On 08.09.15 10:09, Gene Heskett wrote: > > As has been mentioned here before, Gene, keeping chewing-gum grade Al > > cool is the trick, and metho does that very well, without mess. > > Metho? Thats a slang I've not encountered.
Whoops, that may then be an Australianism. It's just Methylated Spirits, i.e. ethanol with a trace of something to discourage drinking it, typically pyridine, I think. I'll have to admit that I don't know what it's called in baseball & gridiron territory. (Did spend 10 days in Texas, once - not long enough to pick up the language.) ... > Some of the 1/2" plate I made that jackshaft frame out of must have quite > a bit in it, it machines great, but sounds as if I am grinding glass. Some age hardening Al I alloyed with a bit of Cu and bit of Zn (decades ago) went so hard that a round-column mill-drill baulked at cutting it. I had to take it home, anneal it in the oven, and ask the operator to try again before it re-hardened. (IIRC, tensile strength can be taken from 10 T/in^2 to 25.) ... > > > Yesterday, though, I just cranked up the spindle RPM so the chips were > > flung off, and forgot about coolant on two pieces of extrusion, it > > went so well. > > My facing went well, 1/4" bit, 3mm stepover, 1100 revs and about 450 > mm/minute feed. And a bit of wd-40 when the bit looked as if it was > starting to pack. That's a 20 mm circumference bit, so 22 m/min cutting speed, i.e. 1/5 of the minimum recommended in the machining book I have lying here, but on many a mill, hard to even double. Looks like we all need a high speed spindle. The feed/tooth looks good, though. > And the jig to hold the motor worked well enough once I found a decently > sharp pilot bit. That big chuck is a bitch, as it will not hold a drill > under 3mm shank, so a 1/16" bit wasn't usable. So I need to obtain > another R8/smaller jacobs shank (or a 3/8" threaded one) & mount a > smaller drill chuck. Thats stuff for my bucket list... A small diameter drill bit is also likely to wander. In the absence of a spotting bit, a centre drill (Slocombe bit) grabbed from the lathe is an adequate hole starter on the mill, I find, and is well over 3mm in the shank. > > Piping kero about the workshop sounds distinctly scary to me. > > Me too. I don't smoke anymore, quite about 27 years ago, and in the usage > for EDM, I haven't ever had a fire even when using a big enough power > supply that it could be heard a coule blocks away when running. The locals could hear it a range of couple of blocks, while running away? ... > Water soluble oil? Heavy on emulsifiers I expect. The emulsifier's included. Just add water. > What do I ask for? Here's a typical product: (Just a poor choice for shipping, in your case.) http://www.machineryhouse.com.au/S090A I'd ask for "soluble oil cutting fluid'. (You can dilute that 1L pack to 20L, with water.) Erik ------------------------------------------------------------------------------ Monitor Your Dynamic Infrastructure at Any Scale With Datadog! Get real-time metrics from all of your servers, apps and tools in one place. SourceForge users - Click here to start your Free Trial of Datadog now! http://pubads.g.doubleclick.net/gampad/clk?id=241902991&iu=/4140 _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
