|
unrelated, but of General Interest: dear metalthread friends, there is apparently a small but non-zero possibility of the forums exploding in the near future, there's a DIY discord that's set up to give everybody an alternate place to chat. https://discord.gg/UuS3ehc copy the link down somewhere, get verified in the stickied thread up top, just in case b/c it'd be a shame to lose two-thirds of the posters in here to a Sudden Suspension of Posting Services
|
#
?
Jun 24, 2020 22:08
|
|
|
|
| # ? May 25, 2024 22:33 |
|
|
triple-post combo: ehhh i got time to kill, so aluminium forging 101: the aluminum alloys you'll probably encounter (6061 the most common) are quite soft in the annealed state and are very easy to form and bend while cold, but it work-hardens rapidly as you work it and then becomes brittle/prone to cracking if you push it too far. the key to working aluminium is to not push it too far on a single annealing cycle, because once it fails and cracks the part is typically junked unless you can totally file the affected area out. fortunately aluminium is annealed quickly and easily without a kiln, it behaves like copper/cuprous alloys in that heating to critical temp -> quickly quenching softens it, while heating to critical -> slowly cooling tempers (hardens) it. the main tricky part here is that aluminium melts before it glows and does not change magnetic states at the critical temp like steel does, so it can be easy to overheat and melt an aluminium part. the secret to this is using a temperature indicator that visually changes when a given critical temp is passed. templstiks are the "pro" product for this, but you'll probably have to special-order them. lucky for us, there's another household product that just happens to change colours slightly above aluminium's critical temperature- white soap. Just plain-jane Ivory soap, the cheapest you can get. Rub the bar on the metal across the entire area to be annealed, a stripe down a bar of metal or a spiral mark if it's sheet. Play a torch across the opposite, non-marked side of the metal so you're not directly heating the soap; use a bushy, soft flame with a fuel that offers a cooler, mushier flame envelope, propane or natural gas is good for this while acetylene or MAPP isn't. aluminium is a great heat conductor so the whole piece should come to temp fairly evenly. Once the soap has charred to black, immediately quench the entire piece into water and move it around continually to stop steam bubbles from insulating parts of the metal and causing uneven annealing. quenching is actually sort of optional but i highly recommend it, it will end up noticeably-softer than if you air-cool it, and will let you work for longer before having to anneal again. i always annealed anything small enough to fit in my quench tub. for annealing round rod that's inconveniently long you can use a water-filled length of steel pipe with an end cap as a "tub" if you don't have a metal tub/bucket at hand. be very careful using plastic rubbermaid bins or w/e for quenching because the stock will melt a hole through the sides/bottom if you let them touch. that said, I've absolutely done a ton of quenching in an old plastic pretzel tub, so I wouldn't spend any money for this part if you're just making a handful of parts here. Follow the above and you'll never destroy an aluminium workpiece from overheating; i've made prolly 100+ forged and hot-annealed aluminium parts over the years and all of my failures were from greedily hammering hardened metal past a sensible threshold, never from overheating. Once it's annealed you can usually get a fair bit of work done before you need to anneal again, but because it's a quench anneal it's very quick and doesn't really slow your work down much. Try hammering some scrap bar to the point of failure, just to learn how the metal changes as it work-hardens and to learn the warning signs that you're pushing the metal too far, then experiment with annealing on more scrap to see how far you can push it before you work on yhe actual part. Aluminium can also be hot-forged like steel is, albeit at lower temperatures, but if you're doing this you might as well just make the thing from steel. It also sucks to hot-forge because it's such a wicked heat conductor, you can't hold onto a long piece of stock in the forge without it burning your hand very quickly, the excess stock will sap all the heat out of the work zone and generally make your life difficult. That said, I wouldn't rule it out for the most extreme forming processes, like for shouldering the stock to make the holdfast-work contact point. that's a ~50%+ thickness reduction and should be formed in as few blows as possible, doing that sort of forming cleanly on cold stock is very difficult. instead of a clean shoulder, established with a very hard initial blow on hot metal that moves a lot of metal all at once and cleanly defines the shoulder geometry, you'll get a "staircase" of 20 small, continually-jumping-around shouldering blows that make for an uncontrolled ramp instead of a sharp vertical edge. .,,then again, you may not need a hard shoulder on the dog "working face" at all, if you're trying to catch the 90-degree corner of a workpiece with it you will but if it's applying vertical force to a flat face you probably don't. I've only made a few of these and they were for holding metal to an anvil, not wood to a bench, and had a smooth n flat working face that wouldn't have needed that shoulder. in any case, the takeaway is- think about the exact use requirements for your specific tool and plan the forming operations ahead of time to guarantee good controlled results, it's very easy to panic as the work veers away from your preconceived design and end up just kind of hammering things around arbitrarily, hoping stuff comes together. it's a good workout but not a good way to make tools. Ambrose Burnside fucked around with this message at 22:57 on Jun 24, 2020 |
|
#
?
