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My parting tool just led to tons of chatter. I actually used a small spindle gouge a lot, I think taking off such a minuscule amount of material combined with being able to roll it back and forth worked really well. I cut with the back most part of the edge with the gouge rolled way over for that. But definitely the file for roughing it down, and for making sure I removed metal in equal amounts to wood so it’d keep a smooth transition.
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Dec 26, 2020 00:30
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Hand turning brass seems dangerous AF
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Dec 26, 2020 01:16
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https://www.youtube.com/watch?v=SpVBjjdEoPA
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Dec 26, 2020 07:53
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long time no see, metalworking thread. here's something a little different for me- i play paintball, a goofy game for teenagers and the poorly-socialized adults they often grow into. I have a goofy impractical affectation gun, and would like to make it even less practical + more of an affectation i roll with a stock class CCI phantom pump gun. it's an old-school design with internals based on the first bolt-action Nelson guns intended as tools for cattle marking. very stripped-down, clean design, with a closed bolt that shoots accurately and with consistent velocity by paintball standards. the pump part means no semi-automatic fire, while the stock-class part means means "stock to the original 1980s paintball gun configuration of no semi auto, no bulk hoppers, no bulk gas". i don't use a 200-round bulk paintball hopper or big shoot-all-day CO2/HPA tanks, but rather a 10-round internal tube magazine and 12-gram CO2 quick-changer that give me ~30-35 consistent shots per powerlet. it puts me at a significant disadvantage to standard semi-auto players but it's a very fun way to play (also it gets the paintball greybeards to stop by and gimme props for the little piece of nostalgia every time i take it out for an evening) i dont have any pictures of my setup but this one from google's p close, just get rid of the transparent acrylic parts and add a steel tube L-stock  anyways: there are these fancy paintballs called First Strike rounds (FSRs) which are little engineered spin-stabilized paint-filled .68-calibre projectiles, iirc theyre patterned on grenade designs for smoothbore grenade launchers  they perform dramatically better than conventional spherical paintballs, offering 3-4x the effective range and maybe 10x tighter groupings at medium-long ranges. they also cost way more than conventional paintballs, like $0.15+ per round, and their shape means they do not work in standard paintball guns with loading systems and breeches designed to handle spherical projectiles. i do not have a First Strike-ready paintball gun and probably never will because they cost a shitload ...turns out there's an established method for modifying a phantom breech to become First-Strike compatible, and all it requires is some basic modification of the breech to end up with a bolt-action, breech-loading single-shot gun capable of firing either First Strike or conventional paintballs this is how the phantom (plus all other nelson-based closed-bolt guns) works internally:  to make a single-shot breechloader you mill the feed-neck and/or the breech port away to accomodate the FSR's profile, remove the pump handle and linkage, stick a bolt handle into the bolt using the hole the pump linkage normally connects to, and then cut a shaped slot in the breech to constrain the bolt handle's travel, with w notches at appropriate points to let you lock the bolt in the forward position, more or less how a real bolt action works, just much lighter-weight in construction b/c the forces involved are much lower  this example modifies the breech as little as possible, which helps keep debris out from in between the bolt and power tube/hammer, but feeding looks slow/tricky  here's the other way i could go, cutting away the entire top half of the breech to help guide rounds into the breech, in exchange for a weaker breech and an action that probably fouls v easily i have misgivings about how any modification like this exposes the gas tube and hammer assembly to dirt and grit, so I'd definitely want to work out a dust shield/port cover that shields the open breech + bolt handle slot to the greatest possible extent. based on how these parts seem to get implemented with real firearms, i'm thinking either a hinged plate that I manually flip up and to the side as I load a round, or a sliding cover linked to the bolt handle (by passing the handle through a hole in the cover, or by using a spring to push it against the base of the bolt handle) that automatically slides back and forth parallel to the breech tube to cover it for every moment i'm not loading a round or working the bolt i dont wanna gently caress up my existing gun but fortunately i can just buy another breech tube from the manufacturer for like $40 and modify that to suit, then switch it in for the original breech if i wanna be a fancy lad and stoically hurt our teams chance of winning even more than i do currently e: i'm getting ahead of myself here, but as a stretch goal + to build on a breechloading conversion, i'd like to work out a First Strike-capable "magfeed adapter", which effectively converts a gun to accept firearm-style spring-fed magazines instead of the usual bulk hopper or stock tubes. it's functionally a magwell body that accepts commercially-available paintball-feeding magazines and feeds them correctly into the