On Wednesday 09 September 2015 06:52:01 Erik Christiansen wrote: > 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.) > Must be. It would be "methanol" here I believe. Quite dangerous as its quite flamable and it burns with an almost invisible blue flame. A fuel line leak thats burning is impossible to see out in the daylight environment of a top fuel dragster. > ... > > > 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.)
Now thats hard alu. I've cut 7078-T6 but it was not that hard, my toy mill had what it took. > ... > > > > 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. I considered that, but the smallest of those I have is about the drill size needed for a 4mm thread, so I didn't make the walk up the hill to get the kit. I did sharpen the bit I used a couple times as the shaft steel was harder to cut than the flywheel forging. Neither are particularly hard, but I only had 1/4" sticking out of the chuck so I just fed it very slowly and moved the mill until the starting dimple was where I wanted it. Good enough for the girls I go with. :) > > > > 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? Probably. OTOH, they are used to the mad scientist I am, and likely wouldn't run unless it went boom. > > 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 Link blocked, with a "doing maintenance" graphic. > I'd ask for "soluble oil cutting fluid'. > (You can dilute that 1L pack to 20L, with water.) Or similar wording is what I had in mind. With the lathe being such a problem child, that aspect has not been given any great amount of time/research. It, like the tool changer, is on my bucket list. And by now I should be having to walk around a pile of Mahogany 1x12's, 12 foot long in the garage, and I am not. I may call them when the lathe is working again so I can finish the spindle lock I have started. And now I really should get back to reassembling that lathe, if the overnight slow run hasn't screwed the moose. Thanks Erik 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> ------------------------------------------------------------------------------ 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 Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
