On Saturday 18 August 2012 19:12:06 John Kasunich did opine: > On Sat, Aug 18, 2012, at 10:59 AM, Kenneth Lerman wrote: > > On 8/18/2012 9:49 AM, Gene Heskett wrote: > > > On Saturday 18 August 2012 09:46:26 Kenneth Lerman did opine: > > > [...] > > > > > >>> I have done quite a few 6-32 holes in 7078-T6 but can't claim a > > >>> lot of experience in tapping the common alu stock sold at > > >>> Lowes/TSC, its pretty soft. ISTR the last batch of 4-40's I > > >>> tapped about 3/8" deep, blind, took about 4 trips back out to > > >>> clear the chips. Not much chip room in a common hand tap. > > >> > > >> Try using roll form taps. They don't generate chips. > > >> > > >> Regards, > > >> > > >> Ken > > > > > > Do they not require near breakage torque and EP lubricants? > > > > > > Cheers, Gene > > > > I've only used them in aluminum and never broken one. I usually brush > > the tap with a little motor oil. I don't know what is recommended. > > My understanding is that you need to drill a slightly larger hole > for form taps. Trying to use standard tap hole sizes leads to > breakage. (Haven't used them yet, just bought a few last week > because I got tired of picking chips out of blind holes.)' > > I usually use gear oil for tapping - it has high pressure > additives.
I wondered about that, something labeled hypoid oil I assume. For rear axles etc. I am about done with the ball nut cage, it is ready to have the nut pressed or driven in, but I haven't cobbled up the code to drill the hole pattern in the 4 corners of it, and the corresponding pattern for some smallish cap screws to bolt it to the bottom of the crossfeed table yet. The nut cage will hit the front V-way, costing me about 10mm of outward motion, so I'll mount it about 10mm inward of the old nut to get that back. As I can leave this bolt longer, I can also get back some of the inward motion that I have been forced to use the compound for. With luck, I might get enough range that the compound can go in a bottom drawer for good. That would stiffen up the whole tool holder lash up. When I am ready to put it together, I'll take some pix & put them up. Cheers, Gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) My web page: <http://coyoteden.dyndns-free.com:85/gene> is up! I don't think it's worth washing hogs over. -- Larry Wall in <[email protected]> ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