breech of a gun not originally designed to work that way. this would let me shoot those fancy First Strike rounds from the normal pump configuration, and instead of being a single-shot breechloader it'll load magazines holding 5-20 FSRs and will shoot as fast as I can pump while holding the trigger down. mag-feeding is also much more reliable than the gravity-dependent 'rock and cock' stock-class technique, and will feed correctly in any position. in principle, anyways. getting it to feed consistently is definitely gonna be the trickiest part of this, and where most other attempts have fallen down, so i'll keep it simple with top-loading magazines that feed directly into the breech along a straight feed path, think sth that looks like a Bren gun. it makes loading inconvenient and interferes with mounting a sight but almost every attempt i've seen to convert Phantoms to magfeeding FSRs has failed because they try to feed rounds up from the bottom around the side of the gun, and then through a 180o elbow down into the breech, and they never quite get the feeding reliable enough to be useful for play. the original Phantom designer worked on conventional frame-integrated bottom-loading magwells for like 5 years and gave up after failing to find an acceptable way to implement it, phantoms are designed too sparely to have room for it and you'd have to completely redesign the gun to facilitate it any magfeed adapter would probably get 3D printed, though, so technically out of scope for this thread i guess. Ambrose Burnside fucked around with this message at 21:55 on Dec 29, 2020 |
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Dec 29, 2020 21:28
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...and for something that's more on brand, I've been away from my shared shop space for a month because covid was working its way through the other tenants there. i was planning on handmaking a bunch of gifts, which i did not do, and must now do in the next couple of days. gently caress. any ideas for quick and easy gift-suitable projects making use of heavy-gauge copper wire (.125" - .15" dia)? I bought a shitload of it a while back and I can't do hotworking of steel/titanium rn (I can still torch-anneal) so i think some cold-worked trinkets are in order, but the only thing that comes to mind are spring-closed S-hooks for keychains, or keychains in and of themselves, probably showing off an inch or two of some exotic twist that I can execute in miniature without the benefit of steel's spot-heating amenability as an added bonus, copper is a broad-spectrum antimicrobial that continually self-sterilizes and kills microbes on contact with skin/belongings, and which doesnt contribute to antibacterial resistance. thank sth called the oligodynamic effect ( https://en.wikipedia.org/wiki/Oligodynamic_effect ), which actually applies to many metals that are denser and nobler than steel/aluminium inc. brass, silver, gold etc. so i was thinking of framing keychain components or simple copper charms as a sort of hand-cleaning, COVID-neutralizing fidget-charm. like rosary beads except they actually, you know, work as advertised. with the antimicrobial thing in mind, are there any other potential gifts for the pandemic holiday season that people might appreciate getting? bonus points for stuff i can execute quick n dirty.
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Dec 29, 2020 22:08
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I've seen people with keychain hooks for opening doors / pressing elevator buttons / entering pin numbers and the like. Also pump action riffled paintball gun sounds awesome. I can see where the bottom mag wouldn't work, could a side feeding mag do better? Hell anything but straight up would allow for an easier sight and if they're that much more accurate, paintball sniper.
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Dec 30, 2020 01:31
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self-sterilizing door-openers/button-pressers, that's good, thanks and yeah fortunately the manufacturer makes offset breeches that would let you load mags at a~30deg. angle away from vertical, which should be enough to let you stick a weaver or picatinny rail down the centerline of the breech. here's a comparable offset-vertical mag adapter someone made for a different gun, seems to leave plenty of room for a sight like i said, tho, gettin hella ahead of myself Ambrose Burnside fucked around with this message at 06:14 on Dec 30, 2020 |
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Dec 30, 2020 02:41
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I'm making a welding workbench with 2"'x2" square steel tubing for the legs. I want some sort of adjustable feet on it because my floors aren't level. I've been looking at stuff like: https://www.amazon.com/dp/B07MKPXSYK/ There's a lot in this style. I figure I'd just weld them to the side of the leg at the bottom. I don't really like that the foot would be offset from the leg to the outside though. https://www.amazon.com/dp/B07P5WTWH6/ These look like they could maybe go inside the leg, which I'd prefer. Any better options or suggestions? Should I just weld a nut on a plate and weld that to the bottom of the legs? A separate question: What fan should I buy to ventilate my basement workshop? I'll be doing some mig welding, 3d printing, and occasionally stick welding. I plan to mount the fan in a bracket and duct the exhaust out through the exterior wall. I've been browsing fans and fume extractors but I haven't read anything in terms of what volume of cfm or partiflcular model of fan is a good solution for getting welding fumes out of an interior workspace. Any suggestions? Is there one that is the standard?
