Gregg Eshelman wrote: > > What I'm looking for is for each type of motor (AC and BLDC) is "You want at > least x watts and n amps to at least be in the same range as the old motor." > On cncdrives.com I noticed the torque values listed are different for AC and > DC motors of the same watts. > > The old motors were 5.8 amp cont, 30 amp peak. Stall torque 3NM cont. Max RPM > 2400. Max voltage 140 DC. > Now, there's an important data point missing from your original question! RPM. So, a motor of so many Watts can be wound for low-speed or high-speed operation. Belt drives have a limited ratio they can provide in one stage. So, a 3:1 or 4:1 reduction is the maximum that is practical in this case. Also, as the belt reduction increases, the motor's OWN inertia becomes dominant. That's why many machine tools run the motors 1:1 with massively oversized motors to get the required torque for acceleration. But, modern motors, especially the brushless type, have low enough rotational inertia that a 2:1 ratio will be just fine.
Anyway, you can compute the linear force a ballscrew can exert from some given motor torque, and then compute how much acceleration in G's that will give. That is a good exercise, rather than talking about motor Watts. Jon ------------------------------------------------------------------------------ Learn the latest--Visual Studio 2012, SharePoint 2013, SQL 2012, more! Discover the easy way to master current and previous Microsoft technologies and advance your career. Get an incredible 1,500+ hours of step-by-step tutorial videos with LearnDevNow. Subscribe today and save! http://pubads.g.doubleclick.net/gampad/clk?id=58041391&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
