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Kenshin posted:That makes complete sense. Yeah I've made like one knife, and lots of pieces of scrap that would have looked like knives if I was better. Thats kind of what happens in a general metalwork thread I guess.
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Jun 24, 2019 01:35
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Also, I want to build https://www.youtube.com/watch?v=e4qdhd10xtA but I have no idea where to get square steel tubing the Beaverton/Portland area. What should I look for as a business that would carry that kind of material Actually this one looks much better for my floor plan https://www.youtube.com/watch?v=KVxmxU3N3tI Anyone know the name of the mechanism (V shaped) at the timestamp here https://www.youtube.com/watch?v=KVxmxU3N3tI&t=53s I know it's purpose, and I know why it exists but I wouldn't know how to make one from scratch and it would be nice to know its name so I can look for plans for my own. LegoMan fucked around with this message at 03:16 on Jun 24, 2019 |
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Jun 24, 2019 02:58
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http://kck.st/2XjxSNS So someone is trying to make a desktop CNC, and solve rigidity issue by using epoxy granite rather than have it weigh a metric ton. The CNC and DIYCNC subreddits have both been pretty harsh on the project, but I don’t see anything else in the 4K price range with nearly the same capability. What does this group think about it?
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Jun 24, 2019 04:39
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I did some scraping this weekend, I don't have a surface plate, I don't have a holder for my carbide blade so I used a vice grip to hold it, and it was a precision part (tapered gib). Sounds set up for success right  Well I only had to remove material from a specific location on the gib. This is the same tapered gib that got under so much stress it sheared off the metal tab keeping it locked to the adjustment screw and also bent that screw so I almost didn't get it. Because it galled in place and I spent a week getting it loose, thinking I'd never succeed. Well the large amounts of forces on this steel gib (not a CI one) cause the narrow end to mushroom to the point it would not reseat properly. So I had to remove the material that protruded. I scraped it off and I improvised a reference surface using the box ways on the machine itself. blued it up with layout fluid and kept going till the gib produced a good enough contact pattern. By pressing the gib against the reference surface one can also get an idea of how much material we're talking about, it was only a few hundredths of a mm though, maybe a tenth of a mm at most. Also a demonstration of cosine error in the pic, .15mm feeler gage results in .22mm on the dial because of it. You can use this to magnify errors and make it easier to read, not good if you want absolute values, though with a feeler gage or otherwise known quantity, one gets the info required to make a conversion ratio, until you move the indicator again... 
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Jun 24, 2019 07:20
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Yearly reminder not to take any steel from railways as it is a federal felony and railroad cops are still a thing.
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Jun 24, 2019 11:15
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street doc posted:http://kck.st/2XjxSNS The frame isn't bad as far as it goes - provided they do everything right, 250lbs for a tiny mill is reasonable. The spindle is incredibly marginal for steel though, and I personally question the value proposition of a mill with an 8" cubed work area.
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Jun 24, 2019 19:20
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Pimblor posted:Yearly reminder not to take any steel from railways as it is a federal felony and railroad cops are still a thing. I read an anecdote of a guy who made the mistake of calling the railroad to try to get permission to scavenge before doing it anyway. A railroad cop was waiting for him. He was supposedly looking at 5 years.
