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I have been lurking in this thread for like 5 years now. I finally got the chance to do some work! My friend has a backyard forge and recently got some old wrought iron from a shipping barge wreck. I made a simple thing but im proud of it. I start real blacksmith classes at the end of the month. I got it a little to hot and burnt the hell out of one of my scrolls. i didn't get a before pic but it started out as a rusty lump of iron.   
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Sep 5, 2017 23:10
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I appear to have undertaken a bit of a project without really researching whether it was possible or feasible, and I could do with some advice... It's my bronze wedding anniversary this year (actually it was last year, but we got two years mixed up and did pottery last year, which was a walk in the park compared to this) and I decided to make a bronze "card" with an etching of a pattern inspired by my wife's wedding dress. I've got the design on paper, a 1.2mm sheet of 200mm x 100mm PB102 bronze, a load of ferric chloride to etch it and gloves and eye protection. That's about it. What I don't have are any specialised tools of any kind beyond a minimal home toolkit, or any ability. What I want to end up with is something that looks like a greetings card, with the pattern etched on the front and some writing etched on the inside, bent at about a 60 degree angle. As I understand it, I will probably need a sheet metal bender to do the bending (which I may have access to through a friend). Does anyone have any advice about annealing (whether it's required, how to do it, what to do afterwards to harden the metal again), and the etching (concentrations, times, whether to do it before or after the etching)? I really didn't think this through beforehand, but I think it's a cool idea and I'd really like to do a good job... So I'd also appreciate any general hints and tips for amateur bronze working and etching. Scientastic fucked around with this message at 16:01 on Sep 8, 2017 |
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Sep 8, 2017 15:59
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Submersion etching is pretty straight forward. Cover the parts you don't want etched in a resist, and then toss it in the ferric chloride. Apparently hydrogen peroxide makes the ferric work even better. Also, swirl the solution around to help remove the particles from the area being etched. As for timing, just put it in for a few minutes and then pull it out and check the progress and repeat. I do both submersion and electro-etching. I would anneal first, as the colour will change when done. Then clean it all up and etch it, since the etch needs a roughed up surface to work, and you'll need to remove the fire scale from the copper. If you just need to bend it to 60° and nothing else, I wouldn't even bother annealing though. Because you are using copper or bronze, the sheet will probably come half hard anyways, and it won't be flopping around or anything, even when annealed. For annealing, watch the colour for a full cherry glow in a dim room, or watch for the colour to go shiny silver/grey. You can do the bend on a sharp corner of a table even. Just make sure to line it up well and maybe use mallet to do the final shape on the fold. Brekelefuw fucked around with this message at 16:12 on Sep 8, 2017 |
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Sep 8, 2017 16:05
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And would you put the bend in first? My feeing is that etching will be easier if the bronze is a flat sheet, but that the bend might distort the pattern if I etch first...
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Sep 8, 2017 16:10
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I can't see it distorting the pattern. With the bend in the metal before, you will be able to hang just the part in need of etching in to the bucket, so it will reduce the amount of resist needed on the workpiece.
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Sep 8, 2017 16:13
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Here is one of my etched projects for a customer's trombone. Both sides were submersion electro-etched with salt water. I don't like working with ferric. 
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Sep 8, 2017 16:15
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drat dude, that's gorgeous.
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Sep 8, 2017 17:27
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Whoa, I just found another skillset I need to acquire if it can produce results like that. Unrelated, I started doing some thinking and I'm starting to look at CNC lathe conversions (I'm realistically too poor to buy one all at once) - my ideal is a horsepower or two in something like 14" swing and 40" travel. I've come across mention of people screwing up change gears / gearboxes by crashing lathes, and am wondering if looking for that is a viable way to find a starting point, and where (other than CL and stuff) I would look for semi-broken lathes. Or if this is an entirely stupid idea - I'm not looking at huge production rates, just something that once the code is proven, won't screw up the part because of operator error. *edit* Holy cow nevermind all of that - I just looked at the cost of used "broken" CNC stuff on ebay/etc. Even if I assume every part of the controller on a "broken" CNC machine is garbage, I'd still get all of the iron/motors/etc for far less than the cost of a manual lathe where I'd need to buy all the motors/ballscrews/encoders plus the controller... and in many cases for far beefier of machines. Now I just need to get a shop with 3-phase. mekilljoydammit fucked around with this message at 21:00 on Sep 8, 2017 |
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Sep 8, 2017 17:39
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Slung Blade posted:drat dude, that's gorgeous. The most difficult part was actually machining the brass part, as it had to be made to fit the original silver posts on the trombone brace it attached to, and also be light enough to not throw the balance of the horn off. It was about 2" diameter. Got to use my 4th axis rotary though. Hurray. 