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Dec 30, 2020 22:32
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https://www.mcmaster.com/leveling-feet/nickel-plated-steel-swivel-leveling-mounts-with-threaded-stud/ I bought these for a tubing bender stand thingy and they worked great. A little more than amazon but I've got a lot more faith they'll hold their rated weight. For fume extraction maybe a range hood over the welding table?
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Dec 31, 2020 00:51
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honda whisperer posted:https://www.mcmaster.com/leveling-feet/nickel-plated-steel-swivel-leveling-mounts-with-threaded-stud/ Ok, heavy duty feet ordered from McMaster-carr. Thanks for the link!
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Dec 31, 2020 06:43
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Vim Fuego posted:Ok, heavy duty feet ordered from McMaster-carr. Thanks for the link! Good choice. I learned my lesson with cheap leveling feet the hard way after building some small tool stands out of 1-1/2" tubing - they work, but had I built anything heavier or larger they would probably fail. As far as fume extraction it depends on the size of the space and how close your ventilation is to the fume source. You could maybe get away with an 8" ventilation unit hooked up to ducting for general ventilation. You might also look into portable fume extraction units for at source extraction - they're expensive but worth it if you plan on welding more than occasionally. I also highly recommend wearing a respirator when welding or grinding metal indoors (or anywhere, really). Here's what AWS and OSHA have to say about ventilation in regards to welding: https://www.aws.org/resources/detail/dealing-with-welding-fumes https://www.osha.gov/Publications/OSHA_FS-3647_Welding.html If you really want to go down the rabbit hole, you can dig into OSHA standard 1926 of which subpart J (1926.353) regards ventilation for welding/cutting processes.
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Dec 31, 2020 10:30
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Thanks for the links! I read through a bit of them. Honestly I'm not going to be doing a large amount of welding. It'll be occasional. But I want effective ventilation to get the fumes out of the house. Right now I've got nothing, so something will be better than nothing. I'll probably end up going for something moderately priced and quiet. Likely a variable speed control will be nice to have. I found what looks like some good discussion here: https://forum.weldingtipsandtricks.com/viewtopic.php?f=2&t=14409 A rule of thumb appears to be 6-10 air exchanges per hour, so I'll calculate CFM based on that. But it's hobby usage, it's not a fabrication facility.
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Dec 31, 2020 12:10
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I rigged a "fume extractor" up exactly like you're talking about when i expected to be doing a lot of hotwork like soldering etc indoors. I passed some 6" round duct through an exterior wall, added an inline booster just inside the house to create a proper draught, and then finished it with a section of flexible duct to allow repositioning + a square-to-round reducer at the business end to act like a hood and help control where it draws from it works great, it can handle any degree of smoky work within the bounds of what's sane to do inside an ordinary residential structure (i.e. no welding), but tbh it's massive overkill for anything less than "this is my work and i do it every day", i don't use it nearly often enough to justify the work that went in there. another more sinister + subtle consequence of great indoor fume extraction is that you might start attempting increasingly-ambitious hotwork indoors b/c the smoke is no longer a constant "maybe you should work in the garage" push factor e: if i were to go back and do it all over again, i would probably go a lot simpler while still ejecting smoke n fumes straight outside, sth like using just a booster fan + flexiduct to push air out of the nearest convenient window, and i'd cut a storm window insert from acrylic sheet with passthroughs n fastener holes for the duct so i can use it in any weather and to generally end up with a professional and secure setup come to think of it, i'd try to use a coupler for joining the duct to the window insert so you can pull the duct down quick n easy when you're done working, there are magnetic ones intended for dryer vents that seem like an excellent fit for this sort of thing 
Ambrose Burnside fucked around with this message at 16:29 on Dec 31, 2020 |
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Dec 31, 2020 16:18
