for tooling (and the CNC machines themselves, holy poo poo) provided 3d models that we had in libraries for dropping into an assembly in Solidworks to depict a setup and then either use the MasterCAM plug-in or open the assembly in MasterCAM and program things there and that was a really slick way to do things that fed beautifully into the Setup Sheets in MasterCAM. The management was loving awful at the previous place but god drat I miss the software tools at my disposal there. EDIT: I could build something similar at the current place but LOL getting them to buy tooling is like it's a capital expenditure or something (we literally got a directive to stop using 3/4" end mills when CNC programming things because they "cost too much" vs. 1/2" end mills of the same type--gently caress actual material removal efficiency and runtimes, right?).
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Nov 29, 2021 22:27
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I built or found basic models of the table, vices, fixturing parts I regularly used and mocked up some toolholders etc and did something similar when vendors didnt have full 3D available, it wouldn't do advanced collision checking but once youre worried about the column crashing into the part I'm rechecking stuff anyways because that would be a bad day. Sometimes would be frustrating if I assumed I had a free long er32 collet holder or something and they were all tied up in other jobs and had to reprogram things when I was planning on running the mill but it was worth it all in all. Most machine tool sales companies and workholding companies will provide de-featured CAD if you ask from a work account, Mastercam in SW always drove me mad because any change to the model or assembly would need a re-calculation of all the toolpaths, I'd build it in an assembly and then just export an iges and program in mastercam directly. I was programing and operating the mill so I'd do goofy stuff like program the roughing for a mould with a big finishing allowance for rest machining and start that running while I programmed the rest of the part, so being able to lock toolpaths and not have them change was important to me, it was always stressful if something hosed up and I had to rebuild a roughing toolpath and then know it wasn't 1:1 with the code I ran. This was for jobs where the roughing could be a couple hours of run time and having that productive vs watching the machine was huge for getting stuff done.
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Nov 30, 2021 01:03
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biracial bear for uncut posted:
I spent some time working with the guy at work that orders the tools and going from 1/2 to 3/4 carbide was $80 to $280 per endmill. Our shop rate is $70-90 per hour so I'd have to save just under 3 hours per endmill to break even. Oddly the length and flute count moved the price very little it was all about diameter.
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Nov 30, 2021 04:45
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honda whisperer posted:I spent some time working with the guy at work that orders the tools and going from 1/2 to 3/4 carbide was $80 to $280 per endmill. Carbide tooling cost for endmills is like 90% the weight of the tool. If you can get away with a 3/8" tool, go with god, my son, because you'll blow up 6 or 10 of them for the cost of that 3/4" tool. It's also why indexible tooling is so stupidly popular, you can get 3-4 faces (sometimes 8) out of each insert, with 3-6 inserts per tool, at $15-20 per insert. Doing a cost in carbide per cube of material removed, they're less than half the cost of solid carbide. Downside is it's tricky to shove a 1.5" shell mill into a picket that's 1" wide.
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Nov 30, 2021 08:16
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honda whisperer posted:I spent some time working with the guy at work that orders the tools and going from 1/2 to 3/4 carbide was $80 to $280 per endmill. Right, but when we're machining materials that contain abrasives (literally UHMW-PE that has fiberglass mixed in, in this case), those 3/4" end mills survive long enough to finish a part, where those 1/2" end mills will dull out and have to be replaced before a program is finished (where we're parting off strips that also have full-length slots in them out of big slabs of the stock material). Then it's "Hey we need a program to pick up at this random spot that the tool died at and finish the nest from there" which isn't that big a deal other than being just another interruption when trying to write programs for the next order in the queue. (side note: nobody in the shop can write CNC programs or even really understands how CNC machines work, it's a shop full of button-pushers that have to reference a notebook that tells them how to load/set/etc. everything). They used to buy material-purpose end mills from vendors like Onsrud and those tools would last a good deal longer, but back around 2016 they decided to go cheapest supplier because "all carbide tools are the same" to save $10/tool. Some Pinko Commie fucked around with this message at 12:01 on Nov 30, 2021 |
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Nov 30, 2021 11:59
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That's giving me flashbacks to machining these huge garrolite plates that would quickly polish the cutting edges of endmills. It was an uphill battle to get them to try some material specific stuff. Diamond like coating was the best we found. We still see them every once in a while if you can recommend anything better.
