On Tuesday 30 June 2015 10:53:58 Tom Easterday wrote: > I am learning to use a CNC lathe. I like to learn from the mistake’s > of others by repeating them myself ;-)
Chuckle, BTDT, fun but hard on tooling. > I am cutting medium carbon > steel (medium because I don’t really know what it is - not stainless, > not tool steel, turns/faces easily enough). I have a narrow (0.088”) > cutoff bar with a carbide insert. I used a program that I have called > GWizard to get feeds and speeds and on it’s conservative setting for > carbide cutoff tool in medium carbon steel it recommended 2000rpm and > 2ipm. That was a disaster. It started off cutting a very heavy chip > (10-20 thou thick) got about 1/3 into my 0.5” dia piece and then > pushed it’s way to destroying the insert and bending the opening on > the tool that holds the insert. What is the opposite of “just in > time”? Well, that is when I hit estop. Luckily I have two ends on > this cutoff tool so I have one more chance :-) > > I know I need to cut off as close to the spindle as possible. I know > that cutting fluid is good thing, though I don’t have flood so will > just be spraying or dripping something on it. But what would be good > F&S for doing this? A “machinist” recommended 600rpm and 0.6ipm > using his rule-of-thumb machining formula…? > > Also, I believe I can do CSS but don’t really know anything about that > yet, was just trying to do basic things first but if css would be > better…Any advice would be welcome. > > -Tom CSS is Constant Surface Speed. But you knew that Tom. A very nice idea but I find it is not overly useful for driving a cutoff blade as it runs my spindle out of rpms long before the job is done. Drive redesign is in the planning stage. And, my cutoff blade is steel, tapered profile. Because the side/corners dull with the amount of feed I can use with a puny powered spindle, I wrote a routine that cuts a couple thoiu, backs off, move half the blade sideways, then cuts about 4 thou, wobbling back and forth as it advances. This cuts me a slot wide enough that the blade doesn't bind in the slot even though I can see it bending sideways, but its a slow process if the work is over .5" in diameter. And I still have to stop and sharpen the blade several times. But it works well even in non-hardened A2. What I need to learn next, is how to properly heat treat/harden the A2 stuff I make. ;) > > ---------------------------------------------------------------------- >-------- Don't Limit Your Business. Reach for the Cloud. > GigeNET's Cloud Solutions provide you with the tools and support that > you need to offload your IT needs and focus on growing your business. > Configured For All Businesses. Start Your Cloud Today. > https://www.gigenetcloud.com/ > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users 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> ------------------------------------------------------------------------------ Don't Limit Your Business. Reach for the Cloud. GigeNET's Cloud Solutions provide you with the tools and support that you need to offload your IT needs and focus on growing your business. Configured For All Businesses. Start Your Cloud Today. https://www.gigenetcloud.com/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