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can anybody vouch for anything you could describe as a "powered jeweller's saw" that isn't absurdly expensive and/or a piece of poo poo to use? ideally accepting standard 5" jeweller's sawblades but proprietary/other blades are fine as long as i can get em with very tine teeth for thinner gauges of sheet metal (up to ~26 ga) - Knew concepts makes the only saws that are explicitly this that im aware of, and they're apparently fantastic, but the price tag (over $2000 USD) makes it a non-starter. - proxxon offers a scrollsaw that meets this description and which is reasonably-cheap, but the reviews for it seem very negative in multiple regards. - the microlux multi-saw looks like a revised version of the proxxon saw they no longer sell, and although it seems somewhat better, the amazon reviews still suck and it'd also be a lot more expensive for me to get a hold of (no canadian vendors so i'd have to get it shipped from the US) - dremel's motosaw is a very affordable ($~125) lightweight hybrid scrollsaw-coping saw thing that seems to mostly fit the bill, except the 4" pinned blades it takes are poorly-supported and only seem to be offered in fairly low TPIs that limit you to sheet metal 20ga or thicker, which is a problem for me so yeah if anybody has any experience w any of these feel free to post about it, i suspect the microlux saw might be the best fit but a couple hundred bucks is a lot for me right now so i'm v leery of rolling the dice
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Jan 3, 2021 03:12
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triplepost sunday night special: i was reading about thermites, as one does- did you know that mixed-metal grinder swarf/dust, the sort created by grinding both aluminium and another metal like steel in the same space without cleaning in between, can unintentionally form thermite mixtures with a small enough particulate size from the grinders potentially making it unusually easy to ignite, so a small/manageable wastebin fire or stray welding slag/sparks can be sufficient to preheat and/or ignite the mixture, no magnesium/potassium perchlorate ignition needed?- and i realized that iron thermites produce extremely pure and soft iron, the sort that is commercially-obsolete and very difficult to obtain. for years i tried to source soft iron from non-antique/salvage wrought iron sources and never found anything that I could buy as dimensional stock by the pound vs., say, non-starter laboratory/research materials that are 100x needlessly-purer and 100x more expensive than conventional steel. thermite seems to be the only cheap, low-barrier route to producing your own carbon-free soft iron aside from, like, a bloomery furnace sth else similarly-intense. I read around a bit and found some people on iforgeiron who've worked with thermite-produced iron billets and could speak to the weirdnesses of the material ( very soft but absolutely gigantic grain size, for example); has anybody here ever done anything with thermite that's similar to this- train track rail welding, copper cadwelding, casting thermite into moulds, etc - who can speak to it? Ambrose Burnside fucked around with this message at 04:50 on Jan 4, 2021 |
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Jan 4, 2021 04:20
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i hadn't heard that bit about copper oxide thermites being more energetic so i went looking and found this https://www.youtube.com/watch?v=CrG1n7Av_z8 how old are these kids 
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Jan 4, 2021 04:29
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honda whisperer posted:I've seen people with keychain hooks for opening doors / pressing elevator buttons / entering pin numbers and the like. took a crack at these door opener tools using .155" copper wire, extensively work-hardened (seems plenty stout for this application, from the prototypes i've screwed around with). don't have my full shop access or my materials so i'm kind of playing w the materials i ahve on my tiny bench anvil and working stuff out  maybe idk 75% done i'd say? still have to add a twist or cut/graved decoration for the shank, needs pickling, planishing n polishing. i wanna put a lil conductive rubber boot over the "tip" so you can use it for a smartphone but havent sourced those yet. also tempted to scroll the 'hook' tip, but declining b/c it'll snag on everything even if it looks sweet Ambrose Burnside fucked around with this message at 07:01 on Jan 4, 2021 |
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Jan 4, 2021 05:13
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Hum, this popped up for 100€ real close to me. I wonder if it's worth it. Looks to be substansially built. Probably built soon after WW2 by Strömberg here in Vaasa, they are mostly known for making induction motors, this was probably something they did for a very short time after the war. Capacity looks rather limited, and those rpm speeds can't be serious, wonder if the last zero is supposed to be a decimal.  
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Jan 4, 2021 11:01
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I also didn't get to the first post but with all that wire you want to use up I'd suggest making treble clef hooks or something similar, anything decorative using one single piece no joins. Not too much hammering on any one portion so you don't have to keep worrying about hardening as much and makes a nice little decorative gift. Flatten the arcs to flare it out, flatten one or two small points in the middle to give you space for a nail hole.
