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CarForumPoster posted:1.5002 +.0002/-.0000 No quote!
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Aug 12, 2018 17:55
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What in the name of all that's loving holy are you doing that for?
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Aug 12, 2018 20:37
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CarForumPoster posted:1.5002 +.0002/-.0000 
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Aug 13, 2018 00:12
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So is that for like some kind of rocket engine injection nozzle or chemical reactor or something? Or is it just that those plans were drawn up by a junior engineer and he gonna get an rear end-kicking when his boss gets the bill?
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Aug 13, 2018 06:50
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Blacksmithing / Metalwork: Anything involving penetration has to be 1.5002 +.0002/-.0000
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Aug 13, 2018 08:26
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CarForumPoster posted:1.5002 +.0002/-.0000 
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Aug 13, 2018 11:06
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Disgruntled Bovine posted:We have a job at the moment which requires drilling a pattern of 105x .007 +/- .0002" holes in Monel. CarForumPoster posted:1.5002 +.0002/-.0000 lmao
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Aug 13, 2018 13:45
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in other news i'm starting on a laser engraver at work (150W so no metal cutting but it zips through most everything else) and they really shouldnt have certified my dumb rear end on it
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Aug 13, 2018 13:49
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Ambrose Burnside posted:in other news i'm starting on a laser engraver at work (150W so no metal cutting but it zips through most everything else) and they really shouldnt have certified my dumb rear end on it What type of laser? Our engraver is only 35w and it engraves metal, but can't do wood or plastic.
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Aug 13, 2018 19:11
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150W should be enough to cut thin sheet steel, like under 1mm or so, but metal cutting lasers work like a cutting torch, so you need an oxygen or nitrous oxide blast.
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Aug 13, 2018 19:17
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A Proper Uppercut posted:What type of laser? Our engraver is only 35w and it engraves metal, but can't do wood or plastic. A couple different models of CO2 Epilog machines. I know we can engrave anodized/painted/coated metals fine, or metals treated with that laser engraving compound, we just never bother because there's no call for it/conventional mill engraving is a better fit for the task. And yeha no oxygen blast, just compressed air, so metal cutting's never been seriously considered. But we have oxygen lines running to that shop that are unused as it stands, these machines have never gotten much attention beyond what was needed to get them running "enough" so who knows. I'm taking some initiative and trying to tap the unused potential here for purely selfish reasons- Epilog's software seems p robust and you can raster-engrave stuff in 'stamp' mode where it fakes up an approximation of 2.5D profile machining by putting ramps/chamfers between depth levels to produce usable stamps and nobody's ever even experimented with it. i wanna use it to try making extremely fast/easy matrix dies for hydraulic sheet metal forming, acrylic is sturdy enough for hydraulic die use and it'd let me turn a 10+ hour 3d profiling job with teeny tiny little endmills into 15 minutes of Lasers so loving around with designs would become trivial + i'd have few restrictions on design geometry Ambrose Burnside fucked around with this message at 20:01 on Aug 13, 2018 |
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Aug 13, 2018 19:55
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Sheet metal nerds : I'm working on a project that has some really small radii bent into the end of a sheet of 18 gage steel. We'll tig it all together but I'm getting some serious gently caress off looks from the sheet metal folks in my area. Is this do-able?  Any recommendations to make it easier on the brake monkeys who think 1/16 is a "pretty tight tolerance bruh"?
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Aug 14, 2018 00:19
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how do you expect to maintain that gap
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Aug 14, 2018 00:22
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shame on an IGA posted:how do you expect to maintain that gap We've got pins tig'd through just before the gap that will restrain it during weld. edit : Top piece and bottom are two distinct plates, not a single assembly prior to weld. Yooper fucked around with this message at 00:42 on Aug 14, 2018 |
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Aug 14, 2018 00:39
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Hello I'm a sheet metal monkey born and raised. What you are asking for involves a custom press brake die, in my opinion. Sheet Metal equipment is really not designed for bends or rolling without material in excess past the bend line. I hope you have a digital back gauge for your brakes, and a fellow or two more interested in using a caliper than a tape measure. [Edit] Upon further examination in my shop I'd do this with a) a custom coining press die for the small radius and b) a custom air bending die for the large radius. And a good talking to the brake operator to lock in his blank to position, back off the back gauge, and then hit. I just hope the bend isn't too long. Mr. Bill fucked around with this message at 00:52 on Aug 14, 2018 |
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Aug 14, 2018 00:49
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Bend wouldn't exceed 12". Adding material beyond the bend isn't a problem, we can remove it prior to assembly. We might machine those radii and tig them on too, still determining the best method.
