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I got asked to teach half of tomorrow's class because it's on chasing/repousse and I have more experience than the instructor  good thing I got that post from the OP to re, ah, hm. hmmm.
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Feb 23, 2015 23:50
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Slung Blade posted:I use that technique on all my twists, which are always crooked because I use a single handle wrench to turn them. Come on now, you haven't made your own two handled turning jig yet? One of my bazillion on going projects is a motorized jig with either swappable inserts for stock diameters or a pneumatic chuck.
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Feb 24, 2015 04:05
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Two vicegrips also work pretty dang well, if a little unwieldy.
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Feb 24, 2015 04:54
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Ambrose Burnside posted:
 Kasan posted:Come on now, you haven't made your own two handled turning jig yet? One of my bazillion on going projects is a motorized jig with either swappable inserts for stock diameters or a pneumatic chuck. Nope. Sometimes I use two wrenches on opposite sides though, if I can find them both when I need them.
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Feb 24, 2015 07:14
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Finished the leaf I was doing as the demo example. Turned into more of an, idk, sacred pepper thing, but whatevs man, whatevs 
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Feb 27, 2015 01:33
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I like the majesty coming off it.
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Feb 27, 2015 09:50
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ReelBigLizard posted:I like the majesty coming off it. I'd hang it on my wall for sure.
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Feb 28, 2015 09:29
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I want to shoop that pepper into some sort of Byzantine mural where it belongs, but I'm also very lazy. 
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Feb 28, 2015 09:41
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Ambrose Burnside posted:Finished the leaf I was doing as the demo example. Turned into more of an, idk, sacred pepper thing, but whatevs man, whatevs
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Mar 1, 2015 10:03
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it's chased and repoussed copper (looks silverey cause lighting was bad). Repousse's a sheet metal technique where you set the metal in a supporting medium like pitch and raise a design or pattern from the reverse with shaped punches; chasing is similar, but performed on the front. It's an obscure and rarely-practiced discipline now because it's very time-consuming and (unlike casting or conventional jewellery fabrication methods) doesn't scale to larger production runs, but with the technique you can produce designs unachievable with any other method. for that leaf I drew a simple leaf on the sheet of copper with soapstone, traced it with liners (blunt chisel type tools) that "draw" the pattern in the metal in a way you can see from the reverse, sunk it with round repousse punches, flipped it over and fined up the face and added lots of embellishments with chasing tools. whole process took maybe, idk, 5-7 hours I'd guess I've been working on a big write up for the OP for, like, 6 months or something stupid like that, it'll get done and posted sooner or later
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Mar 1, 2015 17:42
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Ambrose Burnside posted:it's chased and repoussed copper (looks silverey cause lighting was bad). Repousse's a sheet metal technique where you set the metal in a supporting medium like pitch and raise a design or pattern from the reverse with shaped punches; chasing is similar, but performed on the front. It's an obscure and rarely-practiced discipline now because it's very time-consuming and (unlike casting or conventional jewellery fabrication methods) doesn't scale to larger production runs, but with the technique you can produce designs unachievable with any other method. 
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Mar 1, 2015 18:08
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https://www.youtube.com/watch?v=IZMwpT8BMw8 Here is a video of a silversmith doing a demo of the technique. She also has a good anticlastic raising video as well, which is what I am working on at the moment.
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Mar 1, 2015 18:47
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I wonder if you can practice this on the cheap by just taking aluminum foil and folding it until it's 1/16th thick or so, then hammer it smooth with a tack hammer or smooth faced deadblow. Edit: Or maybe those foil baking dishes you can buy for $1/3 most places? Kasan fucked around with this message at 21:27 on Mar 1, 2015 |
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Mar 1, 2015 21:23
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No, you cannot  actually working on found objects like baking dishes does fine, the catch being that cheapie dollar store models would be made of plated steel or mayyyyybe aluminium, neither of which are particularly desirable. I have seen chased intact beer cans worked like hollowware, tho. If i decide to play around and experiment I waste, like, a dollars' worth of sheet that might still be salvageable for something else, just pony up for the real thing. e: Also those old pewter mugs you can get for like $3 at goodwill are extremely excellent for chasing practice, pewter's a gorgeous metal to work on. Fill the cup up with pitch and chase as-is or cut the sides out for use as a small section of sheet. Ambrose Burnside fucked around with this message at 17:47 on Mar 2, 2015 |
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Mar 1, 2015 23:29
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I spent the weekend learning a different kind of metalwork (because lead is a metal).    MY GIRLFRIEND's mother is doing new windows for their front door and I offered to help in exchange for her teaching me how.