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Jan 4, 2021 16:31
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His Divine Shadow posted:Hum, this popped up for 100€ real close to me. I wonder if it's worth it. Looks to be substansially built. Probably built soon after WW2 by Strömberg here in Vaasa, they are mostly known for making induction motors, this was probably something they did for a very short time after the war. Capacity looks rather limited, and those rpm speeds can't be serious, wonder if the last zero is supposed to be a decimal. It's possible those numbers are real. That looks a lot like a sensitive drill press. When you're down in the sub 2mm drill range, you need a zillion RPMS and very sensitive feed. Kinda looks similar to this: https://goldmachinery.com/machinery/2184.htm
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Jan 4, 2021 20:26
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Question about welder duty cycle. I know what it is, like how long you can weld per 10 minutes before you have to let it rest and all that. Question is, this: How do you figure out how long you've welded before letting it rest? Like when you're making sparks, do you count the seconds away and add them up to figure out how long you've been welding for? I can see that being practical if you're running long beads, but not so much if you're doing a whole bunch of short ones. Do you just weld for a while and then pretty much be all like "well thats probably been X minutes, so its time to cool down"?
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Jan 5, 2021 00:01
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My tig will shut itself off. Well not off, the fans keep going, and a little thermometer light comes on. Once that's off I'm good again. Idk if overheat protection is standard though.
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Jan 5, 2021 00:12
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Pretty sure my little Hobart 140 MIG does the same thing. Output stops, cooling fan runs, thermometer light comes on.
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Jan 5, 2021 00:15
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wesleywillis posted:Question about welder duty cycle. It's pretty obvious to me that when things start turning into a spatterfest it's time to stop welding. At least on any of the little boxes I've used.
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Jan 5, 2021 01:13
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Ambrose Burnside posted:I read around a bit and found some people on iforgeiron who've worked with thermite-produced iron billets and could speak to the weirdnesses of the material ( very soft but absolutely gigantic grain size, for example); has anybody here ever done anything with thermite that's similar to this- train track rail welding, copper cadwelding, casting thermite into moulds, etc - who can speak to it? I've done this before, using iron sand. Our technique was to take two small clay flower pots, one nested inside the other. The inner pot generally cracks during the burn, but the outer pot holds things together long enough for it to complete. Cover the hole in the bottom of the pot with a small piece of aluminum foil, fill it roughly two-thirds full of thermite, place in a sand pile and light it off with a sparkler. The iron melts through the foil and runs out the bottom, where it can be collected from the sand after a suitable period of cooling off. Here, have some incredibly bad pictures showing parts of this process. The still-glowing remains of a couple of pots next to the output of their burn on the right. Most of that glowing stuff is slag; the actual iron is underneath it:  The actual iron button extracted from the slag:  The output of a few burns, flattened and ready to be forge-welded:  Regarding the material itself, it's very ductile and easy to work. That said, I found it fairly difficult to forge-weld; it needs to get much hotter than steel before it sticks. Here's a billet of the stuff that's been folded a few times but haven't found the time to properly clean up - note the poor welds and inclusions:  Bonus shot - here's a steel (not iron) button made out of the same iron sand,with a graphite clay crucible. These end up in the cast-iron range of carbon content (~4%), so they can't be used directly. At some point I should try welding them up with some pure iron and see if I can get something useful. 
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Jan 5, 2021 02:14
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hell yeah dude, that rules. thanks for being thorough. the reason i care about soft iron is that it's well-suited to the chasing & repousse process, it needs soft ductile metals and even low-carbon steel is too hard & springy to be suitable. historically wrought iron chasing, cold and mounted in a pitchbowl, was commonplace but that sort of work has mostly disappeared b/c steel really needs to be worked hot to deform it significantly with punches. blacksmiths chase stuff with chisels and punches, of course, but it's a rather different beast
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Jan 5, 2021 05:38
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I want to try cutting some very small one- and two-part hammer-struck forging dies for the miniature titanium forgings i've been working on. i'm working with 0.125" and 0.155" dia CP2 alloy round bar, currently forged hot with just hammer & anvil. I'm mostly interested in simple dies to aid in squaring-up and tapering the ends of bars to a consistent standard; at this scale precise hammer-blows are very difficult to land consistently, and I struggle to keep my squares square and not parallelograms despite being able to hammer out perfect square tapers from bigger 1/2" bar all day long. I plan on hand-cutting the first dies by hand with conventional and/or diamond files, and then tempering (if necessary) with a plumber's torch, which isn't as unreasonable as it sounds b/c at this scale the entire die billet is gonna be, like, 1"x1" x 0.25" or something equally lilliputian, and the simple die impressions will be V-grooves or tapering V-grooves so it'll be straightforward to form with needle files. also i'm not making real production tooling that has to hold up to half a million press cycles and is in constant use, i'd probably work on batches of a couple dozen parts with lots of downtime in-between die uses, so I'd expect to be able to manage the die temperature just through 'duty cycle', i'm mostly concerned with possibly taking the temper out of the edges/thin sections of the inner die faces if I don't religiously let it air-cool between every part or two. What alloys sound like a good fit for the above? My priorities are hammer-struck forging die-calibre toughness + hardness, decent