Jun 24, 2020 22:25
|
|
|
One of my life goals is to have never used Discord. If this forum goes bye bye, then bye bye in advance to all of you.
|
|
#
?
Jun 25, 2020 06:04
|
|
|
Mirconium posted:General question on lathes: the answer is heavily, "it depends" A southbend headstock for a 9" from 1899 may fit on the bed of one ground in 1920 (back before the 2nd world war lathe castings were often aged in the field for up to a decade because metallurgy was so bad -- i have a southbend 9" that was sold to GE in 1912 but cast around 1890 according to the file card I got from the last guy at LeBlond) the problem is a lot of these parts were mass manufactured but modified to fit the parts they were built for. Some parts may have worn into the system they were built for. So you may get something nominally from another machine and try and fit it to something else and have a very sloppy fit. As you get past WW2 machines this becomes less of a concern, but you may still have to shim things to get it back to alignment. This is all to say, if you have a pile of Southbend heavy 10 parts, you can probably make a lathe, but expect to gently caress with everything as they weren't really that precise of a machine. In any case, buying random parts off of ebay these days is something of a fools game to try and produce a functioning lathe, much less repair an existing one without the original part numbers and part books from the time. Obviously none of this applies to anything post late 70s as NC/CNC machining took most of the problems out of "machines built on a day ending in Y" Also if this forum goes away I hope you folks keep up in discord or whatever poo poo forum we end up on.
|
|
#
?
Jun 25, 2020 10:49
|
|
|
Join the boomer community on practical machinist
|
|
#
?
Jun 25, 2020 11:03
|
|
|
His Divine Shadow posted:Join the boomer community on practical machinist A fate worse than death.
|
|
#
?
Jun 25, 2020 11:29
|
|
|
His Divine Shadow posted:One of my life goals is to have never used Discord. If this forum goes bye bye, then bye bye in advance to all of you. The breadnroses.net forum seems to be the most likely lifeboat-made-from-the-sinking-ship at present, though I've not yet joined so can't vouch.
|
|
#
?
Jun 25, 2020 11:40
|
|
|
Yooper posted:A fate worse than death. Truer words never spoken.
|
|
#
?
Jun 25, 2020 11:41
|
|
|
There is now a metalworking thread to lord your supremacy over wood working "normies".
|
|
#
?
Jun 25, 2020 11:48
|
|
|
sharkytm posted:Truer words never spoken. I'd rather bury my Mitutoyo micrometer, snap my Interapid indicators, and salt the earth with my case hardening jar than become an active member of Practical Machinist. Pimblor posted:There is now a metalworking thread to lord your supremacy over wood working "normies". Is this at breadnroses or ? I've seen people mention it before but I have no idea what it was.
|
|
#
?