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Jun 24, 2019 19:37
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street doc posted:http://kck.st/2XjxSNS The idea has potential, assuming their epoxy frame approach performs as claimed, but that doesn't matter to this particular design if the designers don't know what they want their mill to actually -do-. The components and design philosophies don't mesh in a complementary way. Like- there's always a place for small work envelope, precise cnc mills; this mill maps decently on to the Taig micro mill in a lot of ways, and I know of people who run those 8 hours a day every day making small, intricate 3d profile decorative pieces, jewellery/casting dies, stamps and the like. For that sort of work you need, among other things, good precision and repeatability and high sustainable spindle speeds and feed rates. This machine's got those in spades, apparently. But rigidity and vibration damping aren't nearly as critical. They matter, sure, but machine rigidity is almost never going to be the limiting factor while running the small end mills micro CNC mills are suited to, the tool gives up the ghost before the machine starts deflecting. The spindle, meanwhile, is small and quite fast, which is ideal for that small/precise work- and fantastically ill-suited to ever take advantage of the column's rigidity. It won't offer the low-end torque you'd need for larger tooling, which is where machine rigidity really starts mattering. And that feed rate- 130in/min is stellar for a small mill, taigs max out at 100 assuming ballscrews and closed-loop steppers, I make due with idk ~30ipm or so with boring ol leadscrews. Max feed rate is often the main determinant of program run time for little 3d profiling jobs... the type where machine rigidity isn't particularly critical. So- there could be a very nice little machine in here, but it'll be in spite of the whole epoxy column deal instead of because of it. I'm assuming the designer is knowingly shoehorning a poorly-applicable Also, they're probably taking advantage of people with lots of money and little experience who think there's One Weird Trick To Perfect Surface Finishes; it's a lot more complicated than Rigidity = Good Finish, but that isn't appealing to budding garage machinists in the way that something you can charge to your credit card and boom, beautiful parts, is. Ambrose Burnside fucked around with this message at 22:29 on Jun 24, 2019 |
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Jun 24, 2019 21:47
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Epoxy granite itself is a perfectly viable solution, proven by many others. But yeah, well put - it's really at a weird place.
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Jun 24, 2019 21:53
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What about putting on a larger spindle later on to actually benefit from the frame?
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Jun 24, 2019 22:06
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mekilljoydammit posted:Epoxy granite itself is a perfectly viable solution, proven by many others. But yeah, well put - it's really at a weird place. Yeah, 'gimmick' isn't a fair assessment of epoxy granite for this purpose. It's the only really notable thing about this particular commercial product, though, and is what all the promo copy is laser-fixated on as an elegant solution to a convoluted problem, so it's definitely wearing Gimmick's shoes,if not sharing its toothbrush, to invent an incredibly stupid and tortured analogy on the fly. street doc posted:What about putting on a larger spindle later on to actually benefit from the frame? Honestly, my suspicion is that the frame doesn't perform as well as they anticipate/claim, and they've compensated for this by downsizing the spindle to prevent people from colliding jarringly with its useful limit. It's a strange choice that I can't easily explain otherwise, aside from "the designers don't know very much about small cnc mills or hobby cnc machining", which is unlikely. If that's not the case, though, that's probably viable, yeah. If this ever took off I bet that'd be their first add-on or upgrade. e: also the Z axis only has 8" of travel, that may be a problem for much of the larger tooling that you'd want to be using with an extra-rigid mini mill. The taig's got 6" and it's a big limiting factor on the combinations of fixturing components and tooling you can use, good luck using anything with a non-superlow-profile vise, for instance. 2" more travel is a very significant improvement in that regard but it gets somewhat negated by the relatively-speaking bigger tooling they imply you can use; both mills use ER16 collets but with a taig you virtually never use the larger half of the shank range they can accomodate excepting tooling that's "shank-independent" like flycutters (where the shank is just a convenient size vs reflecting the working end like end mills and drills do). Full-size reamers and stuff would cause all sorts of problems if you can't cut the shanks down or feed the shank up into the spindle interior like you can with a Taig (which i'd assume you can also do here given the er collet system, to be fair) Ambrose Burnside fucked around with this message at 23:25 on Jun 24, 2019 |
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Jun 24, 2019 22:33
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TerminalSaint posted:I read an anecdote of a guy who made the mistake of calling the railroad to try to get permission to scavenge before doing it anyway. A railroad cop was waiting for him. He was supposedly looking at 5 years. Even "abandoned" rail lines are still owned by the railroads, the long arm of the law takes a dim view of people taking spikes as some methheads/scrappers/blacksmiths were actively pulling them out of the tracks.
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Jun 24, 2019 23:21
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I mean, looking at that, it's conforming to the Standard Chinese Brushless Spindle standard, and there's options for lower RPM versions that might work OK for steel/iron. I should comment that I've been looking at kitbashing together something towards the "you can do ferrous if you aren't in a hurry" end of things and doing a bunch of research to that end - so I just doubly don't get some of their decisions.
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Jun 25, 2019 00:08
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mekilljoydammit posted:I mean, looking at that, it's conforming to the Standard Chinese Brushless Spindle standard, and there's options for lower RPM versions that might work OK for steel/iron. Revealing my ignorance here, but I thought the issue with steel is that, even done slowly, any flexibility or chatter in your CNC would still affect the part. Which is why we all need 4 ton CNCs and a dedicated workshop building.
