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General Metalwork question: I have an industrial cart that's all stainless steel. It's solid but it's got a ton scuffs, scratches, est. I'd like to get it cleaned up and looking nice again. What's the best way to go about it? I'd like to end up with a nice even matte finish, would a scotch bright wheel be the way to go for that? Or do I need to venture into the wold of polishes?
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Jul 9, 2014 16:49
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"scuffs, scratches" and "looking nice" is pretty subjective. The "best" way to get a pretty matte finish is probably to drop it down to your local grit/bead blasters and be done with it. As a rule of thumb: Deep scratches and gouges - Emery paper (sometimes called Wet 'n Dry), working with heavy grades (P120) through to fine (P1000) which will leave... Fine scratches - Scotchbrite pads, which will leave... Swirls and whatever - polishes
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Jul 9, 2014 17:09
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Bead blasting is my go-to for making SS look pretty.
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Jul 9, 2014 17:10
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Fine sanding disc to remove and blend deeper scratches. Emery paper wrapped around a block to smooth and remove small scratches. Scotchbrite to finish.
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Jul 9, 2014 18:10
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SmokeyXIII posted:That's a great story man. I wish we had a maker space in Edmonton. Since my career has grown away from welding and into QA/QC I get the urge now and then to go make things with metal. Hey uh hi I'm one of the directors at ENTS that's been filling out our metalworking area. Will post pictures when I'm not at work.
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Jul 9, 2014 19:00
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ReelBigLizard posted:"scuffs, scratches" and "looking nice" is pretty subjective. The "best" way to get a pretty matte finish is probably to drop it down to your local grit/bead blasters and be done with it. Thanks for the info. Back story: I took on a side gig repairing electric motors for a buddy's company. The motors comes mounted to a Stainless steel cart which gets thrown in the back of trucks and banged against walls, est. If I can, I'd like to return the whole unit back to him looking sort of detailed out. Again, it doesnt need to be show room new at all, I just want it to look like I put a little effort into making it look decent. Is there a wheel or something like that I can hit it with that will leave a passable finish? It's just going to go right back out into the field and get beat to hell again so there's no point in going to any great expense of time or money for this if that makes sense.
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Jul 9, 2014 20:53
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Mr. Bill posted:Hey uh hi I'm one of the directors at ENTS that's been filling out our metalworking area. Will post pictures when I'm not at work. Let's talk! I've got 10 years of alloy pressure welding experience and I'm just about (next month) qualified to certify pressure welders through ABSA. SmokeyXIII fucked around with this message at 00:23 on Jul 10, 2014 |
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Jul 10, 2014 00:21
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Delivery McGee posted:My brother and I have identical bottom-end Lincoln FCAW machines. His never works quite right, mine just trips a breaker if I ask too much of it. I can't quite put it into words what his is doing wrong, but it's probably because he's plugging it into a 50-foot extension cord, isn't it? 50ft extension cords assuming off the shelf at lowes are only rated for around 15 amps at 50% duty cycle. He'd need to make his own cord out of 6 gauge stranded if he really needs 50ft.
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Jul 10, 2014 13:20
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I'm glad everyone enjoys my story. Once I get it edited down I plan on submitting it to some local magazines. Now I have to decide what to do with this billet once it's ready. It'll make a big knife, so I have options. I'm glad I have some folks who can understand what an awesome experience it was, and I really appreciate all the help I got in this thread when I started on my own little garage forge.
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Jul 10, 2014 23:29
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Does anyone have any experience with inlaying other metals? In one of my older blacksmithing books, they describe a technique where you chisel a groove into iron, then heat up both metals and hammer the wire into the groove. When you're done, you've got iron with a brass line running through it. I experimented a little with it yesterday, but no success. It seems that brass melts long before iron gets up to forging temp. I then tried heating them separately, but even with a little bit of a red glow in the brass, it wouldn't stick to the steel.
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Jul 13, 2014 20:36
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http://en.wikipedia.org/wiki/Mokume-gane ?