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Mar 2, 2015 10:53
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I think I'm gonna pick up the stock to build a jeweller's hydraulic press this week. I have engineer-approved plans for a 20-ton press that uses 1" threaded bar and plates- if I wanted to up it to a 25-ton ram, which seems necessary for the bigger stuff + embossing I'd likely wanna do, bumping the stock sizes up to 1-1/4"- 25% stock thickness increase for 25% working force increase- would probably do just fine, right?
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Mar 2, 2015 17:55
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Ambrose Burnside posted:I have engineer-approved plans for a 20-ton press that uses 1" threaded bar and plates  Seriously, that's next on my to-build/buy list.
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Mar 2, 2015 18:10
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I won't have access to the book they're in- Nancy Megan Corwin's Chasing and Repoussé: Methods Ancient and Modern- for another week or so, but it's a really dead-simple weldless design- IIRC it's just two 1" 6x8-ish plates with holes drilled in the corners, four 1" threaded rods with a bunch of matching nuts, 1" ID tubing to go over the threaded rods, 1" springs for hydraulic ram return, and a platen with four corner holes sized to ride on the tubing plus holes drilled into the face to accept Bonny Doon accessories. Once the holes are drilled you just assemble it real simple-like, installing the plates at either end of the rods with the nuts with the platen/tubing/springs riding between them and popping the hydraulic jack between the bottom plate and platen. I forget how the jack attaches to the press components itself, I'll post the deets once I have access again. E: Don't wanna be violating no  rules so maybe posting the actual schematics for the Bonny Doon hole pattern aren't kosher, but a very similar sort of thing is described in this Ganoksin article http://www.ganoksin.com/borisat/nenam/practical-die-forming.htm with the caveat that the article author makes use of significantly lighter stock than Corwin's certified-safe design does, and also probably never pushed their bolt-together press too hard because they almost exclusively talk about making male-female conforming dies, which operate at the lower typical-use pressures of jeweller's presses.
Ambrose Burnside fucked around with this message at 18:47 on Mar 2, 2015 |
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Mar 2, 2015 18:29
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Ambrose Burnside posted:I think I'm gonna pick up the stock to build a jeweller's hydraulic press this week. I have engineer-approved plans for a 20-ton press that uses 1" threaded bar and plates- if I wanted to up it to a 25-ton ram, which seems necessary for the bigger stuff + embossing I'd likely wanna do, bumping the stock sizes up to 1-1/4"- 25% stock thickness increase for 25% working force increase- would probably do just fine, right? Depends on how the bars are oriented. If they're taking axial force, strength will increase with the area, or the square of the diameter. 1.56 times the original. So that's fine. If they're taking bending loads, then strength increases with either the third or fourth power of the diameter, depending on if you've got yield or deflection limits: deflection decreases inverse to the moment of inertia, which is proportional to the fourth power. Maximum stress under bending loads, though, decreases inverse to the moment of inertia times the radius, so the third power of diameter. Any way you dice the numbers, you should be okay. Your numbers are conservative, and I'm going to say that's a good idea, because factor of safety. TL;DR: Yeah, that should be fine.
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Mar 3, 2015 01:13
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ReelBigLizard posted:
How to build a 100 ton Press for machining, broac…: http://youtu.be/d_LSPX8cNaE
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Mar 3, 2015 16:08
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1" stock for 100 supposed tons of press. Next video in the series: structural failure of the press 
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Mar 3, 2015 16:17
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Ambrose Burnside posted:1" stock for 100 supposed tons of press. Next video in the series: structural failure of the press He tried to do 100 tons, but turns out it's only maybe 70 max. Whoops.
