Greetings all; I left the mill, running in the dark last night, doing the taper on about .310" width of a brass bar about an inch wide. The last time I did that for the first gib, I've been working on with a drawfile and a hammer to get it somewhat straight as it even twisted about 3 or 4 degrees in its length in addition to warping about 1/2" in both directions.
I read a link last night that said about 90 minutes at 500F would stress relieve it so that it didn't warp and wind as much when I cut this piece off the edge of the bar. The guy slightly missed the temp because his toaster oven only went to 450 degrees so he added time to the soak. And it seemed to work in that he didn't get as much warpage making gibs. Has anyone some experience in this, and can recommend a toaster oven thats known to work for this? Wally's probably has 3 or 4 different brands on the shelves & I'd like to get the best one for this job. Read cheap, and a calibrateable thermostat. I figure I could tighten the screw half a turn, set it for say 200F, use my IR thermometer that overflows at 399 degrees F, then use the error added to the dial setting to get, if it can, closer to the desired temp. Snipping from that text: In order to relieve internal stresses without loss of properties a low-temperature anneal such as 1⁄2 to 1 hour at 250-300°C should be used, dependent on section size. Thats 482-572°F so 525 would seem to be the middle on that range. Full text at: <https://sites.google.com/site/lagadoacademy/machining---lathes-mills-etc/brass---stress-relieving> Several of the additional reading links near the bottom of that page no longer exist. Bitch rant: This is the sort of info that s/b in the Machinists Handbook. But my #27 devotes several pages to defining the various alloys of brass, and totally zip on heat treating it and very little the other properties. Thanks everybody. 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> ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