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Jun 25, 2019 02:26
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street doc posted:Revealing my ignorance here, but I thought the issue with steel is that, even done slowly, any flexibility or chatter in your CNC would still affect the part. Which is why we all need 4 ton CNCs and a dedicated workshop building. It's not like there's anything magical about steel that makes it particularly harder on your machine. It just has significantly higher cutting forces than, say, aluminum, so your cuts are more likely to excite chatter or deflect your tool/workpiece/machine. Use small tools, low depths of cut, stepovers, and chiploads, and you can do a lot even with a very small machine. It'll just take a long time. Compensate as best you can with high spindle speeds.
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Jun 25, 2019 03:04
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street doc posted:Revealing my ignorance here, but I thought the issue with steel is that, even done slowly, any flexibility or chatter in your CNC would still affect the part. Which is why we all need 4 ton CNCs and a dedicated workshop building. Everything's flexible; 4 or 40 ton CNCs aren't perfectly rigid either. Wood puts forces on the cutting tool, brass puts forces on it, aluminum does, and so does steel, all of it will lead to deflection to some degree, and enough for any of it will hurt finish/etc. Think of all of it in terms of X amount of energy to remove Y amount of volume; harder/denser stuff takes more. So, basically, the rate you can dump energy in is spindle horsepower and how well it resists that is tied to deflection. Lighter machines you have to reduce forces - which means reduce the volume rate of stuff you're cutting. But when you reduce feed rate, you need to reduce tool speed too - long story short, spinning the cutting tool really fast and feeding slow smears things instead of cutting them. This ties into the problem with the high speed brushless spindles - they're not geared. So you have 1.5kW at 24,000 RPM but for a reasonably sized (for that size of frame) cutting tool in iron or steel you may want more like 2,000 RPM... and these ungeared brushless spindles have more or less no power that slow.
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Jun 25, 2019 03:12
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Today like a god damned idiot I dried my hands off using a rag that I forgot I had last used to sweep up a bunch of tiny metal shavings. Now I have at least 12 tiny metal slivers in my fingers, the kind that are too small to pull out and you don't even notice them until you grab something in just the right way and it jams in deeper and aaaaaaagh.
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Jun 27, 2019 02:14
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I do that sometimes wiping my hand on my pant leg. It's the worst. Fingernail clippers work the best imo. And never get an MRI lol.
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Jun 27, 2019 02:49
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Sagebrush posted:Today like a god damned idiot I dried my hands off using a rag that I forgot I had last used to sweep up a bunch of tiny metal shavings. Now I have at least 12 tiny metal slivers in my fingers, the kind that are too small to pull out and you don't even notice them until you grab something in just the right way and it jams in deeper and aaaaaaagh. I had a few such bastards, a small neodynium magnet helped raise them up so I could pull them out with tweezers. A loupe also helps. I wonder if a really strong one might just get them out on it's own
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Jun 27, 2019 04:33
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Speaking of splinters, who makes the best tweezers? I want razor sharp, ridgid, and durable. Price is no object within reason.
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Jun 27, 2019 05:04
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Not tweezers but these have worked pretty good for wood splinters.
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Jun 27, 2019 05:50
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honda whisperer posted:Speaking of splinters, who makes the best tweezers? I want razor sharp, ridgid, and durable. Price is no object within reason. Swiss army knife tweezers are the poo poo. Make sure its a real one. The fake ones don't work good.
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Jun 27, 2019 11:26
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honda whisperer posted:Speaking of splinters, who makes the best tweezers? I want razor sharp, ridgid, and durable. Price is no object within reason. Aven Technik
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Jun 27, 2019 14:03
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street doc posted:http://kck.st/2XjxSNS I don't trust someone trying to sell precision instruments that don't have a base wider than its middle.
