|
kastein posted:Agreed. One wheel is probably more than you'll get out of a couple dozen hard drives. FWIW I would be extremely wary of heating anything magnesium in air, given that once a combustion reaction begins, it can be nearly impossible to put out. It may also provide enough energy to ignite impurities or burn-off gasses in an enclosed furnace. Source: I've seen 10 pounds of magnesium light up like the sun in a fire pit.
|
#
?
Dec 18, 2015 19:14
|
|
|
|
| # ? May 25, 2024 16:48 |
|
|
Agreed. Mag fires are drat near impossible to put out, and the extreme amounts of UV emitted by the fire can permanently damage your eyes and give you a hell of a sunburn.
|
|
#
?
Dec 18, 2015 19:47
|
|
|
Fun fact: before TIG welding existed, all magnesium was welded with oxy-acetylene torches. GTAW was actually invented specifically for welding magnesium with a minimum of frustration and also disastrous fires
|
|
#
?
Dec 19, 2015 00:52
|
|
|
I'm brainstorming the design of a sheet metal enclosure. Do all bends have to be parallel to the edges? I understand that there are repositionable guides that the operator pushes the edge of a sheet against to get the correct distance from the edge to the bend. Would it be difficult/expensive to fabricate a part that have bends that are at an angle to the edge?  (just a rough illustration of what I mean - I'm aware there might not be enough clearance to bend this anyway) rawrr fucked around with this message at 02:48 on Dec 19, 2015 |
|
#
?
Dec 19, 2015 02:46
|
|
|
Bends can be anywhere but it will increase cost when you don't use standard angles. I think your sketch has a trouble spot where the two bends almost make a point to the right. There may not be enough room for the tooling but check with your vendor. I think they'd work from the crown outwards. There's a How it's Made that shows how they make the tapered octogon telephone/utility poles. They cut a notch in the flat profile to line up the bends with the bender. Also they had huge galvanizing tanks that were very cool.
|
|
#
?
Dec 19, 2015 03:25
|
|
|
rawrr posted:I'm brainstorming the design of a sheet metal enclosure. Do all bends have to be parallel to the edges? I understand that there are repositionable guides that the operator pushes the edge of a sheet against to get the correct distance from the edge to the bend. Would it be difficult/expensive to fabricate a part that have bends that are at an angle to the edge? Don't make it out of Al-7075 by the way. I learned that the hard way this week.
|
|
#
?
Dec 19, 2015 03:54
|
|
|
rawrr posted:I'm brainstorming the design of a sheet metal enclosure. Do all bends have to be parallel to the edges? I understand that there are repositionable guides that the operator pushes the edge of a sheet against to get the correct distance from the edge to the bend. Would it be difficult/expensive to fabricate a part that have bends that are at an angle to the edge? No, bends do not have to be parallel to the edges. That point where the bends meet actually looks pretty doable to me (e: in common grades of carbon and stainless steel, not aluminum). If clearance is an issue (and it looks like it would be), then you can just cut two identical halves and form them in opposite directions before butt welding them down the center. If you're using a CAD program to create a flat pattern for a CNC cutter, you might dimension the ends of the bends from corners of the flat pattern on a separate drawing. Also, using Pronest + AutoCAD, you can even make Pronest interpret a certain layer in AutoCAD as a "punch point," which means that the laser/plasma cutter will just make a little burn mark at the center of a circle of that layer. If you put two of those "punch point layer" circles at either end of your bends a short distance from the flat pattern edge, it takes all the guesswork out of laying out the bends (you just chalk line between pairs of burn marks). That's the limit of my experience, but I imagine other software packages have similar features. Eugene V. Dubstep fucked around with this message at 05:22 on Dec 19, 2015 |
|
#
?
Dec 19, 2015 05:13
|
|
|
If you need small quantities of those things and the (nonferrous, annealed) metal is reasonably thin (>16 gauge) I'd just cut the flat blanks and score the fold-lines with hard wire taped to the metal in position and hammered into it with a planishing hammer. You can wizard up just about any folded form that way, even some really weird geometries you could never do with any other technique.    It's clearly an artistically-oriented technique but I've used straight wire scoring in lieu of a press brake to fabricate small boxes and the like pretty accurately. You can also score with a cutting tool or by planishing on the crisp edge of an anvil, but wire scoring is the only score-folding technique that produces bends just as strong as the original metal.
|
|
#
?
Dec 19, 2015 07:24
|
|
|
Ambrose Burnside posted:If you need small quantities of those things and the (nonferrous, annealed) metal is reasonably thin (>16 gauge) I'd just cut the flat blanks and score the fold-lines with hard wire taped to the metal in position and hammered into it with a planishing hammer. You can wizard up just about any folded form that way, even some really weird geometries you could never do with any other technique. Oh wow, that's pretty.
|
|
#
?