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Jul 13, 2014 20:54
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I've seen Mokume-gane, but that's more like Damascus steel, just done with non-ferrous metals. I'm thinking something like this http://media.liveauctiongroup.net/i/8347/9752038_2.jpg This guy talks about a cold process http://www.seekyee.com/Bladesmithing/the%20process/tutorials/inlaytutorial1/inlaytutorial.htm
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Jul 13, 2014 21:50
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 Big Image Dump Post Ahead I am slowly working towards being a trumpet maker. Lately I have been making huge progress towards that goal. Here are some pictures of the stuff I am doing right now. Step 1. Get a copper tube. I use 5/8th tubing. I will switch to brass tube once I get a design that I like, but copper tube is $12 for 6 feet, and brass tubing of the same dimension is $90 for 6 feet.  Step 2. Get your biggest torch tip and anneal the tube you cut to length. I use pure acetylene. Let the tube cool slightly and then toss it in a bucket of water. Enjoy the sound of metal cooling rapidly.  While the tube is in the water, I start prepping the rest of the components for drawing the tube down to size. This is a zinc plated fender washer. I put the washer in a phosphoric solution to remove the zinc plating, and then anneal the washer. Don't add flame to zinc plating, because that is really bad for you. In the little clear pot is the washer I used. I am holding another to demonstrate. The black crud floating on top of the acid is zinc that has flaked off of the washer.  Next, I have to make the washer a little bit more friendly to drawing a tube with it. I made a small tapered rod, and then bored out a piece of .750" steel. I press the tapered rod through the washer to make it a funnel shape to facilitate the drawing process. I use my vice to press the washer over the mandrel, and then flip it around to release it.   Next, I take my annealed tube and form one end. The tip has to be hard in order to grip the mandrel I will draw the tubing over. I use a draw plate, a steel hammer, and a rod with a steel ball on it to form the tip. The rest of the tube stays nice and soft so it can easily be drawn.  This is my drawing machine. I made it myself. It is a winch, some steel square tube, and an angle iron with a hole bored through it.  I have a steel mandrel that I cut on my lathe that is the exact inner dimension of the tube I want to make. The mandrel is greased and the copper tube is placed over the mandrel which is threaded on to an eye-bolt attached to the winch cable. The eye bolt threads to through the washer as it is threaded on to the mandrel. The washer is what squeezes the tubing down over the mandrel. The outside of the tube is greased as well.  Here you can see the difference in size from the drawn side to the non drawn side. The tube starts at 5/8th I.D. and is brought down to .460" I.D. The wall thickness gets greater as you drawn tubing down, and the tubing also elongates by maybe 15-20%.  After drawing the tube, it is now VERY stuck on the mandrel.  To get the tube off of the mandrel I made a steel donut that is .001" larger I.D. than the mandrel's O.D. I flip the mandrel/tube around and thread the eye-bolt through the donut and on to the backside of the mandrel and draw it again.  Success!  While that was happening, I was double boiling my Cerrobend metal. It is a woods metal that melts in 152 degree water. This is used to bend the tubing without the tube collapsing or going out of round.  Coat the inside of the tube with a light oil and plug the bottom.  Fill the tube with the metal and then quench it for 15 minutes in cold water. You can see on the top of the metal is a layer of oil that is displaced as I fill the tube.  Get out my super high tech tube bending jig while the tube is cooling  Use Hulk strength to bend tube to correct radius  Two days ago, I drew a tapered tube on my drawing machine, and also machined a receiver with a morse #1 taper to fit my trumpet mouthpiece. I also machined two ferrules to attach the inner slide tubing to the curved main tuning slide that I showed above. After some careful measuring and tweaking, I aligned and soldered the stuff I made on to the trumpet. I can't make valves or bells yet, but the sections of tubing from the mouthpiece to the valve section was made by me. Hopefully I will be learning to spin bells in the next 2 years or so when I have some money saved up for the tooling. This is the final product. It now needs extensive testing and tweaking to figure out where I should place braces and/or add and subtract weight to dial in the playability of the horn. 
