On Sunday 10 February 2013 09:56:28 Dave did opine: Message additions Copyright Sunday 10 February 2013 by Gene Heskett
> On 2/10/2013 9:05 AM, Gene Heskett wrote: > > On Sunday 10 February 2013 08:34:10 Mark Wendt did opine: > > Message additions Copyright Sunday 10 February 2013 by Gene Heskett > > > >> On Sat, Feb 9, 2013 at 7:15 PM, Steve Blackmore<st...@pilotltd.net> > > > > wrote: > >>>> That may work for most 'Murkan made machines, but those with the > >>>> made overseas in Asia tend to have a pretty lousy fit for the > >>>> standard grease gun fitting. > >>> > >>> Hi Mark - oil nipple heads often aren't the same size and shape as > >>> grease nipples. Myford's were fitted with oil nipples, not grease > >>> nipples. I still have the original Wanner oil gun off one. It > >>> doesn't clip on the nipple. The end is simply a recess that you > >>> push against the nipple and pump. > >>> > >>> There's a link on this page that shows oil nipples (and the > >>> expensive pump ;) > >>> > >>> http://www.lathespares.co.uk/oil-lubrication-c-31/wanner-oil-gun-for > >>> -t he-myford-lathe-new-p-646 > >>> > >>> The round head type nipple generally has a smaller diameter head > >>> than a grease nipple with the same thread. > >>> > >>> Plenty of Myford spindles were damaged though by people forcing > >>> grease into them using those grease guns with an adjustable > >>> clamping nozzle. It often forced the wick (hidden in the hole) into > >>> the bearing.. > >>> > >>> Steve Blackmore > >> > >> Steve, > >> > >> Yah, I'd heard about some of the horror stories where folks had > >> forced grease into an oil fitting. That was why I was concerned for > >> Gene when he mentioned his grease gun wouldn't fit the zerk. A > >> number of guys on Practical Machinist had bought machines where the > >> previous owner had forced grease into an oil fitting, and left a > >> mess. > >> > >> Gene, check the link for the image of the two type oil fittings at > >> the bottom of Steve's link. Does your zerk look like either of > >> those? > >> > >> Mark > > > > The photo isn't as clear as it could be. However folks, we aren't > > talking about a high speed spindle. This is a ball nut on a 16x5mm > > screw, that I was able to get 60 ipm rapids out of last night with a > > 2/1 geardown so the motor is charging right along, thinking I was > > home free, but the backlash setting I needed was excessive IMO, > > someplace in the .0045" to .0048" range, which seemed awful sloppy > > for a ball screw that was supposedly a C7 grade. Turns out there is > > zero preload on the angular ball bearings in the drive end bearing > > block regardless of the torque applied to the tensioning nut. > > > > So, I need a 12mm bore, 18mm OD, .2mm thick shim washer to space the > > center races apart far enough that when I put the end cap back on the > > block, pushing in on the outer races, they will then be preloaded > > about a thou. Or is that too much crush? .1mm is the thinest I can > > get, but that will only take up about 60% of the end play which as > > is, looks to be as above, measured on either end of the screw. > > > > Besides, the grease fitting has been replaced with a Murican version > > (finding that turned into an all afternoon job Thursday) and the nut > > has been greased enough to push a small amount past the felt (or > > whatever, its white, wipers at each end of the nut. Since its maxed > > at maybe 300 rpm, std lithium grease will make it outlive me. > > > > It turns out, in my tour of the place looking for suitable shim > > material, that the alu slider on a 3.5" floppy disk is about that > > thickness. But cutting a shim out of that would probably be an EDM > > job to do it neat enough without burrs on the edges. Unless somebody > > else has an idea. > > > > McMaster-Carr has them in either 316 or 18-8 SS, straddling a $10 bill > > but whats their minimum order? More than a tenner IIRC. > > > > Cheers, Gene > > I don't know what Gene's fittings looked like, but if you look at this > page, the top brass fitting looks somewhat like a conventional zerk > fitting, but to me, the nipple looks a little long. > > http://factory.dhgate.com/other-auto-parts/10-1-straight-grease-zerk/gre > ase-fitting-p43044204.html > > Scroll down and you will see some straight fittings that are truly > straight on the sides of the nipple. I have no idea why a straight > grease fitting would be a good idea, but I've seen > fitting such as these on Chinese hydraulic jacks and some other Chinese > equipment. Apparently you hold a grease gun against the fitting?? But > those do not work at all with a conventional grease gun. > > http://factory.dhgate.com/other-auto-parts/10-1-straight-grease-zerk/gre > ase-fitting-p43044204.html > > I think this company should hire a more competent translator. > > Dave Yeah, there's some real NSFW's there. Anyway: <http://factory.dhgate.com/other-auto-parts/10-1-straight-grease- zerk/grease-fitting-p43044204.html> Slide down to the bottom pix, and while the thread is obviously not a 6mm, note that the profile below the major diameter isn't convex, but concave. Put a 7mm hex and 6x1 bottom on it and it would look pretty close. It is actually a better finished fitting than anything I've ever seen on this side of the trench (marianas). That is what the OEM fitting looked like. I found a std Murican head, 90 degree and have that installed now, works well. To finish up, I need a 12mm ID, 18mm OD, .2mm thick shim washer to take up some end play in the not quite preloaded angular thrust bearings. The whole screw is walking back and forth in the bearing by just a red hair under 5 thou! I may have found some material, the slider from a 3.5" floppy disk is about the right thickness, but I wonder if ALU will stand the music. That carriage is hard to push until it wears in again. But cutting it out sure looks like an EDM job to me unless somebody else has a better idea? By the time I can get a SS one from McMaster-Carr with their min order, I'll have another $50 in this, not to mention the 15 days it takes to get it, they do shipping is by ox-cart I think with only the last 20 miles by UPS. I am also amazed at the relative lack of grease in the thrust carrier, and no grease fitting to slip a pump squirt in between the bearings occasionally. It will go back together again only after I pack them plumb full. Or I drill and tap for another of the fittings from that 10 pack I bought Thursday. So I'm looking for suggestions I can do in an hour. I have even considered putting one bearing back in and the bolt thru it, and a good layer of grease on the face of the inner, and a length of Dee's smallest yarn pressed into the grease to hold it in place while I drive the 2nd bearing in with the clamp nut. Once that done, take the nut back off & install the end cover which will then preload the now longer bearing stack. I wonder how long that would last?, says he to nobody in particular. No clue what that yarn is made of, or what the grease would do it it over 5 years or so. More than long enough to forget its in there given the short term memory that goes with the years on this too sweet wet ram. :( Thanks Dave. 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! My views <http://www.armchairpatriot.com/What%20Has%20America%20Become.shtml> If you explain so clearly that nobody can misunderstand, somebody will. I was taught to respect my elders, but its getting harder and harder to find any... ------------------------------------------------------------------------------ Free Next-Gen Firewall Hardware Offer Buy your Sophos next-gen firewall before the end March 2013 and get the hardware for free! Learn more. http://p.sf.net/sfu/sophos-d2d-feb _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