Jun 25, 2020 12:59
|
|
|
His Divine Shadow posted:One of my life goals is to have never used Discord. If this forum goes bye bye, then bye bye in advance to all of you. nobody wants to *end up* on discord, i can’t imagine goons settling for anything other than a classically-structured forum environment, it’s more so that there’s a rendezvous point for posters if tomorrow we log in to find a THANKS FOR THE MEMORIES page replacing the forums or sth like that. so people don’t get left behind and have no way of finding where everybody’s gone off to, that sort of thing
|
|
#
?
Jun 25, 2020 14:46
|
|
|
Yooper posted:Just make sure you don't get some weirdo impossible to find taper or mounting arrangement on some crazy old lathe from Yugoslavia. As the resident  lurker:(a) how dare you (b) fuckin' Croats, probably
|
|
#
?
Jun 25, 2020 16:52
|
|
|
Yooper posted:I'd rather bury my Mitutoyo micrometer, snap my Interapid indicators, and salt the earth with my case hardening jar than become an active member of Practical Machinist. https://forums.somethingawful.com/showthread.php?threadid=3929094
|
|
#
?
Jun 25, 2020 16:59
|
|
|
His Divine Shadow posted:One of my life goals is to have never used Discord. If this forum goes bye bye, then bye bye in advance to all of you. It's not that bad, it's no slack but you can turn down most of the worst parts about it.
|
|
#
?
Jun 25, 2020 17:01
|
|
|
cakesmith handyman posted:The breadnroses.net forum seems to be the most likely lifeboat-made-from-the-sinking-ship at present, though I've not yet joined so can't vouch. There's a maker/diy forum there, it's a subforum of arts forum there but I want to get it moved to top level since the diy forum here really benefits from not being the grumpy white man central that many similar forums and I think it could be a big draw. Bnr is explicitly super leftist but obviously that's probably beneficial to maintaining an inclusive and not horrible old douche culture
|
|
#
?
Jun 25, 2020 20:08
|
|
|
Pimblor posted:In any case, buying random parts off of ebay these days is something of a fools game to try and produce a functioning lathe, much less repair an existing one without the original part numbers and part books from the time. Makes sense, for what I want to mess around with a tiny lathe is more than sufficient anyway, so south bend was probably overkill. Ended up snatching up a mostly complete unimat. The asinine moving headstock design seems like kind of a bummer, but the price was right so hopefully it all works out. Thanks for responses! Edit: uhh by the way should I be concerned about lead based paint with these? DearSirXNORMadam fucked around with this message at 20:49 on Jun 25, 2020 |
|
#
?
Jun 25, 2020 20:10
|
|
|
shovelbum posted:There's a maker/diy forum there, it's a subforum of arts forum there but I want to get it moved to top level since the diy forum here really benefits from not being the grumpy white man central that many similar forums and I think it could be a big draw. Bnr is explicitly super leftist but obviously that's probably beneficial to maintaining an inclusive and not horrible old douche culture I'm not old and I'm p left but grumpily hobbling around the workshop and complaining about my bum leg are my prime attributes don't take that from me. Same reason we unluckily get forging jobs in the summer and fabrication jobs in the winter when it would actually be nice to sit near a fire, comfort is the enemy. threelemmings fucked around with this message at 21:22 on Jun 25, 2020 |
|
#
?
Jun 25, 2020 21:20
|
|
|
His Divine Shadow posted:One of my life goals is to have never used Discord. If this forum goes bye bye, then bye bye in advance to all of you.
|
|
#
?
Jun 25, 2020 21:42
|
|
|
Mirconium posted:
are you planning to eat the paint?
|
|
#
?
