John: Thank you for the rapid response. You've confirmed my thinking, thank you.
On Sunday August 5 2007 4:04 pm, John Kasunich wrote: > > The usual recommendation for supply voltage is 10 to 25 times the motor > rating. Using a 36V supply for 3.7V motors is about 9.7 times rating. > That is on the low end, and will show up as limited high speed torque. I agree. The driver kits are inexpensive and work OK but for these motors I really need higher voltage drivers. They did come as a set though. > Increasing the ratio will help at very low speeds. But it will might > get worse, not better. I've been thinking the corner of the curve, where the torque starts to roll over and down, would be at a higher rpm. I've been thinking it would be above normal steel machining feeds, at least for drilling. Is it low enough to affect torque and these low speeds? > Yes. The copper loss in the motor (heating) is proportional to current > squared. You are running at 83.6% of current - squaring that says you > are producing only 69% of the heat that the motors would produce at > their rated current. So they will run cool. I missed the squared term in my thinking. I'll up the current and see if they get hotter. I think I'll upgrade for the rapid speed improvement just the same. -- Hugh Currin Klamath Falls, OR USA ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