Dec 19, 2015 08:53
|
|
|
Holy poo poo, that's a fantastic solution.
|
|
#
?
Dec 19, 2015 10:30
|
|
|
To be clear, it's a very slow way to do things compared to an actual press brake and accuracy/consistency will be lower (especially the bend angles, you can't "play with" the folds much because the scores are so work-hardened they will crack very quickly) and you definitely can't do it on very thick or hard sheet, but I see it addressing your "no clearance on weird bend geometries"/"cost is a big consideration" concerns pretty tidily.
|
|
#
?
Dec 19, 2015 16:46
|
|
|
rawrr posted:I'm brainstorming the design of a sheet metal enclosure. Do all bends have to be parallel to the edges? I understand that there are repositionable guides that the operator pushes the edge of a sheet against to get the correct distance from the edge to the bend. Would it be difficult/expensive to fabricate a part that have bends that are at an angle to the edge? This is literally what I do for a living :] First of all, sheet metal brake bends are almost never parallel to the edge of a sheet unless you're making a box. This is the flat pattern for an offset square-to-round transition, which is very similar in principle to what you've drawn (a half pattern of one, anyway)  How thick is the material? Are there specific shapes you're trying to match at each end? If it's thin enough to be made in a hand brake, it's all done by eye and back gauges are a nuisance unless tolerances are very tight. The operator will likely just draw lines or mark points at the end of each brake line and do it by eye, even in a hydraulic brake. The thing about sheet metal is it's hell of malleable. These days I build electronics enclosures for a living, and even with a computer aided back gauge and tolerances of +- 0.010", if you're a little tight or loose somewhere a wooden mallet strike just so can solve just about anything. If you are making this out of 1/4" plate with tolerances that are very frustratingly close, you'll have to spend the money for a CNC brake with independently adjustable backgauges, or a lot of a tradesperson's time. Though I'm willing to bet this is not the case. The hardest part of sheet metal work is always the pattern development, and, well, you're cheating and using a computer so the hard bit's done already.
|
|
#
?
Dec 19, 2015 16:55
|
|
|
Mr. Bill posted:This is literally what I do for a living :] This is literally what I do for a living. I work for a metal stamping company. We make stuff stamped and laser cut from all kinds of things, from .010" thick all the way up to 1/2" thick. Order volumes from 100s to 100,000s. We use punch presses, brake presses, and progressive presses for all of our stuff. rawrr posted:I'm brainstorming the design of a sheet metal enclosure. Do all bends have to be parallel to the edges? I understand that there are repositionable guides that the operator pushes the edge of a sheet against to get the correct distance from the edge to the bend. Would it be difficult/expensive to fabricate a part that have bends that are at an angle to the edge? When I saw that picture, I said "that's two two-hit V-forms in the brake press and a U-form in the punch press." We could probably hold .030" tolerance without any major problems, depending on thickness. Mind you, we don't do a bunch of stuff in "sheet" like ductwork thin (22ga/.030); almost all of our multi-step processes are 6-12ga(.100-.200).
|
|
#
?
Dec 19, 2015 19:13
|
|
|
Alright! I survived my first day of melting metal. Did a bunch of cans just to practice getting the dross out and pouring. That went well so I did a second run and melted a handful of those hard drive bottoms. Didn't find any of the magnesium ones (thanks for the heads up there) but my "safe" solution was to toss in a ~dime size piece of each one as a test. If it lights up like the giant sparkler I'll know it's a no go for that one. This doubles as destroying these things, as a lot of them potentially contain bank data/other crap and it's a lot more useful than dulling bits in my drill press to destroy them. Did note a couple problems on the day. The crucible was very hot at the bottom but the heat was very uneven at the top, so every time I skimmed dross I was taking good bit of aluminum with it. This was likely due to the fact that the lid isn't really the best size, so I was losing heat out the top. My muffin tin also fell apart after the pour, as I was trying to tap out the ingots. Oh well on that second one, but I think I'll look into using some cast iron pans I don't use/need anymore. All in all just minor things. It's obvious this refractory recipe is complete crap and won't survive another 3-4 burns. The lid letting out heat is really annoying too. Still, it was worth it, imho, because I can find a use for the rest of the plaster and it gave me some needed practice and knowlege in building and pouring but I'm going to outgrow this thing almost immediately. And on that vein here's my current next plan, can someone with more experience please double check my work to make sure I'm not misinformed/about to do something expensive and stupid? Cheap and stupid is one thing but $50 is kind of my stupid limit here. I dumpster dove for a smoker awhile back that just had some surface rust. A little high temp spray paint and it was good but I don't really use it since my grill has a side box. Measures 19" high, 17" wide without the lid. I'll line the inside, including the bottom, with 1" of ceramic fiber insulation rated to 2600*F. After that, I've found some Refecrete KS-4 PLUS Castable Refractory locally and will pour a 2" lining with that as well as make a lid out of the refractory using similar methods to that youtube I previously posted. After that, drill the hole for the air input pipe and I should be done. That should give me a new inside diameter of 11", which should be big enough for anything up to a nice K size crucible. If I have any supplies left over I'll make another smaller bucket one. I got a spare bucket the same size laying around or I might just scrape out the crumbling "refractory" out of the current one. Anything wrong with this plan outside of maybe needing to hide the receipts from the wife? I appreciate all the help and input I've gotten from you guys so far. Anubis fucked around with this message at 07:24 on Dec 20, 2015 |
|
#
?