Jun 25, 2020 21:57
|
|
|
I’m rush-building a small propane forge (with which to forge a gift for someone’s birthday this weekend, hence the rush) because i discovered a long-lost cache of forge repair supplies i thought were lost forever. i’ve got a coffee can, a bunch of 1” kaowool, and two hard insulating firebricks. i have no refractory cement; i have a pint of knockoff ITC-100 UV coating for the wool, but it’s like 5 years old (albeit unopened) and i’m assuming it’s solidified and useless until i crack the can tomorrow. anyways- it’s looking like i’ll have to run the forge with uncoated wool for the time being, which i’ve never done and which is usually regarded as a no-no because of the respiratory issues loose wool fibres can cause. I’d only need to run it for a couple of hours once while uncoated and I can use respiratory protection so i’m not too worried about that, but I am worried that coating/mortar might not “take” as well to a “post-fired” wool face. anybody use an uncoated kaowool liner for any length of time who can comment? alternately, anybody ever successfully use/revitalize an old tub of UV reflector? (it’s HYB-UV, fwiw) e: one more thought- insulation rigidizers all seem to be silica-based, with other components being the carrier fluid, antifreeze etc. could i use sodium silicate (aka waterglass) as a rigidizer? are commercial rigidizers just gussied-up sodium silicate? e: ok, one more: any tips for cutting hard IFBs? i’m gonna have to split a brick in half lengthwise and chamfer it’s corners to get a thin enough floor slab to work w the coffee can shell, it’s gonna be a huge pain and i really wanna get two halves out of it not “a slab plus a bunch of broken bits”. I’m thinking: an extremely busted hacksaw blade, b/c i suspect this firebrick material is gonna ruin anything used to cut it. Ambrose Burnside fucked around with this message at 00:28 on Jun 26, 2020 |
|
#
?
Jun 25, 2020 23:26
|
|
|
Masonry blade with an angle grinder or a tile saw are about the best options I can think of. The hack saw might work, but it's not something I'd personally want to do. As for the refractory questions I don't have any answers.
|
|
#
?
Jun 26, 2020 06:15
|
|
|
I'm not sure what might best for cutting fire brick, I've always seen them cut by hand with a hacksaw and respirator. I'm told the material can toast a blade depending how it's produced (? Some seem sandier than others) But the ones I've always seen seemed to cut fine that way. Kind of a pain depending on how you want to actually cut the brick, have enough room, etc. I know I've seen people in YouTube just use normal waterglass as a rigidizer, I expect if you pulled a data sheet you'd be right in that it's just waterglass and a volatile-ish carrier though.
|
|
#
?
Jun 26, 2020 08:20
|
|
|
Call for a DIY IK https://forums.somethingawful.com/showthread.php?threadid=3930843
|
|
#
?
Jun 30, 2020 15:55
|
|
|
Ambrose Burnside posted:I’m rush-building a small propane forge (with which to forge a gift for someone’s birthday this weekend, hence the rush) because i discovered a long-lost cache of forge repair supplies i thought were lost forever. i’ve got a coffee can, a bunch of 1” kaowool, and two hard insulating firebricks. i have no refractory cement; i have a pint of knockoff ITC-100 UV coating for the wool, but it’s like 5 years old (albeit unopened) and i’m assuming it’s solidified and useless until i crack the can tomorrow. I have a huge gently caress-off masonry saw at work for cutting concrete samples. You're gonna die from exhaustion before you get through that with a hacksaw. If you're near Portland come by and I'll do it for you this week
|
|
#
?
Jul 1, 2020 03:09
|
|
|
firebricks are "masonry" the same way that marshmallows are "solid sugar" which is to say, you can cut the stuff with a butter knife if you're determined, you'll just make more of a mess. The hacksaw is to do it more neatly.
|
|
#
?
Jul 1, 2020 03:14
|
|
|
yeah, i actually ended up doing the chamfering cuts with a jeweller's saw b/c that thin keen lil blade cut much faster than the hacksaw blade did, and jeweller's sawblades are like $0.05 per blade so who cares if i dull one
|
|
#
?
Jul 1, 2020 03:42
|
|
|
I would pay a little bit of money to watch someone cut a hard firebrick with a butter knife. Now the soft firebrick sure, that you can cut with harsh words.
|
|
#
?