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Jul 13, 2014 21:56
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I am confused Brekelefuw by your "annealing," but it's probably because I've only learned about doing it with ferrous metals. If I took a piece of carbon steel, heated it up and then stuck it in cold water, I would be quenching it and the result would be hardening, not softening of the metal. By contrast, if I wanted to anneal a piece of carbon steel, I'd heat it to austenitic temp (conveniently slightly lower than the temp at which it loses magnetic attraction, so I can just heat it till it won't stick to a magnet) and then stick the work piece into some vermiculite or other insulator and allow it to slowly cool for a long time (like an hour or something). The result would be metal that is minimally hard and maximally ductile. I assume annealing copper is different, but can anyone explain why this doesn't make the copper (or bronze or whatever else) a lot harder and more brittle?
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Jul 13, 2014 22:45
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Leperflesh posted:I am confused Brekelefuw by your "annealing," but it's probably because I've only learned about doing it with ferrous metals. If I took a piece of carbon steel, heated it up and then stuck it in cold water, I would be quenching it and the result would be hardening, not softening of the metal. By contrast, if I wanted to anneal a piece of carbon steel, I'd heat it to austenitic temp (conveniently slightly lower than the temp at which it loses magnetic attraction, so I can just heat it till it won't stick to a magnet) and then stick the work piece into some vermiculite or other insulator and allow it to slowly cool for a long time (like an hour or something). The result would be metal that is minimally hard and maximally ductile. I am not a metallurgist, but my understanding is that it's because of the carbon in the steel. When you heat steel past the critical temperature the carbon is free to wander around a bit and it makes its way inside the now open iron structure. If cooled slowly, the carbon gets squished back out of the iron crystals leaving it ductile. If cooled quickly, such as by quenching, the carbon atoms get trapped inside the iron crystals resulting in a hard piece. This is why maximum hardness of a steel depends so heavily on the carbon content of the alloy.
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Jul 13, 2014 23:15
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Copper alloys don't harden when quenched. Annealing copper and brass also doesn't require them to glow. You can take them until they get shiny silver/blue and that is good enough. The only thing you have to watch out for, and the reason that I let it air cool for a minute before I quench is to reduce the chance of it warping as it hits the water. Copper alloys also don't temper the way you can do that with steel. You can heat harden them slightly, but nothing like case hardening. A few hours at 400 or so will make the metal be a bit more firm. Cryogenics also don't affect them.
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Jul 13, 2014 23:29
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TerminalSaint posted:I am not a metallurgist, but my understanding is that it's because of the carbon in the steel. This is basically correct. Each grain type of steel can absorb a different percentage of carbon. So as the steel passes through the different allotropes the carbon gets squished around. Austenite exists at high temperature (about 723c dependant on alloy) and absorbs a fair amount of carbon. When it cools slowly the carbon dissipates from the austenite into the cementite layers of the pearlite grains and everything is nice. When you slam it from hot to cold the carbon can't dissipate and forms martensite which is oversaturated with carbon and the structure suffers a lot of stress in the material. It looks like shattered glass or a pile of toothpicks at a microscopic level. http://i.imgur.com/Q3UXxu0.jpg SmokeyXIII fucked around with this message at 02:06 on Jul 14, 2014 |
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Jul 14, 2014 01:03
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Pagan posted:Does anyone have any experience with inlaying other metals? In one of my older blacksmithing books, they describe a technique where you chisel a groove into iron, then heat up both metals and hammer the wire into the groove. When you're done, you've got iron with a brass line running through it. I experimented a little with it yesterday, but no success. It seems that brass melts long before iron gets up to forging temp. I then tried heating them separately, but even with a little bit of a red glow in the brass, it wouldn't stick to the steel. Essentially the process is the same as "Brazing" It's far easier to do with a MAPP-Gas or hotter torch. Essentially the process is bring the steel up to cherry red, then take the metal with the lower temp and work into the grooves or joints, working the torch in concentric circles working both the steel and the filler metal until it starts to pool and melt into the crack. https://www.youtube.com/watch?v=HvYO2_84oOU This essentially.