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Mar 3, 2015 23:29
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Geirskogul posted:He tried to do 100 tons, but turns out it's only maybe 70 max. Whoops. That makes more sense since 1" cube of steel is rated at something like 72kpsi which is what, 36 tons?
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Mar 3, 2015 23:35
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Kasan posted:That makes more sense since 1" cube of steel is rated at something like 72kpsi which is what, 36 tons? Several problems with this, though. First, the force isn't concentrated equally along the whole bar: it's applied along the threads, which is going to be a smaller area. Furthermore, the threads are going to give stress concentrations, which could very easily raise it above yield. Third, it ignores any other forces on the design: I'm wondering about how the shear force from friction on the threads when turning is going to interact with the axial load. The friction will also cause the bolts to wear out pretty quickly, and I didn't see him put thread lube on the actual threads. Running some very simple math based on grade 8 steel at 150 kpsi and solid rods, I'm only getting 236 tons, which is not enough of a factor of safety in my mind. Aerospace does around 2, and there's a reason they spend literally years analyzing forces. I'd say aim for a factor of safety of 5 to 10, which makes a 25 ton press just about right IF you buy the grade 8 rods.
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Mar 4, 2015 03:09
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Given his rants about wearing gloves and getting drunk while running the lathe, safety probably isn't his biggest concern with this design. 
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Mar 4, 2015 03:31
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Personally I was digging the dies affixed to the flat platens with neodymium magnets, the sort of tool holder that will operate properly at safe pressures and do absolutely nothing when it actually counts.
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Mar 4, 2015 03:52
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Ambrose Burnside posted:Personally I was digging the dies affixed to the flat platens with neodymium magnets, the sort of tool holder that will operate properly at safe pressures and do absolutely nothing when it actually counts. Since all the loading is normal to the face of the part, slippage shouldn't be too huge an issue? I thought it was a pretty clever way to mount the thing. Unsafe as gently caress, but clever. I'm eagerly awaiting followup where he either cracks it, or turns part of it into a short piece of ballista arm and launches something across the shop.
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Mar 4, 2015 18:24
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Ok, so I don't get why he used threaded rod & tapped the base to accept them. Doesn't the hydrolic ram provide the pressure? Or is this a case where they are going to advance the threads one by one to gently ease it in?
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Mar 4, 2015 19:05
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As far as I can tell he operates it by gradually turning the rods in sequence. Thus keeping it cheap.
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Mar 4, 2015 19:51
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Ambrose I'm very jealous. You're right about the breaks being important; I try to work no more than two pieces at a time, because by the third (9th) heat, I'm exhausted. I've been trying to forge all winter, but we've had an epic amount of snow and sometimes it's not even worth the effort to get out to the shop. However, forging in winter is amazing. I don't get all sweaty, and snowballs are perfect for cooling off handles that are heating up. My home made forge still doesn't get hot enough to forge weld, but I'm about to build a new one so hopefully I'll see some improvement. Question - I found a 205 lb Hay Budden anvil on CL. Posting is down, but it looks to be in good shape. Anvil + 100 lb stand : $675; Worth it? Pagan fucked around with this message at 13:17 on Mar 6, 2015 |
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Mar 6, 2015 13:05
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Pagan posted:Ambrose I'm very jealous. You're right about the breaks being important; I try to work no more than two pieces at a time, because by the third (9th) heat, I'm exhausted. Forging in the snow requires the right soundtrack. https://www.youtube.com/watch?v=9j6nyEcIk98
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Mar 6, 2015 15:57
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Pagan posted:Ambrose I'm very jealous. You're right about the breaks being important; I try to work no more than two pieces at a time, because by the third (9th) heat, I'm exhausted. Granted I do not know all that much about anvils, I remember reading that you did not want to pay more than $1.** per pound of anvil. Maybe that's changed though.
