On Thursday 04 July 2013 08:47:15 andy pugh did opine: > On 4 July 2013 07:06, Gregg Eshelman <[email protected]> wrote: > > Why not cut involute spur gears on a 4 axis with end mills? > > It ought to work, but it is likely to be rather slow. You probably > need a rotary axis with very low backlash too. > Emphasis on very low Andy, which pretty much excludes my $110 4" from Grizzly. But nobody sells a small table with a harmonic drive at a price I can afford. Those sprockets I was making a couple years back that you did the code for (thank you for that magic), needed a .001 degree move to take up the backlash, dependent on which face of the tooth the bit was moving against. I took a stroke on the faces of the finished tooth with a smallish file in order to get the fatter teeth to enter and leave the new chain. I have since put a bigger motor on that table, milled an air groove in the mating faces and pulled the bearing up for considerable drag, intending to add air injection to float the faces during the move, but lockup tight when the air is off. But I've not found an electrically controlled valve suitable for such use, so that stage is still incomplete. My missing round tuit has contributed to the projects lethargy too. :(
> I suspect that one concern will be the required tool length/dia ratio. > (I haven't drawn any sketches yet, though) 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> Only adults have difficulty with childproof caps. A pen in the hand of this president is far more dangerous than 200 million guns in the hands of law-abiding citizens. ------------------------------------------------------------------------------ This SF.net email is sponsored by Windows: Build for Windows Store. http://p.sf.net/sfu/windows-dev2dev _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
