there are some very nice steppers on the market that are 200 steps per revolution (400 half steps) for about $5 each, i've seen them several places. the sherline website has some good links to cnc stuff including some of the companies with these steppers. also, for dual shafted (which i'll be buying soon, i was given a proxxon mf 70) try jameco, they have some smaller dual shaft steppers, also 200 steps/revolution for about $5 ea. i'll be using the driver chips from allegro as soon as i have a board made and probably the free emc package for software, at least initially. i'd like to build a microcontroller based interface that coordinates the axes and just takes motion commands like someone else on the list mentioned, freeing the computer and allowing better control/interpolation. the nice thing about the emc package is that it runs under an rtos version of linux etc. on a pc and seems to work fairly well. there is a user and development list for emc that i've been watching, it has a few problems but handles most jobs nicely. also, the adapters for the proxxon are very simple, just a stepped piece that replaces the handles, an aluminum plate that bolts to the slide, and 4 long screws that mount the stepper to the aluminum mount, and a piece of vinyl tub for the flex coupler which is kept fairly short so there isn't much twist (hopefully). eventually i'd like to use proper flex couplers. also the proxxon's spindle runs at 5-20k rpm, i think the harbour freight unit runs much slower and the higher speed is appropriate for most materials. i'd eventually like to build or buy a larger mill/lathe. i've seen used bridgeports for $1500 (although freight would obviously add a lot to that). mostly because i'd like to eventually build firearms, i.e. i'd like to chamber barrels and possibly make my own receivers (totally legal in the u.s. as long as they aren't fully automatic etc. and aren't sold, or you can sell one year and pay the $200 tax, more than that and you do need a commercial license). one reason i'd like to build the lathe part is so that it would have a head large enough for a heavy barrel to go through for chambering, i wouldn't really need a long bed. i'm also thinking very seriously about edm, it seems to be that an edm mill would be fairly easy to make especially since you don't have to worry about the high forces during cutting and keeping everything rigid against those forces. obviously i'll be reading some edm and machine design books soon! Spehro Pefhany wrote: ------- > The couplers on my machine are torsionally rigid but tolerate a bit of > misalignment. They are machined from aluminum, as are the mounts. But they > were around $55/axis plus the motors (another $55 for double shaft motors), > which is $330.00, not including the driver board, power supply or mill. > Also the drive screws are quite small diameter, so direct drive is possible. ------- -- proof that the U.S. media is now state controlled! Ask your' local tv station why the hell they aren't airing the news any more! Our system of government requires an informed public, with their eyes open. -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body