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Ambrose Burnside posted:Is it for use on mills as well as lathes? Manual lathes can have an X-axis crossfeed with a 1:1 or 2:1 ratio depending on if they measure 'on radius' or 'on diameter', so DROs offer that dia/rad switch feature for the X-axis to accommodate both regimes. That's what I was thinking, but didn't want to just guess. The only thing that would give a weird 2:1 geardown like that would be if you had it set in lathe mode somehow.
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Oct 9, 2019 00:42
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I had to pretend to be a machinist today and am wondering if the way I did what I did was the best way given the tools available or if there was a better option I didn’t think of. I got a collet for my mortiser with an OD .01” bigger than it should have been to fit my machine. Rather than send it back and wait a few weeks for them to fix it, I asked my local machine shop (that makes huge gears and poo poo and have tons of awesome old ww2 surplus machines) if they could do it, and he said ‘yeah I can but we’d have to set up for it and charge you $150. Couldn’t you just chuck it in your wood lathe and go to town with emery cloth?’ Anyway, that’s basically what I did but used a pretty coarse file followed by a fine file and buffed it up on the wheel. My lathe has a pretty low speed for a wood lathe, and it felt safe enough holding files to the piece. Not really visible in the pics, but the collet is slit so it squeezes the chisel-this let it expand when I chucked it and it was not centered very well in my not very good chuck, but it basically worked. It is definitely a few thou out of round, but it just gets squeezed so I don’t think it really matters. It took about an hour, but I was taking it really slow and cautious because I didn’t want to go too small.   This lathe does actually have a banjo/cross-slide on it, but as out of center as the part was and not having any tooling I figured this was the best approach. Was there a better way?
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Oct 9, 2019 00:45
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Kaiser Schnitzel posted:I had to pretend to be a machinist today and am wondering if the way I did what I did was the best way given the tools available or if there was a better option I didn’t think of. I got a collet for my mortiser with an OD .01” bigger than it should have been to fit my machine. Rather than send it back and wait a few weeks for them to fix it, I asked my local machine shop (that makes huge gears and poo poo and have tons of awesome old ww2 surplus machines) if they could do it, and he said ‘yeah I can but we’d have to set up for it and charge you $150. Couldn’t you just chuck it in your wood lathe and go to town with emery cloth?’ Honestly, if you got the result you wanted and didn't hurt yourself, you did fine. Looks like a creative way to get around the problem, I probably would have done the same.
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Oct 9, 2019 01:06
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That pattern on the inside is quite beautiful. It looks almost exactly like harmonic chatter but I assume it's intentional.
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Oct 9, 2019 02:41
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Looks good! A more elegant solution than when Matthias Wandel cut a morse taper with an angle grinder.
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Oct 9, 2019 08:56
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It came from Redditquote:AITA for underplaying my abilities Obviously there is nothing wrong with declaring excessing overtime, because companies stealing wages from their employees is by far the most damaging form of theft in the country. If you aren't stealing from your boss, you're stealing from your family. However, what do you think about the changes he made to the cycle? is the boss just a moron stick-in-the-mud who's wasting time and money, or is this a case of an engineering student who thinks he's a lot smarter than he is and the machine is going to self-destruct next time he runs his "improved" program?
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Oct 9, 2019 18:49
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Sagebrush posted:It came from Reddit I've seen shops where one dude writes the code and it's his baby. No one else fucks with it, whether he's wrong or right. That said, Redditor dude might have increased insert consumption by 1000%. Or he might have thermally stressed the parts and caused other issues. He paints the story like he's a hero and everyone else is an idiot. His supervisors might be wrong, dude might be right, but I have a feeling there's more to the story.
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Oct 9, 2019 18:59
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It's also not uncommon for operators to run poo poo slowly so they're not constantly loading and unloading, and they have more time to dick around on their phones between parts.
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Oct 9, 2019 19:40
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Methylethylaldehyde posted:That's what I was thinking, but didn't want to just guess. The only thing that would give a weird 2:1 geardown like that would be if you had it set in lathe mode somehow. It’s a c80, and there is a radius/diameter setting if it’s in lathe mode according to the manual. Dunno how that could have happened, but it’s possible I guess.