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Aug 14, 2018 00:57
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Well if you're adding material, you can probably get away with varying sizes of bottom v dies to bend to needed radii; as long as you're okay with surface finish having knife-style scratches, and endmill off the excess (I'd recommend at least 1/4" excess). You won't be able to shear off excess easily, though, as you're kind of hilariously close to the tangent line.
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Aug 14, 2018 01:09
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Cool, thanks dude. I'll give this a go. Once I get it together I'll snap a few pics.
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Aug 14, 2018 01:31
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Sagebrush posted:So is that for like some kind of rocket engine injection nozzle or chemical reactor or something? Or is it just that those plans were drawn up by a junior engineer and he gonna get an rear end-kicking when his boss gets the bill? MohawkSatan posted:What in the name of all that's loving holy are you doing that for? I wasn't the person with that job.  This guy gets it
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Aug 14, 2018 22:12
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I've started loving around with hydraulic die-forming and man oh man there's so much potential here aaaaaa  here's the basic setup. die-formed blank on left, setup with a different die on right. I'm using the laser cutter to knock silhouette dies out really fast- so far just some experimental geometric forms- and then put a sheet metal blank between the die and a hard urethane pad.I sandwich all that between two heavy steel plates to distribute the ram force more equitably and then pump the powerpack.  closeup of a formed part. this one bottomed out in the die so it has a flat face + texture from the rough steel plate but given sufficient depth the surface will be totally organic curves with depth corresponding to the distance from the die edge. Also note how the edges of the blank get sucked in towards the impression- it moves metal more than it stretches it locally, so you can draw deeper forms with hydraulic forming than with traditional sinking techniques.  Cutting the blanks free from the sheet. It's possible to make simple blanking dies appropriate to the hydraulic press but i'm not there yet so tin snips and a jeweller's saw it is.  The finished formed pieces. This could be a necklace, use jumprings or fine chain to suspend each as a pendant charm, but mostly I was just loving around and didn't think far ahead beyond "oh man this is cool" hydraulic dieforming is a really powerful technique to bridge mass-production conforming die sheet metal manufacture and one-off artisanal production, but having a means to quickly and effortlessly produce tooling elevates it massively. it took, no poo poo, less than 10 minutes to produce what is functionally production tooling for a simple multi-component jewellery design and then produce a sample with that tooling. i'm already giddy thinking about the places i can take this along the lines of elaborate single-sheet repousse designs...
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Aug 19, 2018 23:05
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drat, that's loving awesome.
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Aug 20, 2018 01:05
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I'm in the process of spec'ing out and ordering half a dozen OD grinders. We haven't had to buy equipment like this in quite a few years so I start out searching for basis price. Mainly defining the outline of the budget. German machine : $1050k Swiss machine : $800k High End Japanese : $350k English : $300k Italian : $300k Indian : $200k And then things start to get funky. Taiwanese : $100k-$150k Chinese : $60k-$105k As far as I can tell the castings / rough work is actually done in China and then exported to Taiwan where the machine is "finished". We have one Taiwanese grinder and it's kind of a turd factory. On that one we absolutely know the machine was made by someone else in China and marketed as a different brand in Taiwan. With the 25% machine tool tariffs and such I expect to see much more of this from Taiwan. The Chinese machine is priced as a mystery because no one has ever seen one. I expect the maintenance and support to be as non-existent. We only had one quote from one US manufacturer so far but it's not apples to apples as they only offer a 14" grinding wheel whereas the others are all larger wheels. The US machine was competitive at $135k. I'm still waiting on a few quotes from more US folks. So uh, if anyone knows a good angular approach OD grinder...
