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Bad Munki posted:I'm looking for a handy-dandy chart for cutting threads on my lathe, in particular what diameter I should turn the piece to before starting the threading process. Is it literally just the major diameter precisely for outer threads? Or is there a typical reduction to provide reasonable tolerance? And/or how much smaller for inner threads, in order to provide a typical tolerance? What they taught me in school for metric thread is as follows. External thread: cut the piece you're putting the thread on at -0.05 - -0.1mm of the thread size you're using. So if you're cutting M8 the diameter of the piece becomes 7.9-7.95 mm. Then you put on a chamfer equal to the thread pitch. After that you can cut your thread. Internal thread: drill the piece at M-value minus the pitch, so if you're cutting M8x1, you drill with a 7 mm drill bit. Chamfer is again equal to the pitch. After that you can cut your threads. Dance Officer fucked around with this message at 12:16 on Feb 9, 2022 |
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Feb 9, 2022 12:10
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I have a question about G-code. I figured out two ways to mill a shape out of a piece, but I think they're inefficient. I'd like to know if there's a better/more efficient way of programming the depth. With method 1 I have to write a whole lot of code, with method 2 I give up easy control of the depth that I want to go to. If I wanted to make the depth of the cut -18.2 per example, method 2 would be a lot more involved. method 1 code:code:
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Mar 8, 2022 20:05
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I honestly couldn't tell you if my interpreter has conditionals or looping, and I didn't know there were various dialects. I thought it a standardized programming language. What I can tell you is that I'm Dutch, and the program I use to write these programs is SL, which seems German. It has tons of options for different kinds of machines, the one I program for is a 25+ year old Heidenhain.
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Mar 10, 2022 13:55
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honda whisperer posted:Option b from a fast and loose job shop, our customers detail their inspection requirements in the contracts they make. This is also how the shop I work at does things. It seems to go well for us.
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Jun 11, 2022 12:33
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I've only been in the machining business for a year, but the speeds and feeds you can run face mills at keep surprising me. The inserts we use now can take a feed of 1.5mm/t on stainless. Crazy.
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Nov 22, 2022 15:39
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Rutibex posted:I am just learning the mill and this was a violent explosive surprise to me too. It turns out that a 1/4" endmill can not be run at the same speed as a huge face mill Did you try to run an endmill on the same rpm as a face mill, or at the same cutting speed?
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Nov 22, 2022 19:49
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Rutibex posted:I have finished my final project of Precision Metal Cutting for this semester. Here are all my projects! I learned how to use the manual lathe, milling machine, and surface grinder. I already knew how to use a bandsaw and drill press but we learned those too. You should ship one of those products to me, so I can show it to my boss and tell him it's what I learn in school.
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Nov 30, 2022 21:10
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SkunkDuster posted:How much uptime on a CNC mill is practical for a 24/7 shop? I used to work in a print shop (as in printing things on paper) and I heard once expected average uptime of the equipment was about 66%. The average Dutch job shop gets 25-40 hours of spindle time per machine a week, typically depending on the sort of shop they are. The few that focus entirely on large volume orders get ~100 hours a week on average. As for that LS1 head, it's something my company could make, and I suspect it'd cost you 4-5k to get one made for you.
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Dec 14, 2022 10:30
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That's an interesting question, maybe the lawyer thread will have an answer. My personal guess is that the machine shop that makes the part is in the clear as long as the customer that provided the drawing/cad file didn't mention that they're infringing on patents. It's not our job to look out for that kind of thing, after all.
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Dec 14, 2022 15:31
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There's no insertion point for the wire so my guess is it's two separate pieces.
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Dec 23, 2022 17:18
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Feeling proud of myself right now because I made something really square today, for the first time. (No I was not taught how to properly make something square in machining school)
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Jan 6, 2023 18:51
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It was an aluminium block that had one side facemilled to decent surface roughness (0.4 Ra or so), all the other sides were roughly sawed. I only needed 3 sides square in relation to each other. First step was to clamp the block down in jaws with the milled side face down, hammering it in place, and then facemilling it. Took it out, placed it back in the jaws with the newly machined side facing the unmoving jaw(not sure of the correct termninology in English), put a piece of ~Ø12mm copper bar between the block and the moving/loose jaw, then clamped it down again. Faced again, flipped the block 180°, put it back in the jaws with the bar, faced again. Checked squareness with the machinist square, barely saw anything.