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Jul 14, 2014 04:00
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If anyone's interested: the reason that the martensite make the material harder is that it has a lot more grain boundaries between carbon and iron. These grain boundaries make it difficult for the material to "slip" past itself when force is put on it, since particles don't move between the grains. The grain boundaries are a form of dislocation, a defect in the grain structure. These planar defects prevent other defects in the material from propagating, since they can't slip past each other. The more grain boundaries, the harder the material and the higher the yield strength, but the more brittle, since it can't plastically deform as much. Copper does harden similarly, but not by heat-treating and forming grain boundaries: it work-hardens like all hell, forming dislocations under stress. I don't know whether they anneal the tubing after rolling/extruding it (probably), but if not, it's going to be very difficult to bend without breaking. You can basically reset the work hardening by heating it up and letting all the dislocations relax.
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Jul 14, 2014 04:31
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irt cuprous alloys, the simplest rule is that they work the opposite of steel when it comes to heat-treatment- quenching softens while slow controlled cooling hardens and tempers. It's a tidy n convenient arrangement.
Ambrose Burnside fucked around with this message at 01:38 on Jul 15, 2014 |
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Jul 14, 2014 06:20
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also, how much does it cost y'all to get lil MC caddy-tanks filled? there's no goddamn way almost $100 Canadian is right. e: I'm definitely bringing the cylinders back and asking them some questions cause the relief valve on the oxygen tank must be busted, it starts venting at some absurdly low pressure (I can't even pressurize the regulator without the tank relief kicking open, which manifestly Should Not Happen) e^2: Yep, they charged me for an MC and a B tank instead of the cylinders i actually got, and also, the oxygen tank is faulty. Good work all around, guys. Ambrose Burnside fucked around with this message at 02:12 on Jul 15, 2014 |
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Jul 14, 2014 06:21
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Speaking of brass/copper metals. I recently came across a Rancilio dual group head espresso machine. In the process of taking it apart to clean the guts, I found that the front double boiler tube has split on the backside. The boiler is chromed copper or brass (I'm guessing brass) and a replacement boiler is not easily forthcoming on a google search. Is it possible to fix that boiler or is it very expensive scrap?
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Jul 15, 2014 03:23
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Strip the chrome and braze it back together. Not a difficult repair if you know how to braze.
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Jul 15, 2014 03:59
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Brekelefuw posted:Strip the chrome and braze it back together. Not a difficult repair if you know how to braze. So it turns out Rancilio wants about $1k for a new boiler. So here's my plan:  (The bad tube is badly circled in blue). Mount the boiler in the bridgeport, and mount a hole saw big enough to go around the fitting. Cut out both sides, slide the tube out, flatten the split, braze that, slide it back in and braze it back to the tank. Seem workable?
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Jul 16, 2014 00:59
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I'm not sure I understand the part you want removed. Is the damage on the little arms sticking out of the main body, or the parts labelled 24,41,8,12? I'm not sure exactly what you need to cut out with a hole saw. The little nozzles look to be threaded in. If the metal is thick, you will never get it hot enough to braze. You also need to remove all the chrome on the part being brazed for health reasons. I can post a few pictures from some crack brazing that I have done when I get some time tomorrow. Ideally you would clean up the crack with a small triangle file so there is a V shaped groove along the crack. Then you would form the sides of the crack so they are touching again (because brazing doesn't fill gaps well,) and then you would flux and braze and then do your final cleanup with files and sandpaper and buffing compound as needed. If done well, there can be no cleanup other than washing flux residue off and removing the fire scale and discolouring.
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Jul 16, 2014 04:20
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From what he was saying, it's implied there is a pipe traveling through the centre of the boiler between the two fittings you see on the outside.
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Jul 16, 2014 05:00
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I assume we allow horror stories in here? Today, I came in to work, and took inventory of our hydraulic toolholders. Two were missing setscrews. There was a loose setscrew sitting on the shelf next to it, utterly stripped. Someone had over-torqued it. Surprisingly, the holders still clamped, but one had 0.001 of runout, and the other had 0.003. That's about $1500 of toolholders. Scrap. I think I might cry. (For reference, I work in a college shop. So it's probably not a coworker, more likely a student. That cabinet was supposed to be locked for a reason.)