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Oct 9, 2019 20:38
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Got curious and looked it up. There was a lot of pushback on Reddit so she posted some followup. I'm omitting a lot of self-agrandizement, the person seems full of herself and really obnoxious, but does seem to know what they're doing RE: basic process optimization. If the person is good enough to make all these changes competently without risking a crash, I'd say go for it. But I also wouldn't blame a shop for not trusting some new hire to mess with processes that work well enough regardless of how much experience they have on paper. Overall it sounds like a pretty typical case of a prototype/short-run shop that stumbled into a production job and can't/isn't interested in optimizing processes for repeat jobs. I've seen similar stuff all the time, even in actual production lines. 2.5" hand-resharpened HSS drills in brand new $600k HMCs, anyone? quote:EDIT——————clearing up questions comments and concerns, didn’t realize there would be so many machinist and engineers here so I didn’t clarify much
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Oct 9, 2019 20:50
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Karia posted:Got curious and looked it up. There was a lot of pushback on Reddit so she posted some followup. I'm omitting a lot of self-agrandizement, the person seems full of herself and really obnoxious, but does seem to know what they're doing RE: basic process optimization. If the person is good enough to make all these changes competently without risking a crash, I'd say go for it. But I also wouldn't blame a shop for not trusting some new hire to mess with processes that work well enough regardless of how much experience they have on paper. If it works out, why not? But a good shop should recognize an improvement and reward them for it. Doing it on the sly, regardless of time paid out, presents issues. Chances are the shop is making a bunch of money on it otherwise they'd have incentive to clear it up.
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Oct 9, 2019 21:23
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yep, sometimes even boring stuff like padding out run times by a minute or two so you finish your quota at a convenient time for catching the local (lovely, infrequent, suburb industrial park) mass transit home or weird poo poo you can't predict until you do sufficiently weird jobs. i worked on one v particular contract part run, described using the words "optical" and "surface finish" in the same sentence, where the limiting factor on cutting run times ended up being how fast the flood coolant could recycle back into the sump, because the huge mass of somewhat-absorbent fluffy acrylic shavings, created by running pallets of large board-like parts needing multiple fine facing operations, ended up soaking up and retaining a large fraction of the total coolant in circulation in the machine without ever clogging, and any significant interruptions or sputtering in the flood coolant would ruin the surface finish and also the part. so we just worked around it, because trying to fix or address it always added even more time per part and didn't work anyways
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Oct 9, 2019 21:34
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Karia posted:Got curious and looked it up. There was a lot of pushback on Reddit so she posted some followup. I'm omitting a lot of self-agrandizement, the person seems full of herself and really obnoxious, but does seem to know what they're doing RE: basic process optimization. If the person is good enough to make all these changes competently without risking a crash, I'd say go for it. But I also wouldn't blame a shop for not trusting some new hire to mess with processes that work well enough regardless of how much experience they have on paper. That's all pretty straight forward stuff, but they hosed up by A) lying on the timesheet and B) Running the code without permission. Just because they're 3rd or 4th hand machines doesn't mean they aren't gonna cost a shitload to fix or replace on short notice when someone swaps the tooling around and now that 0.050 clearance becomes a hard crash. Running the sim in fusion side by side showing the slowass way the code runs now, and the hot new sexiness her code does, the boss can more easily see the cost savings. Bossman likes it? Great! Bossman says to shut up and get back to work? Sucks to be you, I guess?
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Oct 9, 2019 23:06
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Methylethylaldehyde posted:Running the sim in fusion side by side showing the slowass way the code runs now, and the hot new sexiness her code does, the boss can more easily see the cost savings. Bossman likes it? Great! Bossman says to shut up and get back to work? Sucks to be you, I guess? Doing 4x the work in the same time = valuable employee Lying about hours and hiding the program = untrustworthy employee
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Oct 9, 2019 23:15
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Rapulum_Dei posted:Doing 4x the work in the same time = valuable employee In any place I've worked, that's a clearly fire-able offense. 1. They specifically asked about running their program, were told no. Running it is clear disobedience. 2. Lying on your time card is fraud. Sorry, you're canned and everyone the shop owner knows is getting called, AKA you're blacklisted.
