On Saturday 24 June 2017 05:20:26 andy pugh wrote: > On 24 June 2017 at 04:53, Gene Heskett <[email protected]> wrote: > > But I've no specs that give tooth height or tip radius > > profile, so the best I could do at composing a tooltype would be a > > SWAG. > > The tool table doesn't do height anyway, but you should be able to set > the included angle exactly to the correct 55 or 47.5 degrees. (or that > silly 60 degree angle that the foreigners use :-)
Uhh, Andy, as one of them foreigners, hadn't you noted that g76 for instance, defaults to assuming a 59.5 to 60 degree included angle. At least the instructions do. It's the folks with the Whitworth and such bolts that are half a bubble off to the rest of us. ;-) > It might be useful to measure the tip radius and tooth height, just to > know what thread the insert can manage. (in theory you could use the > radius number to help touching-off, touch off to the notional > perfectly-sharp dimension) Andy, I don't have a thing that could measure those angles, or the tip radii which is pretty sharp. So I attacked the tool.tbl editor, assigned a tip radius of 0.0025, and tried front and rear angles with a 60 degree separation, then found the ORIENT figure does NOT turn the tool image like it shows in the Documentation.pdf, but moves the imaginary contact point around on the radius of the tip. IMNSHO, thats a bug as it will force me to compose 8 tools just to match what I see in the pdf's. And TBT, its fairly rare that the toolpost is tightened down dead square. It may "look" square, but I wouldn't bet on it being within 5 degrees to the axis's of the machine right now. So I adjusted that for the center of the radii. So now I had a true 60 degree triangle. Next I played with a multiplier constant in the z advance calculation until it would just touch one side of the tool, in this case the advancing edge, and cut on the trailing edge as it went deeper into the thread. So next (I'm inside feeding the missus ATM) I go out and compose another tool image that is a mirror of this one and check the exterior cutting as its all in the g33wrapper.ngc to do either, with or without the taper. So back to the salt mine I guess. 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> ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
