Hopefully you all can see this. I posted the images to Flickr. This should link to them https://www.flickr.com/photos/chris_albertson/shares/ h7h52y
There are two different types of motor. 1) Made by Electro-Craft. The label reads "Model E540" and it might be 3 to 4 pounds It has a BEI encoder on it and I have the specs for the encoder. It has 250 steps per revolution plus an index pulse. 2) Made by Tamagawa, or at least the encoder is made by them. There is no cable on the motor itself, only the encoder. This one weighs about one pound. Yes I can apply a known torque, a lever arm and a weight then see how much current it takes to just make it move. But it would be good to have some kind of starting guesses for each motor. How many amps are typically safe? I hope to use the larger motor for the Z axis of a Harbor Freight mini mill. One of the smaller motors I hope will power (via about 100:1 reduction) the first joint of a 6 DOF robot arm. This would be just a basic horizontal turn table that carries the rest of the arm. One more question. Notice in the photo of the Tamagawa motor, the one with the laminated hexagonal case, that there are FOUR power terminals at 90 degree intervals around the motor case. Two of these, 180 degrees apart as connected. Why would there be four? Thanks, Chris On Mon, Mar 6, 2017 at 3:02 AM, Charles Steinkuehler < [email protected]> wrote: > On 3/5/2017 8:22 PM, Chris Albertson wrote: > > > > Pulling the cover off an encoder I see three channels (rings) of slots > > on a thin stainless disk. One looks like it is for quadrature > > encoding and has over 1000 slots, one is an index and then there are > > some S-shape over lapsing holes. I know how to figure out encoders: > > Guess that two leads are power and look at the signals on the outers. > > But motor voltage, max current and torques? How to figure those out? > > Are they brushed DC motors, or 3-phase AC? > > If they are 2-wire DC motors, you can figure out the motor voltage by > applying a known voltage to the motor and measuring it's speed. > > Current = torque, so maximum torque will be limited by how much > current you dump into the motor, which will mostly be limited by heat. > Again you can figure out the motor's torque constant by applying a > known current and measuring the torque (or apply a known torque and > measure the current required to get the motor to move). > > You won't know the motors designed limits, but with a voltage and > current constant you can figure something reasonable and/or compare > with currently available motors of similar size. > > -- > Charles Steinkuehler > [email protected] > > -- > website: http://www.machinekit.io blog: http://blog.machinekit.io github: > https://github.com/machinekit > --- > You received this message because you are subscribed to the Google Groups > "Machinekit" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > Visit this group at https://groups.google.com/group/machinekit. > For more options, visit https://groups.google.com/d/optout. > -- Chris Albertson Redondo Beach, California -- website: http://www.machinekit.io blog: http://blog.machinekit.io github: https://github.com/machinekit --- You received this message because you are subscribed to the Google Groups "Machinekit" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. Visit this group at https://groups.google.com/group/machinekit. For more options, visit https://groups.google.com/d/optout.
