17 Apr 16
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Originally posted by moonbusSS is a bitch no doubt. I hate to drill it, cut it, dremel it, anything.
I found brass the most fun to cut on machine tools, stainless steel the least.
I recently had a job where I had to drill and tap a BUNCH of holes in a SS plate about 1/8th inch thick. You wouldn't believe how many of the toughest drills I could get at McMasters to get that job done.
And tapping. Jeez. I found out the hard way you don't believe the tap tables. I had to use taps so much smaller than the book says I was just cutting a few thousands into the metal. It worked because the finished product was to hold alumina substrates about a 12 mm wide and 100 mm long with micro sized gold electrical connections on them, literally hundreds of them, then process them through a sputtering machine.
I proved you had to use conductive shadow masks to keep from burning up micro sized resistors in the substrate. So I was the one assigned to do the engineering and building on the new set of aluminum shadow masks and then prove the concept worked, namely to keep from burning out the resistors under the influence of the sputtering machine which uses over 1000 watts of RF at 13.56 Mhz (one of the 'medical' frequencies, ok for industry to use)
Now they send the design out to a real machine shop to make the shadow masks and THEY have to deal with the crappy job of drilling and tapping that SS plate.
19 Apr 16
Originally posted by Ghost of a DukeOne of the most challenging things to do on a lathe is to cut internal threads in a tube (not with a tap, I mean). Challenging because one could not see where the cutting tool was; one had to position the cutting tool by turning cranks and then read the cutting depth off the dials--no cnc in my day as an apprentice, but I had two journeymen machinists to learn from.
Am so out of my depth in this thread, but am learning something.
19 Apr 16
1 edit
Originally posted by moonbusOnce I had to build a small air pressure switch, and decided to design and build it from a piece of aluminum. What it was actually, a piece of 100% pure aluminum. To my dismay I found even drilling into that little slab distorted the whole piece. I took it as a challenge however and persisted, reshaping it after every machining affront to the piece. Eventually I succeeded in making my little pressure switch and it worked perfectly but I vowed never to build anything like that again with pure aluminum. I learned my lesson well🙂 It was like trying to build something with chewing gum🙂
Aluminum is lovely to mill and tap, but not to file. It tends to load the file very quickly and you spend half your time just brushing the file clean again.