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Oct 10, 2019 00:41
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We've had folks go it there own way, which is sometimes OK. But on critical stuff it just doesn't happen. Our lot sheet defines how it's done, inspection frequency, requirements, everything. You divert from what we planned for and now it's out of control. You might do it faster but all you've done is potentially made more out of control parts. That said we've absolutely had new hires come in and say "I think this is better", we evaluate it using the Continuous Improvement process and prove it out. Before I was born there was a big machine shop in town with something like 2400 employees. Each machine operator would "bid" on a job. A union rep would do a time study with a company rep. (My grandfather was the union time study rep) Each side would agree on a proper rate then the operator would bid on it. So you might bid low, but have a better method, and end up making more money for piece work. In the long run though everyone tried to gently caress on the time study so they could get paid for 40 hours of work for an 8 hour shift. In the end it was a lovely idea that led to cutting corners, bad parts, and a management method that seemed good on paper but in reality was a horror show. We watch rate pretty closely in our shop for variance up and down. If it's low it's not "why didn't you get rate?" but "Did you have a machine or part problem?". Usually people legit had a problem, tried to struggle through it, and had a bad shift. We do the same if someone goes way over rate, QA digs into the parts. We know pretty much exactly how fast you can remove material, so if you can go faster what aren't you doing that the other 40 operators are? It's always measuring less parts, not measuring surface finish, or damaging parts going in-out of the machine.
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Oct 10, 2019 00:57
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I'm not going to dig for the Reddit OP but yeah, that's typical engineering student thinking - herp derp I'm so smart I can go over people's heads. It's good that they're going into engineering because getting blacklisted as a CNC operator might not be the end of the world for them.
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Oct 10, 2019 01:11
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mekilljoydammit posted:I'm not going to dig for the Reddit OP but yeah, that's typical engineering student thinking - herp derp I'm so smart I can go over people's heads. yeah, the real issue here isnt whether he's right, it's him bigtime loving up the implied No. 1 job task of every paid position on the planet: fulfilling his role effectively and in concert with everybody else. running parts is just one part of that role, alongside even bigger ones like "do what we say". if your boss hires you to do X, directs you to do X, and then you do Y instead and then lie about it, that's gonna lose you your job p much anywhere, and still involves you being fundamentally bad at your job taken as a whole even if you're right everybody else who isn't this guy handles this situation without destroying their employer's trust by... just... doing X, like your boss told you, but also suggesting Y and maybe even pulling a little tech demo of Y together over your lunch break and showing it off alongside X. that one gets you more responsibilities and trust, instead of "none at all effective immediately" Ambrose Burnside fucked around with this message at 02:20 on Oct 10, 2019 |
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Oct 10, 2019 02:15
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Yeah, you know what's a better long term skill than some engineering trick you figured out? Dealing with people in a way that doesn't burn bridges.
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Oct 10, 2019 02:34
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I used to be an undergrad engineer and the company I worked for had 2 cnc machines, at the end of it I was responsible for programming and the dudes on the floor for running it. I rewrote our existing codes for composite sandwich panels, only changing the movements for travel between operations, bc the post processor was old garbage and did a terrible job of processing travel. We always programmed the ops in the most effective manner travel wide (i.e. for a mobile home side panel, doing the internal parts from left to right or in a clockwise motion, then doing the outside shape to finish). BUT the optimisation was a combined effort of mine and the workshop manager, so if they think they've got a better way to do it, talk to the program owner, show them how you'd do it to optimise it, but don't go over their head. I guarantee the program owner has done much more programming. Having said that, sometimes the program owner is a dumb bitch who won't see that you're trying to help, but it's not your place to go and do what that person did if you're not in the programming job and are hired as a grunt
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Oct 10, 2019 03:13
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quote:My rapids are setup for .05” instead of .5” of clearance which cuts down on the time spent cutting air. This is the fatal flaw, first time an insert breaks the machine's going to crash.