machinability for filework, ease of tempering, and a degree of hot-hardness. The H-series steels are the go-to for hot tooling, but their heat treatment schedules are a problem for me as they all call for a multi-hour soak at high temperatures. That's the case for all air-hardening alloys, probably, although I've never attempted to heat-treat sth common like A2. Some of the M-series high speed steels with high toughness + red-hardness seem like a good fit, and they'd probably come pre-hardened, but I'm dubious that the temper of a cutting tool blank will be suited to a forging die. And then there's old reliable, our good friend O1, which i'm quite comfortable forming and tempering with my current workshop, but which I've never attempted to use in a hot-forging role before. i suspect hot-hardness is what I can compromise most on, given the limited thermal energy in a 1/8" bar + the fact that I can just work slower to let the heat dissipate a bit, so my inclination is to just try making a trial die using whatever tool steel flat bar i have on hand and hope it holds up for at least a couple hundred strikes Ambrose Burnside fucked around with this message at 19:31 on Jan 6, 2021 |
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Jan 6, 2021 17:49
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Sooo another thing I've been loving around with at the new job is manual lathe work. Never really did much of it at all where I was previously. Have a question on best tool lead angles. We've got a large supply of basic TPG triangle carbide inserts, so that's what I'm using. The tool holder it goes in naturally holds it at a 0 degree lead angle, but I can rotate the holder to get whatever angle I want out of it. I've been doing something like a +15 degree lead angle for most of the roughing stuff I've been doing, just wondering if it's ideal. I generally have to take some pretty heavy cuts on what is usually big chunks of 420ss. Been thinking about trying to increase that lead angle, just not sure how well it would work.
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Jan 10, 2021 19:56
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Do you have some scrap stock? Just try it and see what happens
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Jan 10, 2021 20:07
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Yeah, it's probably worth your time to do some experiments and generally push the tooling a bit, especially if you have lots of those particular inserts on hand. Accept that you're gonna ruin one or two and play with variables until you have a sense of where the sweet spot is for throughput, how to get a good finish without spending a lot of extra time/effort, and what sorts of feed rates you can manage until the insert gives up the ghost. i know with manual turning specifically I like to test a new tool to the point of burning and/or failure just once if I possibly can, because without having that reference point I tend to either work conservatively and waste time + not use the tool to its fullest capability, or else I fly blind until I break a tool when it really matters and i'm in a crunch. lead angle is less of a "until failure" sort of thing, instead you'll learn where the tool stops functioning acceptably. more generally: with sth like production work i'm not experienced with, I have found it very much worth my time to produce a well-documented tester bar. get a decently-long section of stock, chuck it up well using the tailstock if possible, do your facing pass to get the bar nice and true for your setup, the usual if you're being precise. i pick my variable to test, usually feed/speeds or DOC but tool angle in your case, and then pick a half-dozen to a dozen different values, then divide the test stock into the required number of similar segments an inch or two long, visually w/ scribe-marks is fine but physically with a cutoff tool is better (slightly deeper slots than the intended test-cut DOC) b/c it frees you from having to plunge in to start the cut or possibly from even having to touch the x-axis at all until you're done. for documentation purposes i like to scale the test bar divisions down to fit on the long side of a gridded shop pad so i can reproduce the tested variables to conform to the actual piece of stock. then you lock in all the variables you're not testing- writing them down or the whole thing is moot if you forget- and do a test cut across each segment, finishing the bar without changing your setup or workholding more than is strictly necessary. if you're lucky you learn something and end up with a physical reference for the future; if you're unlucky it all looks equally-lovely and you need to try another variable / expand the range you tested. with this system i'll try to run a couple tester bars, each exploring a variable i'm not confident with, and each tester gets its own labelled row on the gridded sheet; eventually that sheet becomes a "master legend" for the tester bars, which ideally get put in a labelled bin in the crib or your toolchest, lest someone decides your unlabelled tester bars ought to go in the scrap bin this process seems extremely neurotic compared to other people's methods, but I like it for its long-term usefulness; once you move on to another contract/task a lot of the finer points you've learned tend to fall out of your head, this saves me from having to re-learn stuff and make those little Learning gently caress-ups multiple times just b/c i havent had to do aggressive cuts on a tool alloy in 6 months or what-have-you Ambrose Burnside fucked around with this message at 23:24 on Jan 12, 2021 |
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Jan 12, 2021 22:55
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crossposting this from 3d printing thread b/c it tidily straddles both topics: Ambrose Burnside posted:does anybody here have any information/experience with electroplating onto prints, more specifically electroforming copper for mechanical instead of aesthetic purposes? I've been reading a lot of academic/research literature about rapid prototyping/rapid tooling processes that integrate SLA printing, and something that keeps coming up is electroplating a thick shell of copper or nickel over prints to produce functional composite parts. It makes them dramatically stronger (to the tune of, for example, iirc 5-10x better shear strength depending on material and plating thickness), reduces part-on-part friction significantly so close-fitting assemblies are more viable, it eliminates creep over time, and it prevents UV degradation of the resin underneath. It seems to address essentially all of the downsides of SLA parts, and makes them more suitable for use in mechanically-demanding applications. I remember posting some big infoposts about it months ago when I first ran into it and it put hooks in my brain.