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Nov 30, 2021 13:33
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The diamondy-est stuff you can get, PCD vapor deposition coated carbide or pcd cutting edge in a carbide shank tools. They also rip through aluminum injection casting materials that have high silica content or any other highly abrasive no ferrous materials.
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Nov 30, 2021 16:55
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meowmeowmeowmeow posted:They also rip through aluminum injection casting materials that have high silica content or any other highly abrasive no ferrous materials. Seriously, this is no joke. I've run 7" 20 insert PCD facemills at 8000 RPM, 500 IPM. It is absolutely astonishing what you can do with it. And they last forever in cast Al. I was setting up a new turnkey for a customer, transferring an old process they'd been running onto new machines. Some of the tools they gave me were spare PCD cutters that had been sitting in the rack for 4 years because the original tools had cut 300k parts and were still going strong. I honestly don't understand how PCD tool vendors make money on this stuff: it's pricey, but it's not that much more expensive than an equivalent carbide tool. Then my boss stepped down just slightly too far, the inserts cut like 5 thou into one of the tool steel fixture clamps and they were all shot. That was like $3000 down the drain, and I got to spend another hour aligning the new inserts.
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Nov 30, 2021 22:07
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I suspect the UHMW-PE component of the abrasive material I'm talking about is why we don't invest in more PCD mill tooling. I mean, they bought one indexable face mill that they buy inserts for that I use as much as I can when it can fit (it's 2.500" diameter), but some of the things we make also require a lot of narrow slots/holes that they typically don't make in the length of cut we need/which will get the chip evacuation we need to prevent re-welding of the chips.
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Nov 30, 2021 22:15
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Brazed PCD tools often look like router bits with long straight flutes and come in pretty long LOC and as its a brazed tool it's naturally a relieved neck cutter and you can get them in long shanks for deep cuts. You still might have chip evac issues but if it's stuff you can do with a normal endmill you can probably find a PCD tool in the same dimensions that will work. The real wild ones are when they grow (god knows how) a helical vein of diamond in a carbide core and then grind helical flutes into the cutter so the cutting edge and primary/secondary reliefs are in the diamond but the main depth of the flute is in the carbide. They look a lot like a normal endmill but apparently demolish aluminum, I didn't see it in person but our usual.machinenvendor sells makinos and did a MAG6 install for an aerospace shop and said they'll push 3" PCD endmills at 30k rpm as fast as the machine can run it, like 800-1000ipm. Full load on a 125hp spindle...
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Dec 1, 2021 05:59
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meowmeowmeowmeow posted:push 3" PCD endmills at 30k rpm as fast as the machine can run it, like 800-1000ipm. Full load on a 125hp spindle... Coolest thing I've read this morning for sure.
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Dec 1, 2021 16:56
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The makino mags are super cool machines, the photos the guy was showing me of the install were wild - they built a new building for this machine cell, the foundation was poured with a giant pit for the machine base so it was level with the floor, had something like a 10 pallet pool for the machine with 6m x 2m pallets, the works. He couldn't say anything about who it was for or where but I assume it was an aerospace supplier for Boeing as I'm in the PNW and they're a Washington based machine vendor. Some fun videos of the MAG: https://www.youtube.com/watch?v=YkbkpUBD4E8 https://www.youtube.com/watch?v=8LlUtyRa-Pg
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Dec 1, 2021 19:01
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Can anybody recommend a decent all-round resource for tool design/tool geometries? one of my ongoing projects is short-run custom rotary tooling cast using low-melting Matrix tooling alloy, so far I’ve cast custom d-bit reamers intended for soft materials like wood and plastics that actually use the matrix alloy for the cutting edge, to shockingly-acceptable results, but this concept gets much more useful if I embed carbide cutting inserts in the casting molds and cast them in place (the Matrix alloy doesn’t get hot enough to hurt the inserts) to produce composite tools with a proper hard tooling material for the working faces. The locating and orientation of an end or face mill insert is much more involved than the grind on a simple D-reamer, of course, and I’ve never attempted to design a multi-tooth cutting tool from scratch before. I guess I’m looking on a good primer on all the geometry variables and what applies when, spanning various types of cutting tool; I’m already generally familiar with the rules when it comes specifically to, say, grinding a HSS single-point lathe tool, but the finer points of insert-based rotary tooling is not my forte.
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Dec 1, 2021 22:07
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