On 02/28/2014 12:31 AM, Gene Heskett wrote: > This latter is a common lament from all of us table > toppers I imagine. I am amazed that they put in something > that can only turn 2500 revs, then we put motors on it > that are fully capable of moving fast enough to stall said > motor even when its in low gear, and that of coarse leaves > you with a pair of carbide pieces worth 10 to 20 bucks, to > be dropped in the recycled carbide container. That was why > I was asking a few weeks back about those 12k rpm R8 > spindles on fleabay. The Taig "CNC" mill has a 10K RPM belt drive scheme. I think it would be fairly easy to get higher speeds on many of the tabletop machines with minimal work. > You folks shot me down saying the run out was probably > well over 3 or 4 thou. These little table toppers really > ought to have spindles capable of marching that 1/8" 2 > flute carbide bit, plowing a slot .06125" deep in an alu > workpiece (with mist lube & prayers that its hard alu so > it cuts clean & doesn't gum fill the bit=instant quiet > little "tink" The trick to aluminum is to take shallow cuts at a high feedrate, and repeat with enough passes to get to the depth you need. The high feedrate sees to it that the aluminum doesn't get hot enough to soften. And, 90 F is enough to soften it!
I had an accident many years ago with a 1/8" piece of 2024 aluminum and a 1/8" solid carbide tool that gave me some ideas of what they can take. I forgot to set the Z first, and the tool plunged full-depth into the plate and started running across it at 40 IPM. It was cutting JUST FINE, depth = tool diameter, and full width in the aluminum! It was only when I hit E-stop that the cutter broke! This was at 2720 RPM (fastest my mill goes without overspeeding the motor.) Jon ------------------------------------------------------------------------------ Flow-based real-time traffic analytics software. Cisco certified tool. Monitor traffic, SLAs, QoS, Medianet, WAAS etc. with NetFlow Analyzer Customize your own dashboards, set traffic alerts and generate reports. Network behavioral analysis & security monitoring. All-in-one tool. http://pubads.g.doubleclick.net/gampad/clk?id=126839071&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
