On Friday 12 August 2016 14:24:19 Gene Heskett wrote: > Greetings all; > > At what temp do I have to get a piece of hot roll to in order to > soften the ultra hard core of the steel? Is it something this toaster > oven can achieve given enough soak time at about 425F? > > Doing the hole, which I haven't tapped yet, for the 4mm gib adjuster > screw last night, I started with a freshly DrillDoc sharpened quality > 3.44mm bit. It looked good under the lens I use to inspect such > stuff. I setup a G83 to peck drill the hole, with full retract, 400 > rpms, f6 and .004" deeper per peck. By the time it was into this steel > by .150", I could see the G0704 flexing from the down pressure it took > to cut a chip about an inch long per peck. I was wondering if I was > going to smash and shatter that drill bit again, but it survived to > the -0.850 mark so I'd have room to tap deep enough to use a 20mm > screw for the adjuster screw. The flex was pushing the spindle fwd > about 20 thou, and the down pressure on the workpiece being held in a > vice caused the workpiece to lean to the rear at the same time by at > least 10 thou. That didn't break the bit, but I have a sloppy hole, > and I have no clue if that tap can survive peck tapping a second copy > of that hole. > > I had much the same problem building the front clamp. Cold rolled > would work much easier, but I'd have to buy that online, whereas the > hot roll is in the bins at TSC. > > Its big enough (1/2"x1"x4.5")I'd think it would take a blacksmiths > forge fire to heat it evenly enough. But I'm fresh out of that forge > thing. > > That $40 kilowatt induction heater might do it if I could find a power > supply. I'd think it would need water cooling for the coil, and a > glass tube big enough to pass the piece AND fit inside the coil just > to help hold in the heat. > > I have a toroid 2/1 isolation transformer thats probably good enough > that if fed from a 120 volt powerstat of suitable power, could do that > if I can find a suitable bridge or even discrete rectifiers, and some > capacitors to cobble up a psu for it. I'd need the bridge and the > powerstat. And a suitable hunk of 1/8" alu panel to mount the whole > thing on. It would need a crane to pick it up as that toroid is about > 90 lbs by itself. Obviously it would need a permanent home. But > where in my midden heap/shop/garage... > > Order placed, for a new 20 amp powerstat, 2 ea 50a 1000v rectifier > bridges, and the ZFS module. $137 on my card. Since the powerstat is > a 120 volt, I'll use that 2/1 transformer to feed it from my 240 > single phase power. Lets see, I'll need an aquarium pump, some > icemaker hose, a pan of water and a good sized fan. I can handle that > locally except for lifting the finished assembly. > > Cheers, Gene Heskett
I found a pdf, from ASM International, 18 pages describing in text and TT maps, what happens to steel as its heated and cooled. But somehow I am failing to make the connection to the temp, time at temp, and cooling rate to get the easiest to machine finished piece. Thats ASM #05144G. The fact that the TSC stuff carries no label describing its alloying materials and percentages is also "missing" info. I know in the early '50's that making the stuff drillable for cotter keys in the ends of some 5/8" shafting about 15" long was a matter of heating them pretty bright red on the ends, and air cooling, but other than necks of ammo being annealed for reloading longevity, that is about the extent of my knowledge if you throw in what you can do to a puddle of steel with a smith wrench. That is a whole science in and of itself. So, some recommendations, particularly for just the maximum machining ductility, and how best to measure that temp on the cheap, would be much appreciated. Thanks all. Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ What NetFlow Analyzer can do for you? Monitors network bandwidth and traffic patterns at an interface-level. Reveals which users, apps, and protocols are consuming the most bandwidth. Provides multi-vendor support for NetFlow, J-Flow, sFlow and other flows. Make informed decisions using capacity planning reports. http://sdm.link/zohodev2dev _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
