Castor oil is a good guess but not the only one. It's fatty acids are a couple of carbons longer than the average cooking oil and does seem to survive well as a lube in model airplane engines. On the industrial market it is about 30% more expensive than canola. If I wanted to go cheap I'd simply go with canola right off the shelf. Indeed inexpensive enough to not recover.
Tea (seed) oil might be another interesting choice. About 88% C18:1 (mono-unsaturated) it has a high smoke point (485 F). Common cooking oil for southern China and available in this country as specialty cooking oil. If you wanted something different blend fat from hamburgers with canola and enjoy the smell of frying beef food while machining. ;-) Probably more than you really wanted to know. Dave On Sun, 2009-11-15 at 20:57 +0200, Roland Jollivet wrote: > If it's organic, it's bound to be Castor oil, an excellent lubricant. > Because it gums up over time, you could just let it go to drain. > > http://www3.towerhobbies.com/cgi-bin/WTI0001P?I=LXS627&P=8 > > Roland > > > > 2009/11/15 Leslie Newell <les.new...@fastmail.co.uk> > > > Here is how I did it. I took a short piece of brass bar and drilled most > > of the way through with a drill slightly bigger than the smallest tube I > > could easily obtain. This creates the air jet. I then drilled the rest > > of the way with a drill the same size as the tube. Next I drilled > > diagonally in from the back to allow air to pass around the oil pipe to > > the air jet. The small tube is pushed right through and soldered in > > place. It projects about 1mm past the end of the jet. The whole lot is > > then pressed into the plastic nozzle on one of those cheap loc-line > > hoses. A small plastic pipe runs from the small tube in the jet, down > > the loc-line and out of a made-up block at the bottom. It sounds more > > complicated than it is. > > > > I found the trick is to make sure the pipe down the middle projects past > > the end of the air nozzle. This way you get a stream of fine droplets in > > a cylinder of fast moving air. If the oil pipe is flush with the air > > outlet you get a fine mist that hangs in the air rather than going on > > the work. > > > > Note that I use a pressurized oil feed as this setup doesn't generate > > much vacuum. The pressurized oil is supplied with one of those cheap > > combined air regulator/filter and oiler units on eBay like item > > #250528218868. I took out the air filter bits and added a pipe fitting > > on the bottom of the water trap. The water trap now becomes the oil > > reservoir. The reservoir is only small but it lasts quite a long time as > > you only need a trace of oil. > > > > It pays to use oil designed for misters as it is less toxic than the > > usual cutting oils. The stuff I use is vegetable oil based and a gallon > > was damn expensive. However it will last many years. > > > > Les > > > > > > > > I used the smallest tube I could find. > > > > Gene Heskett wrote: > > > Greetings all; > > > > > > I find that I can get brass tubing in pretty small sizes, like 1/16" OD, > > > usually sized to be a slip fit in the next larger size, so this makes it > > easy > > > to solder up a small nozzle, with the far end built up to 1/4" for > > attaching > > > the air supply. > > > > > > Now, I'm wondering if there is a standard formula that would tell me the > > > exact geometry it would take to make a 2 tube, one blowing across the end > > of > > > the other with air, and the second pulling from a nearby quart of cutting > > > oil, in the same manner as the old hand pumped Hudson sprayers, to add a > > > slight mist of cutting oil to the air blowing on the mill? Angles, > > center > > > separations etc? I think I can just solder the tubing(s) to another > > small > > > piece of sheet brass to maintain the alignment. > > > > > > > > > ------------------------------------------------------------------------------ > > Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day > > trial. Simplify your report design, integration and deployment - and focus > > on > > what you do best, core application coding. Discover what's new with > > Crystal Reports now. http://p.sf.net/sfu/bobj-july > > _______________________________________________ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > ------------------------------------------------------------------------------ > Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day > trial. Simplify your report design, integration and deployment - and focus on > what you do best, core application coding. Discover what's new with > Crystal Reports now. http://p.sf.net/sfu/bobj-july > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