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Jul 16, 2014 23:33
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Kim Jong ill posted:From what he was saying, it's implied there is a pipe traveling through the centre of the boiler between the two fittings you see on the outside. This may make it clearer:  You might be able to make out the swollen part of the pipe, directly below that pipe is where it split. Brekelefuw posted:I'm not sure I understand the part you want removed. I had planned on knocking the chrome off with a grinder stone on a high speed tool. I have also heard that you can arc weld brass with nickle rods. Pimblor fucked around with this message at 23:45 on Jul 16, 2014 |
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Jul 16, 2014 23:37
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How long can I reasonably leave my oxyfuel regulators pressurized for? Quibbling over a little bit of gas seems silly, but as long as I'm using teeny little caddy tanks (that cost a FORTUNE to fill even compared to B tanks, oh my god) and a jeweller's torch, draining the regulators every time I wanna go back to the bench and tinker for a bit is a non-negligible waste of gas.
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Jul 17, 2014 00:07
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Ambrose Burnside posted:How long can I reasonably leave my oxyfuel regulators pressurized for? What's more expensive to you: gas refills, or regulator seals/springs? I wouldn't leave an air pressure regulator gassed up for months at a time, but there's no harm (to the regulator) in a few days. Also regulators typically have an over-pressure bleed off valve, so make sure there's adequate ventilation while the system is charged / in use. You don't want small amounts of gas leaking to accumulate.
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Jul 17, 2014 01:20
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That's better than I figured. As it stands I'm still superstitious about The Gas That Is Trying To Autoignite Continuously so I'll make sure everything's fully shut down and unpressurized by the end of the day.
Ambrose Burnside fucked around with this message at 02:08 on Jul 17, 2014 |
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Jul 17, 2014 01:47
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Ambrose Burnside posted:That's better than I figured. As it stands I'm still superstitious about The Gas That Is Trying To Autoignite Continuously so I'll make sure everything's fully shut down and unpressurized by the end of the day. I've left oxyfuel regulators on for days at a time (day shift / night shift) and they still work out. Likely out of calibration but the numbers on the gauge don't matter anyways. Also I've never heard of acetylene autoignition happening to anyone I know, or anyone they knew. I know that theoretically it can happen but even when our regulators have overpressured past 15 on the regulator gauge nothing happened.
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Jul 17, 2014 02:04
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I gotta say tho, yeee-hah. Wanted to put my Little Torch to a proper test, so I tried fusion-welding some large copper jumprings, something I could never do with a plumber's torch running propane and only very reluctantly (and by heating the whole ring up red-hot) with MAPP. Once I worked out the right tip and flame, oxy-acetylene does the job zip-zip-zip, 15 seconds per ring, not much residual heat, no biggie. I'm in love  I don't think I'm gonna do much steel welding with it, but I'm still gonna make some puddles on some 16-gauge mild sheet when I can round up some wire or rod that isn't already galvanized.
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Jul 17, 2014 02:08
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Karia posted:I assume we allow horror stories in here? Today, I came in to work, and took inventory of our hydraulic toolholders. Two were missing setscrews. There was a loose setscrew sitting on the shelf next to it, utterly stripped. Someone had over-torqued it. Surprisingly, the holders still clamped, but one had 0.001 of runout, and the other had 0.003. That's about $1500 of toolholders. Scrap. I think I might cry. What's a hydraulic toolholder?
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Jul 17, 2014 04:50
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Hu Fa Ted posted:What's a hydraulic toolholder? http://www.mmsonline.com/articles/why-use-hydraulic-toolholders Basically, it's a type of milling toolholder that uses a hydraulic bladder to hold the tool. Put your tool in the bore, tighten a setscrew. That expands the bladder, which shrinks the bore down onto the tool. The setscrew goes to a pretty obvious stop, but if you force it past that? You can burst the bladder or permanently deform the bore. They're used for high-rpm machining a lot, since they've got good balance and very good runout (they should have about 0.0001 of runout. Not 0.003.) We use ours for both heavy roughing (since they have very high clamping forces) and finishing (because of the low runout.)