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Jan 6, 2023 19:35
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Rutibex posted:That's how they taught me to make square things in machinists school. Nailed it. How they "taught" (explained it but never asked me to do it) it to me in school was to use regular jaws and skip the wire/round bar. I tried that way at first and the results weren't spectacular.
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Jan 6, 2023 21:16
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I had to use a side mill for the first time this week, on stainless. Tool catalogue recommended Vc 55 m/min, f 1.3 mm/rev. It... did not sound good. At all. Ended up running it at Vc 25, f 0.03. Is it a thing with side mills that they sound like absolute poo poo?
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Jan 10, 2023 21:18
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The side mill in question is 63x2 mm, this one: https://www.hoffmann-group.com/GB/e...00-63X2?tId=444 The material is X5 CrNiMo 17-12-2
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Jan 11, 2023 01:55
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It's for slotting a 10mm deep slot in the middle of a product that's 6mm high and starts at 11mm wide, but goes back to 5mm wide about 5mm in. Also funny that you mention +0/50um, because that's the tolerance I'm trying to hit.
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Jan 11, 2023 04:25
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My shop has to ship parts for anodising regularly. Typically, the customer requests a 18um layer thickness. Whatever the surface finish was before the anodising will show through and determine how it looks, so make sure it's good and shiny before handing it over to the anodising shop if you want it to come out good and shiny.
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Jan 13, 2023 07:50
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All the taps that we use in the shop have what size drill to use lasered on to them, I'm surprised that's not universal.
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Jan 16, 2023 17:40
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Hoffmann Group, I don't think they're active in the US or Canada though.
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Jan 16, 2023 17:50
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It's a good rule of thumb, but not always true. If you predrill an M2 roll tap with a 1.7mm drill like the rule says you should, it's going to cost you your tap.
Dance Officer fucked around with this message at 02:44 on Jan 18, 2023 |
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Jan 18, 2023 02:32
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A solution might be filing it into the right shape with a big, rough file.
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Jan 23, 2023 21:21
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You could try getting a login to the online library, the worst thing that can happen if it requires NDA nonsense or something is that you decide it's not worth it.
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Jan 25, 2023 19:41
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Reading practicalmachinist always makes me think that Americans still commonly use HSS tools, is there any truth to that?
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Feb 1, 2023 21:19
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Bad Munki posted:I need to bore a tapered hole, going from about 20mm ID down to 9mm ID over a length of about 175mm. How the heck do I do this? I do have a lathe, among other things, but that seems the most germane item in the shop. Material is whatever, probably aluminum. You should be able to rotate the piece that holds the toolholder on your lathe. And you should have a separate handle to move it under an angle. Still, a boring bar that goes 175mm deep and has to be less than 9mm thick is probably going to be hard to find, if it exists at all. And with the tool sticking out that much you're going to have serious vibrations loving up your finish.
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Feb 7, 2023 21:41
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If you insist on tapering with a drill, if you want to hit 9mm ID at a depth of 175mm you're going to need a special drill. The deep boring drills at my shop in the range of 9-11mm OD don't have the required length by a long shot. Edit: I should specify that the affordable HSS deep boring drills don't reach that kind of length, the carbide ones do but they cost hundreds. Edit 2: you can of course drill from both sides, why am I making it more complicated than it has to be. Dance Officer fucked around with this message at 01:02 on Feb 8, 2023 |
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Feb 8, 2023 00:53
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Yeah, about the PPE situation, I seem to be the only one in the company to care.
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Feb 10, 2023 12:14
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Good news! I used an HSS endmill for the first time today. It went slow as poo poo.
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Mar 14, 2023 21:15
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I haven't seen truly stupid stuff at my job yet, but I'm typically the person telling others to do things safely. When someone is deburring stock at the belt sander for half an hour without wearing safety gloves or some form of mask. Or when someone crawls into a machine to fix something without turning it off, or at least in emergency stop. Or when the machine is working and the doors are open, and they're not at least wearing safety goggles. Or when they're loving around with the forklift. I just wish they would listen sometimes.