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Mar 6, 2015 16:24
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Tamir Lenk posted:Forging in the snow requires the right soundtrack. Not that I look anything like Conan, but I feel like this sometimes. I may be a nerd, but I'm a nerd who forges glowing hot steel in the howling depths of winter. The RECAPITATOR posted:Granted I do not know all that much about anvils, I remember reading that you did not want to pay more than $1.** per pound of anvil. Maybe that's changed though. I thought that too, until a Google search of Hay Budden Anvil turned up things like "Cadillac of anvils" and "best american made anvils of the 1900's." But that's why I'm asking the experts here before I spend the money.
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Mar 6, 2015 22:51
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Pagan posted:Not that I look anything like Conan, but I feel like this sometimes. I may be a nerd, but I'm a nerd who forges glowing hot steel in the howling depths of winter. Also anvils over 130lbs or so come with an entire additional premium of their own, they're much harder to come by. Large anvils are pricey as gently caress and new ones are 10x worse. A new 200lb class anvil from centaur forge runs you ~1100 bucks, plus shipping and god only knows what that'll run. You're looking at a high-quality anvil plus a large heavy stand for less than half what a new one'd run you. If you've got the scratch and the anvil is in good-to-great shape, I'd do it.
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Mar 7, 2015 18:46
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A dollar per pound was valid in 1997, maybe. If it's in good shape (no cracks, horn is intact, nothing wedged in the hardy until the end of time) and rings OK, I'd be all over it at that price. Especially with the stand. Is that fabricated steel? Wood?
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Mar 9, 2015 22:07
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Slung Blade posted:A dollar per pound was valid in 1997, maybe.   Stand is fabricated steel, all welded together. Anvil is in good shape; looks like someone used a plasma cutter near the back at some point, but otherwise it's in good shape. Getting it out of my SUV was fun, but the guy who sold it said "Think like the Egyptians." A stack of 4x4 scrap lumber and some planks gave us a sturdy inclined plane and that made it surprisingly easy. Once I got it in the garage I fired up my forge for a quick session, and I was in heaven. This was worth every penny. So much space and so much weight, and it sounds great, too. I have a scrap steel that has proven really hard to work (red hard I believe is the term) but I had no problems forging it on this anvil.
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Mar 10, 2015 02:20
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Hmm, looks like someone resurfaced that with hard faced welding rod, there's a bit of a dome on it there. Might just be illusion. Being resurfaced is not necessarily a bad thing though. I might get the face milled down a touch to have a good flat baseline to work from, but I'm sure it's fine. Long as they heated it up when they did it, it'll be fine. Can you see any tiny cracks in the face?
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Mar 10, 2015 21:44
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Slung Blade posted:Hmm, looks like someone resurfaced that with hard faced welding rod, there's a bit of a dome on it there. Might just be illusion. I cannot, it looks pretty smooth and even. It is perfectly flat across the top, I think it's just the chipping around the edges that make it looked curved.
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Mar 11, 2015 02:34
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Karia posted:Drilling such thin sheet with a relatively big drill is going to be hard, it'll just bend and if you punch through it won't make a full hole, the bit'll catch the sharp edges and drag your tool down and the part up, potentially throwing it. Not fun. One thing you could try is taping the sheet down to a sacrificial block so that it'll be more rigid and you can actually get a full hole. We use double sided carpet tape, and while I haven't tried it for this application, it should work. Alternatively just clamp it down to a sacrificial block right by your cut. Closing the loop on this drilling into spring steel question. 320rpm with backing board and fresh bit and we were making long spirals like it was butter. Thanks for the tips dudes!
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Mar 11, 2015 02:56
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Pagan posted:I cannot, it looks pretty smooth and even. It is perfectly flat across the top, I think it's just the chipping around the edges that make it looked curved. Alright, cool. The plasma cutter scarring made it look like welding voids I guess. Either way, I think you got a great deal on a great anvil there. I'd probably smooth out the edges, but I'm spergy about stuff like that.
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Mar 11, 2015 16:25
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