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Oct 10, 2019 03:53
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I have a question on bearings, one of the bearings from the gearbox that feels bad, is a NUP 206 bearing, roller bearing with a steel cage. The only bearing I can find at my local bearing supplier* is with a brass cage. Would this be OK to swap out? I'd like to order all bearings from one place for shipping reasons. * = of a trusted brand like SKF, FAG, Koyo, they do have ISB which I don't know is a reputable brand His Divine Shadow fucked around with this message at 07:03 on Oct 10, 2019 |
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Oct 10, 2019 06:47
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Are you looking at the FAG NUP206-E-XL-TVP2? The catalog load and RPM specs for that are significantly higher than a steel cage NSK NUP206-EW so you should be fine, my only concern would be lubricant compatibility. shame on an IGA fucked around with this message at 12:35 on Oct 10, 2019 |
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Oct 10, 2019 12:31
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shame on an IGA posted:Are you looking at the FAG NUP206-E-XL-TVP2?
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Oct 10, 2019 12:49
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shame on an IGA, unknown on the actual actual brand, they only say it will be an "FAG, Koyo Fersa or SKF", but they should be all pretty equivalent to each other. I am using Tellus S2 V 68 oil and I remember reading it was OK with "yellow metals". There are bronze bearings and components in the shaft already too.
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Oct 10, 2019 13:29
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Hello again, metal people. I tend to pop in asking for very specific advice since I'm not really a metalworker, so please forgive yet another odd one: I'd like to make something like this:  and I can turn the wood part on a lathe in minutes, but haven't found any brass hardware that would fit the bill. Nevermind getting a full cap and matching thread insert -- just the threads are impossible to find. Or maybe not impossible, but an annoying pain in the rear end -- I've had to use large BSP fittings which I'd cut and round in order to make them work. Not to mention that the fittings I found top out at 3/4" ID, and they're relatively expensive for what I'm trying to do. So I took a course in using the metal lathe at my local hackerspace, figured I'd learn to machine my own threaded inserts. I haven't tried it yet, and when I do it'll be manual, but where the hell do I find stock for this purpose that isn't hugely expensive/wasteful? My idea was to experiment with brass pipe of a large diameter (2-3") a wall thickness of about 1/8"-1/4" so that I don't have to first bore out and waste 95% of expensive stock. Problem is, I don't know where to find that, other than Alibaba where the brass is cheap but the shipping ain't. Does anyone know of US stores which sell hobbyist-level quantities, or am I stuck with scrounging local shops and trawling eBay? Or should I give up on brass altogether, switch to aluminum, and figure out how to anodize it instead?
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Oct 11, 2019 06:40
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Trabant posted:
I'd do proof of concept on aluminum (at elevated McMaster prices, 3" OD 6061, 1/4"" Wall, 12", $45) compared to ~$200 for brass of a similar dimension. You could look into brass railings, they might have something close to what you need without being ridiculous expensive. Aluminum, from an aluminum supplier, is ridiculously cheap. Same with anodizing. We ship all our poo poo out for anodizing and it's so cheap I wonder how they even make money doing it.
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Oct 11, 2019 13:24
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Yooper posted:. We ship all our poo poo out for anodizing and it's so cheap I wonder how they even make money doing it. Probably depends on penetration.
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Oct 11, 2019 23:03
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wesleywillis posted:Probably depends on penetration. Maximum penetration. We always go as deep, hard, and tough, as we can.
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Oct 12, 2019 00:28
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cross posting my knife post because I also made some Damascus and a pipe tamp   quote:
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Oct 13, 2019 18:42
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Update: x axis set to diameter Y axis to radius Changed x to radius as well and it’s reading 1:1 now. 