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Sep 8, 2017 18:26
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Are there any good benchtop CNC milling options these days under $5000 that aren't more of a project in and of themselves than a machine tool? Would love to be able to fabricate small parts at home, but may just be a pipe dream.
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Sep 14, 2017 01:21
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I'm definitely not using mine to its full potential yet, but I'm generally pretty happy with my CNCed Taig micro mill setup from Soigeneris. I was in your boat too- wanted to make parts with an absolute minimum of futzing with the machine build itself- and Jeff Birt's kit came very highly recommended. It's about as close to a turnkey Taig setup as you can get, he hooks you up with all the software/config files/general setup crap you need, and he personally offers great support and troubleshooting once you're setting it up. That said, the Taig has a drat small work envelope, so it'll really depend on the materials and part dimensions you're thinking of.
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Sep 14, 2017 02:22
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Ambrose Burnside posted:I've got a soft spot for that kind of very physical analog "programming", it can get really neat. I can't post a vid right now but check out rose engines and how they use spindle-mounted shaped wheels to do really intricate geometric turning/engraving work, it's fascinating.  https://youtu.be/s1i-dnAH9Y4
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Sep 14, 2017 02:51
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Ambrose Burnside posted:I'm definitely not using mine to its full potential yet, but I'm generally pretty happy with my CNCed Taig micro mill setup from Soigeneris. I was in your boat too- wanted to make parts with an absolute minimum of futzing with the machine build itself- and Jeff Birt's kit came very highly recommended. It's about as close to a turnkey Taig setup as you can get, he hooks you up with all the software/config files/general setup crap you need, and he personally offers great support and troubleshooting once you're setting it up. What's your application anyway? I am always just tinkering with things that strike me as interesting, so the size isn't of any particular importance so long as it is reliable and high-quality.
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Sep 14, 2017 03:22
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shovelbum posted:Are there any good benchtop CNC milling options these days under $5000 that aren't more of a project in and of themselves than a machine tool? Would love to be able to fabricate small parts at home, but may just be a pipe dream. Sherline. You can see my Sherline mill in the post above yours. I'm about to retrofit it for CNC, but you can buy packages already kitted out.
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Sep 14, 2017 12:47
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 thank you for this
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Sep 14, 2017 20:31
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cakesmith handyman posted:
The Iowa fire control computer was an absolute masterpiece, doing calculus in 20 variables to hold 80 yards circular error probability for a 2600lb shell at 30 mile range. shame on an IGA fucked around with this message at 21:52 on Sep 14, 2017 |
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Sep 14, 2017 21:50
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oh man i did some digging and found the much more thorough technical document version of this https://synthetica.eng.uci.edu/mechanicaldesign101/Basic-Fire-Control-Mechanisms.pdf
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Sep 18, 2017 01:21
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Is there information on how much to torque hold downs for pieces on a mill? I was milling a flat piece of 1/2" aluminium plate today and noticed the more I torqued it down the more it deformed and thus 'bounced back' when I released the hold downs. I wanted to torque it down less with fewer clamps, but at the same time of course I don't want it flying across the room or hitting my midsection.
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Sep 21, 2017 11:46
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I believe the coefficient of friction is what you need to look up. AvE talks about it sometimes, and how you don't need to crank things down to hold workpieces because of it.
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Sep 21, 2017 12:45
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If you're working at home and not in a production environment where every single variable can be reliably controlled and fine-tuned, I suspect trying to calculation-level finesse fixture torque is a waste of time and effort. At my last job I spent a shitload of time troubleshooting the fixturing for a part we were doing a run of 500+ units of, also trying to manage springback plus the stock lifting off the tooling plate from the cutting forces, and we didn't even come close to picking up a torque wrench for the fasteners because all the other confounding weirdnesses (how badly the individual blank was saddled from the extruding mill, the down-to-the-thou thickness differences that lead to the supporting web holding fast or shearing, etc) made that a secondary factor. Not quite the same thing, ofc, but. Assuming this isn't a production thing, I would just trial-and-error something that works for you. try a different workholding approach more suited to thin stock that wants to deform or mix up your current setup to distribute the forces better and/or increase the friction on the whole part without increasing the deforming forces on the stock. It's also worth remembering you're on a mill and the potential kinetic energy in the work is much less than if it were chucked up in the lathe- torquing the part down "less than you're usually comfortable with" is something you can often do safely if you take a few extra safety precautions and machine conservatively at first, stepping it up as you confirm that the work isn't going anywhere. Not textbook best practice, but successfully and safely running a part after experimentally torquing the vise/clamps down way less than you're used to doing and assume you must do is very illustrative and gives you that intuitive/tactile sense of what's sufficient.