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Aug 20, 2018 13:24
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Ambrose Burnside posted:here's the basic setup. die-formed blank on left, setup with a different die on right. I'm using the laser cutter to knock silhouette dies out really fast- so far just some experimental geometric forms- and then put a sheet metal blank between the die and a hard urethane pad.I sandwich all that between two heavy steel plates to distribute the ram force more equitably and then pump the powerpack. This is really cool - assuming that die's something like lexan or whatever, how does that hold up moving sheetmetal around?
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Aug 20, 2018 14:18
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I've got some guttering that needs some adjustment, currently rough-cut unfinished lead. I can make small adjustments just by bending etc but my understanding is that the best way to work with it is torch welding? I'm hesitant to do that because all forms of welding take more practice and skill than I have time or work for, and £100 for even a cheap kit is a lot for the handful of jobs I have to do. So far I've been working with flashing tape (tar-backed aluminium) which I can work with a regular heat gun, but it doesn't seem like as professional a job. That said, I do have a bunch of spare lead available.
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Aug 20, 2018 15:25
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I drive an old-ish (2003) BMW f650cs motorcycle, in a really goofy looking blue color. Like any rational human being, I decided it would look better in black, so I got some black fairings for it. All of them are trivially easy to swap except the front fender. There are (were) 4 stainless steel bolts holding the fender on, screwed into protrusions on the aluminum front forks. Galvanic corrosion is killing me. You can see the mounting points pretty well in this photo  . There are two per side, sticking up from it in the lower right side of the image. My fork is still on the bike though, and there's a wheel and whatnot in there as well.Even with liberal applications of penetrating oil, and trying to loosen the bolts a bit at a time over the course of a week, I ended up shearing the heads off 3 of the 4, and the 4th has me frustrated enough that I am just going to cut it off I think. I've resigned myself to drilling them out and tapping them, but I was wondering if anyone had any suggestions on a DIY drill guide since I'll have to hand drill them.
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Aug 20, 2018 15:36
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Ambrose Burnside posted:I've started loving around with hydraulic die-forming and man oh man there's so much potential here aaaaaa Is that the Cone-head symbol?
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Aug 20, 2018 20:27
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Yooper posted:German machine : $1050k That seems like a massive price drop from the German and Swiss machines to everyone else. Are they so _much_ more amazing to demand a high premium like that?
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Aug 21, 2018 00:09
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We had an okuma at my last job. I didn't run it much but that machine was never down. Ran +/-.0002 all the time. The programming is super straightforward. I can't imagine high end grinders offer much over their competition.
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Aug 21, 2018 00:29
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I would agree, the Japanese really know how to build a machine tool. Also a measuring tool.
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Aug 21, 2018 00:45
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I work for a German company, they're not shy about paying the 300% nationalism tax. Even then, there just isn't a machine that can economically hold the tolerances that go into bearing needles or they'd be using it. High volume super precision stuff like that it's send them through a centerless grinder, sample to see how much tumble polishing they need to wind up in the distribution range, and then 100% sort them into .002 mm bins.
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Aug 21, 2018 01:17
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I'm a woodworker but want to know more about machining. Can someone explain to me how precision grinders stay accurate? How do they know how much of the wheel has worn away or does it measure the part itself as it is grinding? Or do they use some super hard abrasives that don't wear down like a normal grinding wheel?
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Aug 21, 2018 01:56
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MrPete posted:That seems like a massive price drop from the German and Swiss machines to everyone else. Are they so _much_ more amazing to demand a high premium like that? I'm not entirely sure. My guess is you use it for a high volume-high complexity-high throughput cell where you can squeeze every single penny out of a contract. Both the German and Swiss came at it from a profitability standpoint rather than capability. They knew the machine was capable, all that needed to be determined was how profitable it would be. For our particular op the tolerance isn't the big issue, other than runout it's fairly normal. Our main concern are reliability, service-parts availability, and to not own a great white elephant special snowflake machine. My biggest issue is getting a machine I can mount a full diameter wheel on the right that can also swivel to 45 degrees and a company open-minded enough to mount the workhead where the tailstock normally goes. Angular approach normally fits the bill but Shigiya makes a machine that might fit the bill...