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Mar 20, 2023 17:50
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Are you making it as a DIY project or is this a professional machine? You're going to have to clean your pipes regardless of how mirror shiny you make them. You will have bacterial buildup. Dance Officer fucked around with this message at 00:08 on Apr 25, 2023 |
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Apr 25, 2023 00:03
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Just Winging It posted:Free-machining brass is great, even on my puny lathe you can really take a big girl cut and make it rain golden swarf. I've done some brass lathe work at school, both cnc and conventionally. Never had problems with getting dece finishes with carbide, especially on the cnc lathe.
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May 15, 2023 21:50
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Does anyone in this thread know anything about cad/cam and cnc machining in orthopedics? Having finished machinist school recently I've started to think about how I want to develop professionally and what I'd like to end up doing. I like machining but I'd like to focus a bit more on helping and interacting with people, and I'd like to end up doing complex and challenging machining work.
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Jun 18, 2023 13:27
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I currently work at a job shop (it was an apprenticeship thing where I work 3 days and go to school for 2), and while I have a lot left to learn there I'm probably going to hit a wall at some point. We make a lot of pretty difficult but not really difficult parts, usually a lot of repeat products in small batches as well. The shop isn't very modern in terms of machines, the people doing the programming, the level of automation involved or the tooling used. There's shops around here that do a lot more complex work, but they don't hire people straight out of machinist school to be anything but operators, which I don't want to do. I'd also like to have a social dimension to my work that isn't management.
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Jun 18, 2023 21:03
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I hadn't considered that and I'll look into it. The Dutch situation to my knowledge is that there's typically one reseller for any given software nationally, and one will have to be in my neck of the woods for it to work at all. I have some experience with EdgeCAM and Fusion, and I'll get some experience with hypermill once my employer sends me on a one week course to learn it. They told me that's in the pipeline at the end of last year but haven't acted on it yet.
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Jun 19, 2023 00:50
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I was in school for two years, been working at the shop for just as long. It was supposed to take 3 years but I ended up doing it in 2. The experience with edgecam comes from an evening class I took at school, it was weekly for half a year.
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Jun 19, 2023 01:31
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I enjoy the programming that I get to do, which is very infrequently. Normally I'm given work that's already been made before and I have to use the existing programs. The things I genuinely dislike; the repetitive nature of the work that I do, we normally make <50 of any given part but we've also had orders for hundreds, and that usually falls on me to do. That gets boring. And there's the issue that most of my colleagues aren't exactly interested in any sort of social interaction, or any fun to talk to.
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Jun 19, 2023 04:52
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honda whisperer posted:Sounds like a similar shop but with more new parts, programming, and better people would be a good thing to look for. The repetitive part is going to happen anywhere though. It's all just holes in rectangles. The programs I re run are typically okay. Typically the speeds and feeds are way slower than they can be on aluminium, for stainless idk. The few times I pushed harder with stainless the tools also didn't last as long. It's all done in 3-axis with mazatrol still so if I am finally allowed to go learn hypermill/get taught how to use the 4th axis on my machine I could probably start seriously speeding up machining time with more efficient toolpathing and fixturing.
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Jun 19, 2023 20:29
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Just Winging It posted:I've been turning some brass and running into some issues. It's screeching and spraying chips everywhere, which is my usual experience with it. More worryingly, when running a form tool or parting it's been what I can only describe as 'grabby', trying to yank the tool out of its holder it feels and diving into the material, even with a very light infeed. I know my lathe is a wet noodle, but this feels weird even for it, no chatter, an excellent surface finish, and then, blam, it does that, and I can't figure out why as there does seem to be a discernible pattern to it. My experience with machining brass is that chips flying everywhere is just what brass does. Screeching also happens when you drill it.
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Sep 30, 2023 04:14
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The important thing to remember about metric thread is that the drill size is nominal diameter - thread pitch. You still have to look at a chart but it's pretty simple to figure out your drill size from there.
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Jan 2, 2024 12:16
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It always seemed to me that Titan wants to get people excited for working in a machine shop, learn the trade on the job and earn a big salary, but then my understanding is that in the US it's a very low wage job and people are just chewed up and spat out.
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Feb 17, 2024 06:16
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| # ¿ May 12, 2024 16:55 |
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How much coolant are you applying? In any case, 1000 rpm seems pretty slow to me, for plastic. My experience with milling HDPE is that you have to make sure the tool is sharp, and that you're working at high enough speed and feed, especially if you're drilling.
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Mar 15, 2024 21:06
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