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Jan 15, 2021 21:02
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Ambrose Burnside posted:crossposting this from 3d printing thread b/c it tidily straddles both topics: I have done the opposite and used a 3d printed part as a way to mask off a certain area from being electroplated. It worked well and we now use it for prototype stuffs. The process we do won't go onto anything except metals. Please post your results, I'd be curious to see how it turns out.
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Jan 15, 2021 21:39
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I just got a $200 tig welder off ebay! I have no experience tig welding! Anyone got any good resources for absolute beginner tig welding? I've done a small amount of mig, stick, and gas welding, but no tig. I haven't bought a gas cylinder for it yet and probably won't get to it today so I'm watching some youtube vids and planning on setting it up next week.
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Jan 15, 2021 22:05
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Yooper posted:I have done the opposite and used a 3d printed part as a way to mask off a certain area from being electroplated. It worked well and we now use it for prototype stuffs. The process we do won't go onto anything except metals. Please post your results, I'd be curious to see how it turns out. Neat. What sort of stuff do you do, do you mind me asking? MEMS or sth in that neighbourhood? I actually plan on taking two complementary tacks w electroforming: encapsulating resin parts to make functional composites as described, but also as a way of making durable, hard-wearing and highly-detailed metalworking dies without any use of machine tools. the second was originally my main interest wrt 3d printing, as a means to cheaply producing my own detailed 3d dies for stamping metal parts cheaply and quickly using a hydraulic press; i don't really want to do "normal" 3d printing things with this, I see it mostly as a way to produce detailed masters as a part of other workflows. anyways, the tooling workflow: you paint the part w conductive paint on the "tool face" part of the model, plate a thick layer of metal, free the model from the shell (either gently prying it off or using a jeweller's wax resin and burning it out), and then backfill the shell cavity with an incompressible mineral-filled tooling resin that can take the compressive strain from a press. The copper acts as a harder-wearing face for the tool and preserves the tiniest details from the master, and the tooling resin stops the shell from collapsing/deforming under pressure. it's an established if obscure workflow for rapid tooling in industry, but all the resources I can find are from before the consumer SLA printer revolution, I'm not sure if any hobbyists have revisited this stuff since the master modelling step, normally the hardest and most labourious/time-intensive part of any tool-making process, is now trivial to hand off to an entry-level SLA machine. here's a quick overview of the process;  only big difference is i plan on using conductive paint to make the model platable instead of using metal spraying. The latter would be preferable but access to the equipment is a hurdle i dont wanna deal with these next few images are from an industry report on accessible diemaking techniques for metalworkers; the first chart has their established workflows, with my own added to the right  and here's their documentation of electroforming as used in their own workflow, instead of the copper being used directly as the tooling face it is instead used to make a very high-fidelity, durable master from a carved wax original; in all cases they use a lathe replicator probe to directly reproduce the master in steel, which becomes the actual tool. electroformed shell+resin-filled composite tools are not regarded as being as durable or long-lasting as a proper tempered steel tool, but I can still expect to get hundreds or thousands of parts before excessive wear becomes an issue, which is more than fine for my small-run purposes.   