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Sep 21, 2017 16:21
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Speaking of fixturing I really want to buy some mitee-bites for flatter stock (https://www.miteebite.com/products/fixture-clamps/) but I just can't bring myself to spend $80 on 10 of what are essentially nuts and bolts.
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Sep 21, 2017 21:48
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Mitee bites work really well, but they tend to wear out really quickly. May not be as much of a problem if you don't have guys hulk tightening then down.
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Sep 21, 2017 21:52
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I've got a set of those and love them. Can't take a heavy cut but for making one face flat they're awesome.
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Sep 21, 2017 22:38
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rawrr posted:Speaking of fixturing I really want to buy some mitee-bites for flatter stock (https://www.miteebite.com/products/fixture-clamps/) but I just can't bring myself to spend $80 on 10 of what are essentially nuts and bolts. We have this one part at work we've been running for maybe 20 years, we have a fixture with those clamps on it. After every 500 pcs or so you need to replace the screw or the hex. They do work well, and if you're only using them occasionally you can get a lot of use put of them.
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Sep 21, 2017 23:21
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Ambrose Burnside posted:oh man i did some digging and found the much more thorough technical document version of this I've held a copy of this book in my hand. This and the 1944 "Airplane repairer's handbook" are absolute gold for mechanisms and machinery.
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Sep 22, 2017 02:28
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I've linked this before, but always a good time to revisit the procedures for bootstrapping NIST from three plates and a hand scraper. Wayne R. Moore: Fundamentals of Mechanical Accuracy (pdf, Moore Jig Borer Co.) IIRC this covers situations where lathe beds need to be corrected for the curvature of Earth. shame on an IGA fucked around with this message at 03:22 on Sep 22, 2017 |
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Sep 22, 2017 03:17
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I've heard about people making ersatz mitee-bites by just eccentrically turning the head of a SHCS down a little in a 4-jaw chuck/3-jaw with a shim under one jaw, turning it into a cam, and then cutting and drilling brass hex stock to make the washers. Worth a try, imo, although i haven't tried it myself.
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Sep 23, 2017 00:12
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I don't have a lathe - the bigger problem is that I don't really have space for one either :< Made a spindle lock (http://www.vinland.com/Taig-Spindle-Lock.html) for my lil Taig. I hated changing tools as it was always awkward as heck. Hoping that by combining this with depth collars for the tool bits (and standardizing shank size), I can make tool changes less of a hassle. 
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Sep 23, 2017 18:44
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that's smart! the two-wrench system is a pain and the stock wrenches are awkward. and yeah, the lack of easy tool-changing is an increasingly-big bummer for me, it discourages me from even writing programs that make use of more than one tool. These dudes used to make ER16-compatible tool holders for painless tool changes but stopped http://www.hightechsystemsllc.com/pt_rapid_changer.html - the silver lining is that they published free drawings of their designs, and they still seem to have inventory on hand. reading around online, some people have had bad experiences with 'em on account of runout and the toolholders spinning under high cutting forces, but that's apparently mostly down to their quality control. they updated their first version to a collet-retaining type that apparently runs truer at some point, but the toolholder type has a 1/2" toolholder, which opens a lot of doors irt using more widely-available commercial tooling like indexable carbide (albeit under the Taig's weird anemic operating conditions) e: hachi machi https://www.youtube.com/watch?v=6VFO6SOxcgw e^2: tbh depth collars do seem "infinitely simpler" to make and implement, though Ambrose Burnside fucked around with this message at 23:26 on Sep 23, 2017 |
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Sep 23, 2017 23:00
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That's pretty neat but I'd be too cheap to pay for it (and lazy to make it). My original plan was to do something similar by having spindle "extenders" where it's a complete ER16 holder with a female collet nut thread that threads onto the Taig spindle. There is actually an off the shelf solution similar to that, as Taig makes ER16 extenders that thread onto their older lathe spindle, and in one of their videos they show their CNC mill being used in this arrangement. I'm like you in that I found myself avoiding tool changes, and it's even trickled up to the design phase where I'll sometimes omit features or make holes larger than they need to so I can just machine it with the end mill. I suppose that's basically DFM and not an entirely bad thing I guess...