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Aug 21, 2018 01:58
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Kaiser Schnitzel posted:I'm a woodworker but want to know more about machining. Can someone explain to me how precision grinders stay accurate? How do they know how much of the wheel has worn away or does it measure the part itself as it is grinding? Or do they use some super hard abrasives that don't wear down like a normal grinding wheel? Pretty much the second thing. You will grind to within less than a thousandth or so depending on material, then redress the wheel and re-zero the wheel on the top of the material and bring it down to size. There are probably grinders that will automatically compensate for wheel wear but I just have experience with manual surface grinders.
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Aug 21, 2018 02:09
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Kaiser Schnitzel posted:I'm a woodworker but want to know more about machining. Can someone explain to me how precision grinders stay accurate? How do they know how much of the wheel has worn away or does it measure the part itself as it is grinding? Or do they use some super hard abrasives that don't wear down like a normal grinding wheel? They go through a process called dressing every few cycles. It regrinds the wheel and compensates for how much of the wheel was taken off so that it consistently gives you the same results. Plus you can always just rerun the part after you make an adjustment if the wheel shrinks enough to make the part oversize.
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Aug 21, 2018 02:10
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Grinding's not my specialty, but we've got a couple of Okamoto surface grinders our spindle repair guys use, they might be worth looking in to if they've got a machine that fits your needs, I've heard very good things.
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Aug 21, 2018 02:20
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Kaiser Schnitzel posted:I'm a woodworker but want to know more about machining. Can someone explain to me how precision grinders stay accurate? How do they know how much of the wheel has worn away or does it measure the part itself as it is grinding? Or do they use some super hard abrasives that don't wear down like a normal grinding wheel? This Old Tony covers it pretty well https://youtu.be/npybvhWYklc Essentially the wheel is a little bit softer than normal abrasive, but by stoning it with a diamond that has a known height above your magchuck you know where the wheel starts in the Z axis.
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Aug 21, 2018 02:26
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mekilljoydammit posted:This is really cool - assuming that die's something like lexan or whatever, how does that hold up moving sheetmetal around? I'm using acrylic because it's amenable to being laser-cut, and you hit its limits fairly easily- i tried to do a shallow emboss of lettering with thick ~22ga. nickel silver and got it up to 25 tons without getting more than a ghost of an emboss, but the die has stress fractures radiating out from the hard corners of the letters. That was basically trying to extrude thick sheet metal into narrow channels, though, which is just not a good way to go about this. For details like that you do it the opposite, you make a positive die and press it into the metal-urethane sandwich like a ram. I'm gonna tackle that with some CP2 titanium sheet tomorrow maybe?? i have access to a waterjet cutter so if I really want a die with details that acrylic can't support under significant tonnage i can just waterjet it from steel, but that's a bigger hassle than the laser so I haven't bothered yet
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Aug 21, 2018 03:09
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I ran into a local job shop owner at the bar and passed your angle entry grinder question along, without hesitation or seeing the list he said Okuma.
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Aug 21, 2018 04:24
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MrPete posted:That seems like a massive price drop from the German and Swiss machines to everyone else. Are they so _much_ more amazing to demand a high premium like that? The german ones make good product, but have issues with the cooling systems. The Swiss ones are as good as the German ones but also keep excellent time.
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Aug 21, 2018 07:35
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shame on an IGA posted:I ran into a local job shop owner at the bar and passed your angle entry grinder question along, without hesitation or seeing the list he said Okuma. Thanks! We reached out to them a few years ago but they didn't offer an angular approach at the time. Looking at the site they do now, so I'll hit em up.
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Aug 21, 2018 12:06
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