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Jul 17, 2014 06:16
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Any tips or advice on buying a handheld torch? Are they all pretty much the same, or is there a difference? My main use will be to heat up metal for bending and twisting. I'm thinking something like this
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Jul 17, 2014 12:41
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From personal experience, a handheld plumber's torch is going to choke on stock larger than ~3/16" and be incapable of heating up much more than an inch or two of metal at a time, unless you build a firebrick shelter to help trap the heat. Within those limitations, though, they work great. I'd go with a torch that has a length of hose between the regulator and the torch, though- if you find yourself standing over/above your work, controlling the flame becomes extremely difficult when you tilt the bottle and start burning liquid propane. Also preferably something with swappable tips for different types of flame and/or adjustable choke, if at all possible, but I forced my torch into all sorts of odd jobs that could require a big bushy heating flame or a focused jet or anything in between- you might not have the same needs in that particular regard.
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Jul 17, 2014 13:12
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Pagan posted:Any tips or advice on buying a handheld torch? Are they all pretty much the same, or is there a difference? My main use will be to heat up metal for bending and twisting. I'm thinking something like this Ambrose is right, the little propane torches have their uses, but they are pretty limited. When I use a torch like that, I prefer mapp. Same style, better heat. I used mine to put some precision bends in O1 tool steel... I think it was 5/16ths, round for a triangle last year. Worked great, but that was right around the limit of usefulness and it took a while to build heat even with two fire bricks. The propane is so limited I'd only use it for 1/4 or less. Makes for a great forge lighter though. I don't think I'd attempt to twist with it. You probably want to heat up at least 5-10cm at a time to make anything more than the most teeny of decorations. Slung Blade fucked around with this message at 16:29 on Jul 17, 2014 |
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Jul 17, 2014 16:26
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I got a lot of mileage out of my propane plumber's torch by building a firebrick microforge for it- which it turns out I did a sketchup of, way back in the day. doesnt work quite as well as a paint-can forge and is pretty fragile but it's dead simple and performs very well for what it is. two standard soft firebricks. measurements are iirc completely arbitrary, ignore them. you'll also need two hole-saws: iirc, 2 1/2" and 1".  saw each in half.  leave one piece intact (the bottom piece in the stack), drill through two in one pass with the 2 1/2" hole saw, and additionally drill through the side of one of those cored blocks with the 1" saw tangential to the side of the central chamber. set fourth brick aside for now  see? tangential.  (pictured standing up, should be on its side, with binding wire or straps used to hold the four segments together) drill fourth block like the other two, except with the 1" saw, to act as a vent/passthrough door for stock. It could get close-ish to forge-welding temps with MAPP, but only on small stock. Then it fell apart, 'cause soft firebricks are fragile. RIP my lovely tiny two-brick forge. Ambrose Burnside fucked around with this message at 00:02 on Jul 18, 2014 |
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Jul 18, 2014 00:00
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| # ? May 24, 2024 20:06 |
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I'm making my own copy of the military-issue metal "sheath" for my new Woodman's Pal, because the canvas and nylon sheaths they sell are overpriced and a bit awkward to use. It's going quite well: I'll probably stack up some bits of plastic and pop-rivet it on instead of trying to repousse the metal for the hook-guard bit. After that, I just need to paint it (I'm thinking plastidip spray, to be gentle on the blade finish), and work up a leather belt loop and holding strap (or maybe a spring clip like a mop hanger, for easier drawing/resheathing). So far I've done everything with a pair of tin snips, a bench vise, a 4-pound hammer, and a bit of scrap sheetmetal (originally a sign from a grocery-store spice rack). Edit: the other side is more obvious as to where I got the metal: 
Chillbro Baggins fucked around with this message at 14:54 on Jul 18, 2014 |
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Jul 18, 2014 14:42
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Bad Angus! Bad!