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Jun 27, 2019 23:38
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What I've found more useful than really good tweezers when the chips are down is a jeweller's loupe and a very fine steel pin, with a flat stoned into the side about halfway through if I can swing it; that puts an edge onto the side of the pin so you can slice a bit, and also doubles as a 'paddle' surface. Stoning both sides of the pin head to produce an incredibly fine blade also works but who's got time for that, one facet is 95% as good. Use a bit of alcohol to sterilize pin and splinter site; get comfortable with loupe; pierce skin behind splinter w pin, paddle side up, using a slight side-to-side motion to enter with as little force or tearing as possible. Enter diagonally, locating paddle under the tip of the splinter. If it's a very deep splinter and you don't wanna dive under, try to stick it from the side with the pin tip, being careful not to shear it in half (a splinter butt left at maximum depth with nothing to grab is bad news bears) . Use pin to lift splinter up enough to get a firm grip with tweezers. Clean wound, bandage, enjoy your day. (don't get me wrong, i still advocate for top-quality tweezers, but the really pain-in-the-rear end splinters with bad Splinter Parameters often need more than tweezers, no matter how well-made) Ambrose Burnside fucked around with this message at 23:58 on Jun 27, 2019 |
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Jun 27, 2019 23:53
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Ambrose Burnside posted:What I've found more useful than really good tweezers is a jeweller's loupe and a very fine steel pin, with a flat stoned into the side about halfway through if I can swing it; that puts an edge onto the side of the pin so you can slice a bit, and also doubles as a 'paddle' surface. Diabetic testing lancets are exactly this but sterile, have a handle, and are like $4 for a box of 100
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Jun 27, 2019 23:57
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shame on an IGA posted:Diabetic testing lancets are exactly this but sterile, have a handle, and are like $4 for a box of 100 Why did I never think of this!
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Jun 28, 2019 00:00
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shame on an IGA posted:Diabetic testing lancets are exactly this but sterile, have a handle, and are like $4 for a box of 100 well yeah, sure, if you're the kind of weirdo who prioritizes "saving time" over "pathologically overengineering solutions to mundane problems for its own sake"
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Jun 28, 2019 00:02
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none of those people would be in this thread
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Jun 28, 2019 00:08
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I've always just found using nail clippers to cut the things out to be easiest.
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Jun 28, 2019 00:22
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Scotch Brite folks. Run it lightly over the area you have metal slivers, they get caught in it and pull right out.
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Jun 28, 2019 00:33
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The Swiss make very good, fine, sharp tweezers that are needlelike enought stick down parallel to the splinter and then they grip tight to pull it out. Grobet maybe? I used to have some with a maker's stamp that was like a jesus fish but I can't recall who made them.
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Jun 28, 2019 00:40
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shame on an IGA posted:Aven Technik Holy poo poo they're affordable too! 6 pack on the way. Thanks. Someone could probably make bank if they loaded a truck full of those and drove around to machine shops like the snap on of splinters. Diabetic test strips is also brilliant. Only thing like that I've done so far is modifying an air nozzle to take basketball inflation needles. Best thing ever for getting chips out of small holes. Break one? I've got 50 more.
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Jun 28, 2019 00:46
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Ambrose Burnside posted:well yeah, sure, if you're the kind of weirdo who prioritizes "saving time" over "pathologically overengineering solutions to mundane problems for its own sake" I feel like this should be the thread title in some way
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Jun 28, 2019 01:09
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with the assistance of friends i've branded myself with a couple designs (microbranding i.e. drawing designs with many small dotted brands that scar together into linework, not the usual strike branding with the one big single design), and i make myself my own point branding tools as needed; i've probably experimented with about 10 different variations in geometry and wire gauge. heres the only one i can see lying around- about 2" long, 1.6mm CP2 titanium wire, the coil section acts as a radiator to stop heat from bleeding up into the shepherd crook handle over dozens of brand reheats. practically speaking i like an L-shaped tool with a 90-deg bend near the working end
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Jun 28, 2019 01:17
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So funny musing today. Is there any good way to figure out what things would, approximately, cost to make? I have a bunch of pretty hashed out designs for various car parts but most of them would take better equipment than I have to do safely. I don't really want to be a machine shop in the "selling services to keep the lights on" sense, I'm looking more in terms of retrofitting some machines at a price level where I can treat it all as a hobby, then sell parts as extras. But I'm basically just completely mystified as to where the break-even point is or if the very concept is dumb.
