Look what I found on AliExpress
What do y’all think? I haven’t purchased it. It seems like the torque is low, but all of the reviews are positive. One guy said he was going to replace all of his closed loop 2Nm Steppers with these after he bought one.
http://s.aliexpress.com/Jfi2YnyY
Feels like one of those upgrades I would take on personally… One that I “need” even though I have not yet got my machine up and running yet, let alone pushed it to the point that it is hitting some limit that warrants an upgrade… Just relating it to the way I think.
I’ve seen a lot of people who say good things about integrated servos. I’d love to try one some day, but I’m probably only going to get one at first.
@John_Bump well, I’d love to get a clearpath servo, but those are a minimum of $257 and this one is only $94 + $30 shipping. That’s what jumped out at me.
I think you probably still have a lot you can get out of your present steppers. Optimizing those you might be happy with them. What voltage are you running at now? Even a few more volts can make a tremendous difference on the low end with stepper motors. Like say going from 24V to 32V. That would be huge. A new PSU would be cheaper than one servo motor too.
@Paul_Frederick Good point. I’ve got to get my gecko driver checked out first.
@George_Allen if you go with all Gecko drives you can run those up to 80V. But even 48V would probably be good enough. I wouldn’t push TB6600s much past 32V input. That is due to them having regulators on board that can’t handle much more than that. Usually the filter caps on them are not rated too high either. Plus the drive ICs themselves are probably counterfeit too.
@Paul_Frederick no, those tb6600s can’t go really that much above 24v. They can get hot as an oven. I have one 48v PSU running the x&z axes right now and I had to lower the current on the X as the motor was getting hot.
I can’t afford another gecko driver, they are about $100 a pop.
You can get a Leadshine hybrid stepper/servo at 0.9Nm for only $15 more (that one, by comparison, is <0.6Nm) or their 2.0Nm unit for another US$15: https://www.aliexpress.com/item/Leadshine-NEMA23-Closed-loop-integrated-machine-ISS57-20-or-IES2320-2N-m-with-1000-encoder-servo/1000005237919.html
Best of both worlds? The jury seems to be in that hybrid closed-loop steppers are, in our implementations, as effective as a servo at significant cost saving.
@Mike_Thornbury Yes, I’ve been thinking about the lead shine drivers. I think they can be used with servos too, if needed.
@George_Allen not a driver, George - that’s a closed-loop stepper - hybrid between a stepper and a servo. It can’t adjust power like a servo can, but gives most of the advantages of a servo in positional accuracy.
@George_Allen I run TB6600s the V1.2 model boards. They work fine at 32V. That’s these https://www.aliexpress.com/item/TB6600-4-5A-stepper-motor-driver-board-single-axis-controller/32471854330.html
Good to get recommended units as there are a lot of bad clone TB chips out there.
Some can’t take anywhere near the rated amps.
As to heat: there are strategies with most drivers to mitigate power at low speed - Gecko certainly does, not sure about TB6600 - I use nearly all TI chips at home and they do.
Add a heatsink to the stepper case. You can knock off nearly all the excess heat - the gearbox/motor mount is a poor conductor.
@Mike_Thornbury I just run the TB6600s I have at 2 or 3 amps depending on what motor I am driving. Amps is pretty misleading with stepper drives too. It is the Watts they can handle that counts.
@Paul_Frederick hey Paul,
What all do I have to do to set up EMC2 and LinuxCNC? I may try to set it up, if it’s not too much of a hassle. It’s more likely that I explore it after I get everything on the machine set up and working the way I like it. I’ve got everything working, but there are still some things I need to tighten and clean up. One thing is my estop. My BOB requires me to set it at active high. But, something is backwards because the switch has to be depressed in order to run the machine. If you release the button it stops the machine. I tried switching the wires and changing to active low, but neither worked. I have 3 limit switches set up at this time. I also am still working on the X axis. I also need to wire the spindle to the controller so I can turn it on and off and adjust the rpms. I also ordered some more pieces (DIN rails & terminal blocks that attach to the rails/ I also already had a wire track) so that I can remake a larger controller box.
After installing the inductive sensors with all the necessary modifications, they seem to work well and appear reliable.
It seems the more I work with the machine, the quicker and easier it is to diagnose and troubleshoot many of the electrical issues, as I was able to correct the issues with the limit switches and issues with one of my motors.
I’m pretty weak on Linux. Other than playing with a raspberrypi, I’ve had no experience with the operating system. I know nothing about Python, though I’ve downloaded several things off of GitHub and worked with several different controllers and arduinos.
@Paul_Frederick I have one of these coming
@George_Allen LinuxCNC comes in a package with a custom preconfigured Linux distribution. So you do not need to know anything about Linux. You boot the image and it runs. But I guess I could find the URL where to get the image for you. This page can tell you more than I can http://linuxcnc.org/docs/html/getting-started/getting-linuxcnc.html
Joining the forum there is a good idea too. You can also get real time help in the LinuxCNC IRC channel on freenode. Sometimes I even hang out in there.
I don’t know beans about Python either. Which is why I can’t get my CAM software working on my new PC. It seems like the devs on that project don’t know Python very well themselves. Or they’d update their software for newer systems.
@Paul_Frederick Great! Thanks for the info!