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Oct 13, 2019 21:25
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Yooper posted:I'd do proof of concept on aluminum (at elevated McMaster prices, 3" OD 6061, 1/4"" Wall, 12", $45) compared to ~$200 for brass of a similar dimension. You could look into brass railings, they might have something close to what you need without being ridiculous expensive. Aluminum, from an aluminum supplier, is ridiculously cheap. Same with anodizing. We ship all our poo poo out for anodizing and it's so cheap I wonder how they even make money doing it. That certainly seems to be the best way forward -- thanks for the confirmation.
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Oct 14, 2019 05:13
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you want to look up your local Metal(s) Supplier, Metal Distributor, Metal Supply Place, Metal Supply House, etc. they're all over the US/North America/Western Hemisphere etc because Our N e e d is voracious and all-encompassing. Use Google to find places, natch, but also make sure to check your local Yellow Pages for options b/c these places are all old-school. on that note, try calling before you email. their probably-limited web presence and/or phonebook listing/print ad should clearly indicate if they're ~open to the public~ and/or have minimum quantities, but you'll find out either way when you try placing a quote with someone over the phone, which is often the quickest + most common way these places accept orders from customers looking for same-day pickups. most product should be sold by weight, and they should be able to tell you the per-pound rate for a given alloy (try 6061) + stock profile, which you can specify all confident and proper-like by picking a suitable product from said distributor's product catalog in any case the metal for your project would probably be "like 5 bucks or less" if we're talkin boring ol aluminum, so it will be NBD to buy a single length of round bar or better yet thick-wall extruded seamless tubing/pipe that will cover a couple of these units, b/c 1) you will gently caress up, maybe a few times, w threadcutting often irreparably so, or 2) you will get an itch to create an improved or v2 component by the end, as you work the fiddly bits of this particular set of machining operations out for yourself and gain control over the results you're getting. also, critically, you need that spare bar for the chuck to grab on to while keeping all the machining clear of the spinning jaws you might find a well-suited stub of brass bar while you're rooting through your chosen retailer's cutoff bins; get a quote for such a chunk and see what the sticker shock is like. if you can deal with the brass price, imo it'd be a mistake to not prototype it in something cheap first, or at least use aluminum to practice the operations you'll need to do in brass if you're not comfortable with them. the most dramatic improvement you'll ever make as a metalcrafter is between your first project and your second, so it's well-worth it.
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Oct 14, 2019 06:16
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The A50 has arrived. I get to borrow a workshop crane from work this weekend, so I should have my mill in a better place soon. Nothing to it but the doing.
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Oct 15, 2019 20:59
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Leveled my lathe again after I had moved it a while ago. This is probably as good as it will get since the lathe is not bolted down and I was chasing my own tail there for a while.  Ideally I'd have a check bar to put in the spindle taper and be able to check how the spindle is oriented vertically too.
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Oct 19, 2019 10:28
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I got this idea for a burger smasher (also for press sandwiches). I wonder though if the wood might become too warm and start smoking, as I heat it up before using, gets the patty cooked fast and good. Ordered some PTFE round stock though, to make a small heat shield from.
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Oct 22, 2019 12:47
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That's a good looking meatmasher. I used one similar back when I worked in a restaurant in college. When we used them it'd just smash the burger on the grill and that was it, it didn't remain on the burger. Ours looked like square masons trowels though.
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Oct 22, 2019 13:18
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I got a square one like that too, but it's not optimal for use in a round pan, and I find it's easy to burn your hands if you don't grip the handle right in the middle. I also have ideas for making one with grill grooves, when I get the mill working. Anyway I got the idea of using them hot from watching local burger joints, the kinds that are operated out of a caravan or hole in the wall. I was also thinking maybe I'll make one to give away, kids preschool got some kinda auction coming up to raise money and wants the parents to donate homemade stuff. I was thinking a rolling pin or cutting board, but maybe a burger press could be something. Not sure I got a suitably large dimension of round stock at home or not though...
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Oct 22, 2019 13:26
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Bonus points if you cut it into the shape of a pig. 
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Oct 22, 2019 14:07
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It's lathe work so only round shapes. Started on it tonight: 
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Oct 22, 2019 17:50
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