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Jun 28, 2019 15:24
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Depends on if you're including the initial startup costs or not. If it's just per part then it's material, tool wear, and time. Time is the big one. If you're factoring in the startup then it depends on what the part needs. That new boring head needs a lot of parts to break even. Where I work the hourly rate includes tooling, electric, machine payments, consumable chemicals (coolant, cutting fluid etc) payroll, a/c etc. Estimated time to machine x hourly rate = acceptable profit if we actually make good parts in said time. Shops been in business for over 30 years so it's been refined pretty well. Can you share am example part? I'd start with said part needing this size chunk of material. These specific tools. This much time to make. $50 material, $300 tooling, 2hrs to machine @ $20 per hour (made up numbers) = $390 for part one. $90 for part 2 through tooling wears out. Say you make 10 parts you're into it for $1000.
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Jun 29, 2019 05:52
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If you want a hobby that pays for itself + walkaround money and don't consider buying the mill a business investment, imo it's fine to be a bit fast and loose at first as long as you don't commit to anything too big too fast or that you're not confident you can actually execute successfully. There's the standard factors- material costs, incidental expenses, a little more to offset the slow creep of wear on tooling/machinery, and of course paying off any tooling you're in hock for. Add on what your labor is worth to you, then make it 125% to factor for taxes (even if you're not big-time it's a good habit). Sum these as appropriate into a minimum job cost below which it isnt' worth your time, and a per-hour rate that factors for everything except material cost. Price jobs based on how long you think they'll take plus idk 125% material cost for non-precious metals. Always take am up-front deposit, 50% is a common basline, if they're not a good enough friend that you wouldn't gladly lend them money for the full commission value. Finally- You always undersell yourself at first, it's human psychology for almost everyone, so factor for that. For your first commissions, right before you quote someone, realize that you've probably negotiated yourself down from a gut-feel number before you've even opened your mouth. Fight that impulse and go with the first gut number that more or less reflects the trunkated criteria above , you can always negotiate. but don't trust that first-offer mental lowball, it's often chosen, imo, to make the client happy and "seal the sale" as much as it is to "give them a deal". As a craftsperson you make people happy by creating good products that customers learn to rely on and appreciate, not by trying to undercut Ikea or whatever other dumb poo poo people trip into early on. tl;dr- factor fixed material/equipment expenses and flexible hourly rates reflecting your actual worth into a single rate; don't lowbal yourself right out the gate if you like making poo poo money and havingpeope think you make "cheap stuff" and oh yeah, if it gets past sales to friends, draw up a contract. Furniture commissions are often 3-4 figures and poo poo can get nasty if it's all word-of-mouth until you need to get paid Ambrose Burnside fucked around with this message at 14:05 on Jun 30, 2019 |
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Jun 29, 2019 06:14
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This morning I started the removal of the headstock: Following the manual, all the stop dogs and indicators were removed earlier so removing the cover strip on the front. Part of the bellows were removed earlier as well.  Next I loosened the screws and removed assembly 4 in the manual, the blindd tapered pins are stuck real well, I thought helped to have the screws loosened, did not want to budge otherwise. Slide hammer is required. Good thing they are M6 at least.   Then I can remove the screw assembly by backing it out and supporting it with one hand  Next I remove the tapered gib  A quick cleanup shows the gib to look mostly fine, there wear is highly localized to a few spots near the narrower end.   After that I can lift up on the headstock and slide it off.  But I stopped here because the headstock feels too heavy to support by hand, I am wondering how I best go about it. Support it from the crane maybe, through the hole left when removing the horizontal spindle perhaps. I assume the Deckel people assumed you'd have two workers to lift it off.
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Jun 29, 2019 08:41
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Thanks guys. I'm sort of sitting at trying to sanity check myself - I'm eyeing machinery auctions and resellers and realizing that, well, with a bit of effort I do have a place to put stuff. I think I'm going to limit myself to a better lathe at this point - I don't have to build a building for that and what I'm looking at I wouldn't need to do financing. My aim is more manufacturing my own designs - but a halfway decent lathe plus the Bridgeport I have let's me do almost all the machining operations in house, albeit maybe not the fastest. If any money consistently comes out of that I'll think about expanding again but I think I'm fooling myself if I try to call even a used VMC a hobby machine.
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Jun 29, 2019 15:25
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