Ambrose Burnside fucked around with this message at 01:01 on Jan 16, 2021 |
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Jan 15, 2021 22:13
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Vim Fuego posted:I just got a $200 tig welder off ebay! I have no experience tig welding! Anyone got any good resources for absolute beginner tig welding? I've done a small amount of mig, stick, and gas welding, but no tig. I haven't bought a gas cylinder for it yet and probably won't get to it today so I'm watching some youtube vids and planning on setting it up next week. Noice. The weld.com videos were pretty useful for me. Ones like this: https://www.youtube.com/watch?v=KFzhW3KpHpk Also, the various "Mr Tig" stuff like this: https://www.youtube.com/watch?v=ZWJt3fFJ6Hk Start jumping down that rabbit hole while you wait for it to show up.
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Jan 15, 2021 22:33
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Motronic posted:Noice. The weld.com videos were pretty useful for me. Ones like this: Cool. I've seen videos from weld.com before, Mr Tig is new. I'll check 'em out
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Jan 15, 2021 22:39
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Check out some of the older This Old Tony videos as well.
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Jan 15, 2021 23:48
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had a brainwave irt electroformed tooling: instead of trying to remove a resin master model w/o destroying the shell or dealing with expensive and inconvenient-to-burnout printable waxes, use sth like woods metal. rather than printing a 1:1 master model, print the negative of it, and then cast the fusible alloy into that to get your positive master. it's uniformly conductive so i can omit the conductive-surface-treatment step, and once the forming is complete i can melt out the mandrel with a torch or electric solder pot or sth like that. much cleaner and simpler than a wax burnout. i checked out rotometals for a cadmium-free alternative to wood's metal, and not only is there a preferred alloy for making electroforming mandrels with, there's another, much more rigid/creep-resistant low-melt alloy that's ideal for metal-forming tooling, suitable to the low tonnages I'd be working with. so i think i can totally skate on having to work with tooling epoxies for backfilling, and as a bonus the fusible alloys are infinitely reusable, so if a tool wears out or breaks you recover the alloy and use it to backfill a replacement/new die. The fusible tool would probably be less durable than the tooling epoxy, but the datasheet says I can safely apply 8 tons per square inch of alloy for 30 seconds without permanently deforming the die, and most dies would be bigger than that, so it should work as a long-term backfill material without excessive creep setting in after a couple of parts, which is what happens with typical lead-based dies under 'slow' pressure (weirdly enough it makes great drop-forging dies). also-tool costs drop to nothing if I can recover the backfill material so who cares just make another. or test designs w fusible alloy, empty them and backfill w epoxy if I get a real winner that I'm gonna use for production. i got options. maybe even skipping electroforming for low-detail/soft embossed designs and directly producing remeltable stamping dies from resin-printed negative masters, i dunno. i'm hyyyype this is a much more elegant and economical way to do this (note to self: Roto281-338F for electroforming mandrels, Roto217-440F for backfill) also i did some research looking specifically for fusible alloys in rapid tooling workflows and ofc dentists have been using wood's metal for decades to support electroformed crowns during fabrication, i actually found a really nice small-scale workflow from an article written in 1945. and it contains this frankly phenomenal hot tip, i wish more technical journals recommended molasses for unusual applications Ambrose Burnside fucked around with this message at 03:10 on Jan 16, 2021 |
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Jan 16, 2021 02:25
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Anyone want to recommend a lathe? I don’t really have a budget but maybe let’s say $1k plus or minus? It’s flexible. I don’t have a specific need in mind, I just like to make poo poo and would really like to add “round metal objects” to my repertoire in a way that goes significantly beyond that partially-brass tap handle I posted earlier. So I’m just a hobbyist, but I also don’t want to grow out of whatever one I get after the first month. If not a specific item, brand recommendations I should look at are also appreciated.
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Jan 17, 2021 04:26
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Bad Munki posted:Anyone want to recommend a lathe? I don’t really have a budget but maybe let’s say $1k plus or minus? It’s flexible. For general-purpose turning the go-to starting machine is an import 7x14 or 7x16 lathe, i don’t know if you can do any better quality wise than buying one at harbour freight but it’s prolly gonna be the cheapest source. Littlemachineshop, who i like dealing with, has seig 7x14s for $750 although they don’t have stock rn. that said, I would budget almost that much just for tooling and fixtures, but you can save a lot on the fundamentals by grinding your own HSS tools as you’re starting out (which i highly recommend, it teaches you what makes for a good tool and how to repair/regrind stuff that chips), stuff like that. Alternately buying up someone’s Aborted Turning Setup is a fantastic way to get a great deal on barely-used accessories.
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Jan 17, 2021 05:56
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