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Sep 24, 2017 00:22
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What's a tool change? https://www.youtube.com/watch?v=GcddvL4ZteI
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Sep 24, 2017 00:33
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I've heard of those solid ER16 holders but apparently the big downside is that they can't maintain effective tool length on account of having to be screwed on- if you don't apply the exact same torque every time the tool length can vary by an unnacceptably-high amount, enough to warrant checking the height offsets every tool-change and obviating the toolholder entirely. Depth collars are really straightforward and simple, my concern would be that you wouldn't be able to install them without at least a few thou variance in height. Which would be acceptable for a lot of jobs, so I might have to tackle something like that myself. Maybe a simple non-collet toolholder reamed to accept a 1/2" shank too, just to make facing without a flycutter more viable, that kind of thing. A lot of people instead rig up electronic height gages using conductive pads wired to the controller and add an offset-check macro to their programs after every change, so you change the tool the usual way without worrying about the height and it works poo poo out, which isn't a bad alternative. Ambrose Burnside fucked around with this message at 00:49 on Sep 24, 2017 |
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Sep 24, 2017 00:39
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There's also Nick Carter's approach, it works from the back instead of from the front like with depth collars and is pretty clever- http://www.cartertools.com/erss.html  Basically gives the Taig a pseudo-drawbar that runs from the pulley through to the spindle with a magnet set in the end- it creates a physical adjustable stop that tooling will butt up against, and a magnet to retain the tool at the exact correct height while you're futzing with the dumb double-wrenches. If you don't mind carving up your pulley with a tapped hole or two it seems like a really elegant solution to the Z-height issue. Ambrose Burnside fucked around with this message at 03:05 on Sep 24, 2017 |
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Sep 24, 2017 01:02
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How can you make your own pulleys (small, like GT2 printer pulleys) at home? I have a rotary table & mill and I understand how to cut them like a spur gear but I don't know where to get the cutting bits. Spur gear cutters are readily available on ebay but I can't find pulley cutters. I realise you can make your own from HSS and attach it to a fly cutter but I don't know how to grind the HSS accurately - some of the radii in the GT2 pulley profile are really small, like 1mm or less.
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Sep 24, 2017 08:19
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I'm doing a residential school to learn how to metalwork at the moment. Today I learnt how to mug weld which I need to practice a stack more with and also oxy weld which I'm not as good at but I think with more practice I can make it work well.
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Sep 24, 2017 13:05
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Mudfly posted:How can you make your own pulleys (small, like GT2 printer pulleys) at home? I have a rotary table & mill and I understand how to cut them like a spur gear but I don't know where to get the cutting bits. Spur gear cutters are readily available on ebay but I can't find pulley cutters. I realise you can make your own from HSS and attach it to a fly cutter but I don't know how to grind the HSS accurately - some of the radii in the GT2 pulley profile are really small, like 1mm or less. Why not just buy the ones you need?
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Sep 24, 2017 16:41
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shame on an IGA posted:What's a tool change? Theres a shop near me, my boss is friends with the owner. They have two of those Index machines. They are insane. I think they were like 2 million each?
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Sep 24, 2017 16:50
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So I picked up a 16HP dual speed three phase motor for free. Was thinking of making a solid state variable speed controller for it (As I'm an electrical engineer and that would be a good project for continually hating my life for a month) But then i'd need to find something to actually build with it. Almost seems too powerful for the size of mill that I could easily build, but I do want a 3 axis, or a lathe.
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Sep 24, 2017 17:12
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M_Gargantua posted:So I picked up a 16HP dual speed three phase motor for free. Was thinking of making a solid state variable speed controller for it (As I'm an electrical engineer and that would be a good project for continually hating my life for a month) Maybe find an old lathe in need of a spindle? The most practical thing I could think to do with it is turn it in to a generator. I cant think of any machine projects that'd warrant a motor that big that it wouldnt be hilariously cheaper just to buy a machine.
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Sep 24, 2017 20:09
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Marry it to a hydraulic pump and become the envy of your log-splitting friends
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Sep 24, 2017 20:29
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