Jul 1, 2020 04:03
|
|
|
This started out as buying a $12 lazy susan bearing so I could manually rotate some pipe to flat joints (hundreds, actually) at work without hating life. Once I got the bearing, I stared at it for a while and realized that I have a ton of stepper motors and little gt2 timing belts, pulleys, 8mm shafts, bearings, etc floating around and I could totally make a positioner. So I did, and things escalated along the way.    I shittily breadboarded the control circuit with a regular arduino (will be using a micro or nano when this is actually finalized) and now that I have it moving, I can say that this will work fine for my upcoming hundreds of welds, but to make this a little more reliable, I'll probably redo the mount and put a nema 34 in there and switch over to a small chain drive instead. There's a little too much bounce in the timing belt to leave it as-is in the long term, and I'd like a little more torque at super low speeds. I might eventually have an issue with the small 8mm shaft in terms of transferring power to the plate through the tiny little shaft flange and two set screws, but there are plenty of ways around that. I'd probably just tig weld a split shaft collar on the bottom of it as a first attempt and I suspect that would be plenty. With a nema 23 it should be fine for now with just a small flat ground on the shaft. Hypnolobster fucked around with this message at 06:26 on Jul 5, 2020 |
|
#
?
Jul 5, 2020 06:23
|
|
|
Hypnolobster posted:This started out as buying a $12 lazy susan bearing so I could manually rotate some pipe to flat joints (hundreds, actually) at work without hating life. Once I got the bearing, I stared at it for a while and realized that I have a ton of stepper motors and little gt2 timing belts, pulleys, 8mm shafts, bearings, etc floating around and I could totally make a positioner. As a heads up welders and motion controllers are not friends for EMI reasons. Give it a try and if it freaks out sometimes be prepared to use twisted shielded pair wire with grounded shields and maybe Mose kind of filtering on the power line. Might also work fine with no issues.
|
|
#
?
Jul 5, 2020 14:01
|
|
|
here’s sth a little different, from electronics thread:Ambrose Burnside posted:so i finished building that fm locating transmitter that called for that obsolete LM3909 i was posting about a page or two back; i ended up building the LM3909-equivalent w discreets, which lets me power the thing with a single 1.5v battery. which i dont have any holders for. so i designed my own breadboard/protoboard-compatible wire AA terminals / a modular ‘0.1in-compatible” battery holder system. and dang these actually work great also working on a button cell version. if you solder em into protoboard you basically turn one side of the board into an integrated battery pack, im kind of surprised i haven’t run into anything like this before b/c it’s a p intuitive and elegant way to integrate a battery compartment compared to a big clunky plastic battery pack with wire leads coming off it that you have to screw to your project wherever it’s the least in the way Ambrose Burnside fucked around with this message at 14:31 on Jul 5, 2020 |
|
#
?
Jul 5, 2020 14:28
|
|
|
CarForumPoster posted:As a heads up welders and motion controllers are not friends for EMI reasons. Give it a try and if it freaks out sometimes be prepared to use twisted shielded pair wire with grounded shields and maybe Mose kind of filtering on the power line. Might also work fine with no issues. Yeah, I'm prepared for needing to move everything into a project box if it comes to that. I've got a lot of cat 5 to use as convenient twisted pair if it comes to that. It would be sort of easy to shield the inside of the box the electronics will be living in too, the more I think of it.
|
|
#
?
Jul 5, 2020 14:28
|
|
|
Hypnolobster posted:This started out as buying a $12 lazy susan bearing so I could manually rotate some pipe to flat joints (hundreds, actually) at work without hating life. Once I got the bearing, I stared at it for a while and realized that I have a ton of stepper motors and little gt2 timing belts, pulleys, 8mm shafts, bearings, etc floating around and I could totally make a positioner. This is really cool man, you'll have to do a short video of it. I'll echo CarForumPoster, we tried to use Arduino's for non-critical industrial monitoring, basically for operator displays and found them to be super flaky. I tried every EMI trick I could think of and never could get over the fact that there's three massive 3 phase rectifiers in the same building. I also tested a pulse feeder for a tig welder and the arduino became very unhappy.
|
|
#
?