Dec 20, 2015 06:34
|
|
|
Thanks for all the tips and advice guys (for my sheet metal enclosure) - the amount and variety of knowledge and expertise in this thread is astounding.
|
|
#
?
Dec 20, 2015 19:06
|
|
|
This is neat, internal machining on cutaway cylinders filmed with strobed lighting. https://www.youtube.com/watch?v=78XYpr2Vnvg https://www.youtube.com/watch?v=78XYpr2Vnvg
|
|
#
?
Dec 20, 2015 22:13
|
|
|
Ambrose Burnside posted:all magnesium was welded with oxy-acetylene torches. That is a very concerning juxtaposition of words  It'd probably convince me to work on inventing a new welding process, too. Holy poo poo.
|
|
#
?
Dec 21, 2015 17:29
|
|
|
Took marginally better shackle pictures. 
|
|
#
?
Dec 21, 2015 21:31
|
|
|
echomadman posted:This is neat, internal machining on cutaway cylinders filmed with strobed lighting. haha I'm using those PH Horn superminis at work right now, pretty sure they only cut half a part not to reveal the action but to conceal the godawful nightmare chip control
|
|
#
?
Dec 22, 2015 01:36
|
|
|
shame on an IGA posted:haha I'm using those PH Horn superminis at work right now, pretty sure they only cut half a part not to reveal the action but to conceal the godawful nightmare chip control I was wondering how to deal with chips on a real part. Coolant/lube flood?
|
|
#
?
Dec 24, 2015 03:14
|
|
|
Small cuts and lots of retracts to clear chips. With tiny tools, especially grooving tools, there's no room for the chips to get past the tool.
|
|
#
?
Dec 24, 2015 06:59
|
|
|
Did you give any metalwork as a gift? I spend a lot of time in my forge just 'practicing,' making pieces that will never be seen by other people. Fun, but not ultimately very satisfying. For Christmas, I wanted to give something that was 100% completed and nice. I got 99% of the way there!  I had to file one of the brass rivets down, and that removed the finish. Otherwise, I'm pretty happy with these.
|
|
#
?
Dec 29, 2015 14:18
|
|
|
babyeatingpsychopath posted:I was wondering how to deal with chips on a real part. Coolant/lube flood? Yeah we've got through tool coolant on everything and it helps with flushing them out of the bore but once one gets wrapped around the bar, birdnesting is inevitable. I usually have to stop and manually remove them every 10-20 minutes. Where it gets really crazy is our coolant pressure runs over 15 bars and at least once a day enough stringy chips will thread-the-needle to block the coolant nozzles from the inside. E: Really, that's the million dollar question on high-volume jobs. This is an industrial situation where we've been running the same part 24\7 for two years and there's still more refinements to the process every week and almost every problem whether part quality or machine downtime is caused by chips. The next experiment will be scrapping the boring process entirely and trying custom made carbide step reamers. shame on an IGA fucked around with this message at 20:05 on Dec 29, 2015 |
|
#
?
Dec 29, 2015 19:50
|
|
|
Through tool coolant *drool*
|
|
#
?
Dec 29, 2015 22:20
|
|
|
I swear Amazon knows I have gift card credit, because the prices of all the tools I want to buy with it seem to be roughly 3-5x what they usually are. A height gauge accurate to .001 should not be $400. A set of 3 tail pipe expanders also shouldn't be $250, if individually, they are $15-30 each. That being said, I have some credit on amazon.ca and want to get a metalworking tool of some sort. I have been looking at getting telescoping gauges, or a height gauge or a set of stub length drills to start. The Canadian Amazon has far fewer tool options than the US site, and credit isn't transferable between .ca and .com. Maybe a handheld bandsaw even.
|
|
#
?
