Tobias Gogolin wrote: > Thanks for your responses Kirk and Andy! > No, we are not planning to create a toy here and the machine wants to be > production oriented, as that is what pays for it! There will have to be > further mechanical improvements as to avoid that the Sleds could jump a > tooth on their linear gears, but the servo eliminates the potentially missed > step of a stepper at any speed. > The wish to close the loop could be interesting to be able to recognize > obstacles (current limit) or adjust speeds to machine physics without having > to manually calibrate. But its true if this is not yet implemented, I cant > promise to be the one to do it ;) > > So now I understand that if using the gecko driver I would have to also feed > the motion readout to the computer somehow in order to close the loop? > Then I think it would be better to go to some other type of interface that > can do that in one move! Anybody using these FPGA based controller cards > here? Or the pico solution, what do they do? > > Yes, that's what my Gecko Interface does. It powers the encoders from the Universal Stepper Controller board, so the encoders always are feeding position back to the USC. It makes an opto-isolated copy of the encoder A/B signals for the Gecko drive. It also senses faults of any Gecko drive and shuts them all down, lighting an LED to indicate which drive was the one that faulted. It sends an E-stop signal to the USC so that EMC knows that a fault has occurred. You can then clear the fault from EMC and it powers the Geckos back up and resets them to enabled status.
So, you can hit E-stop and then move the machine manually, then get back out of E-stop and the position is always kept track of. > Also, i know I have to call them but maybe somebody has experience for > these servo motors: *KL23-130-60 (NEMA23) dual Shaft $79.95 Skewed Rotor * > http://www.kelinginc.net/ServoMotors.html > Do i need to get the readout encoder or does it come with it? I see no > specification what kind of signal this provides! Skewed rotor refers to the > little twist in the laminate stack? I suppose this would be a brushed DC > motor? Brush-less I bet is much more expensive? > Actually, Keling has a similarly-sized, but more powerful NEMA 23 motor in the brushless configuration for $52! (without encoder) I used to sell this with a CUI AMT103 encoder, but discovered the CUI encoder had a really bad lag in responding to acceleration. I can't find a similar encoder at that price, so I had to up the price for a motor+encoder combination. My brush servo amps are $125, the brushless version is $150. These servo amps are NOT step/direction, so you use them with my Universal PWM Controller instead of a stepper controller. No need for the Gecko Interface, then. That brushless Keling motor is the KL23BLS, they only stock the largest one, and it has a 1/4" shaft on the back for the encoder. Jon ------------------------------------------------------------------------------ Get a FREE DOWNLOAD! and learn more about uberSVN rich system, user administration capabilities and model configuration. Take the hassle out of deploying and managing Subversion and the tools developers use with it. http://p.sf.net/sfu/wandisco-dev2dev _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