Jul 5, 2020 15:55
|
|
|
I'm curious what will happen, for sure. Especially since the entire frame of the thing is grounded (through the welder and mains) and the arduino and stepper driver will be inside what amounts to a grounded metal box.
|
|
#
?
Jul 5, 2020 16:34
|
|
|
IRT the Arduino: I can't strongly recommend any particular alternative microcontroller to the Uno for your exact needs, but I would do some research on non-Arduino offerings before picking a replacement, you can do a lot better than a Nano for just a little bit more money. Look at Sparkfun's dev boards, they've developed a ton of specialized microcontrollers derived from Arduino + other designs in response to customer needs. I don't think there's anything specifically tailored to high-EMI environments, but you can probably meet your other needs better. Just to pick one that looks like it might be a better fit for your application and environment: https://www.sparkfun.com/products/14483 "The SparkFun AST-CAN485 Dev Board is a miniature Arduino in the compact form factor of the Pro Mini. In addition to all the usual features that a mini Arduino has, it possesses an onboard CAN (Control Area Network) and RS485 ports, enabling quick and easy interfacing to a multitude of industrial devices. The CAN485 Dev Board bridges the gap between the maker and industrial spaces!" If nothing else, getting a more modern + beefier microcontroller than an Uno or Nano will help ensure that limited clock speed/flash memory/etc etc doesn't become a bottleneck for you down the road.
|
|
#
?
Jul 5, 2020 17:48
|
|
|
I've got a couple different Feather boards, various cheap ESP32s and a Teensy 4.0 here. At least right now, all it needs to do is send clock/direction to the stepper controller. I think if I wanted to run a LCD or do anything with extra servo triggering (for actually fixturing a mig gun or something) I'd definitely use something else. If there's an advantage on EMI from more robust chips I'll definitely jump to that without a second thought, just to hedge my bets. It does currently make a slightly odd sounding single step exactly every second currently, which could be my lovely code or the cheapass stepper driver. Who knows!
|
|
#
?
Jul 5, 2020 18:15
|
|
|
Oh, sorry, ack  I assumed you didn't know much and were going with an Arduino b/c it's what you'd heard of, shoulda checked the ol post history. You're probably more knowledgeable than me so godspeed.
|
|
#
?
Jul 7, 2020 18:29
|
|
|
 Piping is done for the tuyeres. Gonna feed it with a shop vac and charcoal after I cast/cure the refractory material. I may have gone overboard. just a tad. You could cast a toddler in it.
|
|
#
?
Jul 8, 2020 00:27
|
|
|
Ambrose Burnside posted:Oh, sorry, ack I'm actually a microcontroller/general electronics idiot, I just buy boards out of occasional inspiration and grand ideas. They sort of build up 
|
|
#
?
Jul 8, 2020 02:04
|
|
|
Hypnolobster posted:This started out as buying a $12 lazy susan bearing so I could manually rotate some pipe to flat joints (hundreds, actually) at work without hating life. Once I got the bearing, I stared at it for a while and realized that I have a ton of stepper motors and little gt2 timing belts, pulleys, 8mm shafts, bearings, etc floating around and I could totally make a positioner. I did this at a previous job but the fabrication guys actually wanted something like this to weld on conical reducers into these special gas injectors. The fitter brought in an old flywheel off his Hilux ute and I figured out the dimensions and made a speed controllable and direction controllable thing with a lil gear motor. Worked a treat
|
|
#
?
Jul 8, 2020 05:24
|
|
|
|
| # ? May 25, 2024 22:33 |
|
|
Hi folks! Just got active in a medieval reconstructionist smithy, so I expect to pose a lot of dumb questions in the time to come.
|
|
#
?
Jul 8, 2020 22:49
|
|