Dec 30, 2015 20:09
|
|
|
Brekelefuw posted:I swear Amazon knows I have gift card credit, because the prices of all the tools I want to buy with it seem to be roughly 3-5x what they usually are. Welcome to Canada, our prices on serious tools for machinists and the like are horrendous. Also, I'd advise the telescoping gauges, not a height gauge. Unless you've got a proper table, the height gauge isn't going to be 100% on.
|
|
#
?
Dec 30, 2015 22:22
|
|
|
MohawkSatan posted:Welcome to Canada, our prices on serious tools for machinists and the like are horrendous. Also, I'd advise the telescoping gauges, not a height gauge. Unless you've got a proper table, the height gauge isn't going to be 100% on. I have a few granite flats at work. Leveling a trombone handslide to be dead parallel along the length of it requires a good stone. Telescoping gauges I need more than a height gauge, but there ave been a few times lately where one would really be useful for layout and alignment.
|
|
#
?
Dec 31, 2015 02:06
|
|
|
Happy new year folks. I spent five minutes trying to write some poignant little poem to cap the year, but I couldn't really come up with anything satisfactory. So I guess pretend I came up to you at a party, handed you a drink, honked your tits or butt and ran off hooting like Daffy duck.
|
|
#
?
Dec 31, 2015 20:23
|
|
|
Blacksmith question - how do you estimate how much longer a piece will be, once it's drawn out? I'm practicing with handles for furniture, and once I do some tapers, it seems completely unpredictable how long the final piece will be. Is there a rule of thumb or trick? Same with doing scrolls; how do I know how much of my piece it's going to take to do a scrolled end? Is it just experience and practice, or are there guidelines?
|
|
#
?
Dec 31, 2015 21:13
|
|
|
Pagan posted:Blacksmith question - how do you estimate how much longer a piece will be, once it's drawn out? I'm practicing with handles for furniture, and once I do some tapers, it seems completely unpredictable how long the final piece will be. Is there a rule of thumb or trick? In the past, I've used a piece of copper wire bent into the rough shape of my scroll to estimate length, but I am lazy and just cut the piece long, hammer out what I need, then trim to length. You could easily take a piece, measure it first, then make your scroll or taper and measure it again to see how much you used for the taper or scroll.
|
|
#
?
Dec 31, 2015 22:37
|
|
|
|
|
#
?
Jan 1, 2016 20:15
|
|
|
Jesus christ, if that thing is remotely restorable, naming your price for a Hardinge 10EE clone from a reputable manufacturer is insane. If I lived in North Carolina, anywhere near that, I'd buy it and rent a storage unit for it if I didn't immediately have space at the time. You know, assuming it's not impossibly rusty and/or a scam.
|
|
#
?
Jan 1, 2016 22:39
|
|
|
Waldstein Sonata posted:Jesus christ, if that thing is remotely restorable, naming your price for a Hardinge 10EE clone from a reputable manufacturer is insane. If I lived in North Carolina, anywhere near that, I'd buy it and rent a storage unit for it if I didn't immediately have space at the time. So, just for fun (because I do have a garage) I found a deal like this.... How DOES one move a device like that? The heaviest thing I've had to move was an industrial sewing machine and an anvil, neither of which was over 400, so could be done by hand, carefully. With what can be rented in most cities, how does an every day person move this sort of thing?
|
|
#
?
Jan 2, 2016 00:29
|
|
|
Pagan posted:So, just for fun (because I do have a garage) I found a deal like this.... How DOES one move a device like that? The heaviest thing I've had to move was an industrial sewing machine and an anvil, neither of which was over 400, so could be done by hand, carefully. https://www.youtube.com/watch?v=BjksLl9xur0 You do it like that.
|
|
#
?
Jan 2, 2016 01:18
|
|
|
alright that might be my new favorite youtube channel.
|
|
#
?
Jan 2, 2016 03:20
|
|
|
fps_bill posted:alright that might be my new favorite youtube channel. He's a madman, and that's good for you and me.
|
|
#
?
Jan 2, 2016 06:11
|
|
|
Brekelefuw posted:https://www.youtube.com/watch?v=BjksLl9xur0 As soon as I heard the voice I thought, "Oh no... it's that guy again and this is going to be insane."
|
|
#
?
Jan 2, 2016 06:59
|
|
|
CrazyLittle posted:He's a madman, He's a goddamn skookum choocher. Keep your stick on the ice.
|
|
#
?
Jan 2, 2016 09:11
|
|
|
yeah when the zombie apocalypse comes that's the guy you need. Keep your dick in a vice.
|
|
#
?
Jan 2, 2016 09:54
|
|
|
|
| # ? May 25, 2024 16:48 |
|
|
I think I have watched every video he has done. He is funny, and know SO MUCH about stuff, it's crazy. Listening to him calculate clamping force, or the stats of a bearing etc in his head is mind boggling to me.
|
|
#
?
Jan 2, 2016 16:59
|
|