Silent stepping for bigger stepper motors - Page 1
Forum section: electronics / general

author: Infraviolet
author_rank: Super Contributor
timestamp: August 30, 2024, 05:52:36 pm
content: The trinamic silent stepper driver range are really popular for "typical" and smaller" stepper motors, NEMA17 and less with phase currents of 2A and less. But what are my options for use with larger (albeit not huge) steppers, NEMA23 4A-5A per phase sort of thing? I know that microstepping drivers, little black box units with TB6600 or similar inside plus some support circuitry and differential receiving on their step and direction input signal pns, are popular but I don't particularly want the torque reduction that moving to more microsteps entails. As it is, I've tried a 4A NEMA23 in full step mode and the vibrations were horrifying, particularly at speeds around half a revolution per second (100 steps/second), though when the motor was sat atop a slab of polystyrene rather than sitting on the desk directly the sound was much less as other items on the desk didn't end up resonating in time with the motor. Can anyone recommend equivalent, to the ubiquitous TB6600 black box modules, constant current chopper type drivers optimised for smooth and pretty quiet full stepping with motors larger than the popular trinamic chips can support?Thanks

author: Doctorandus_P
author_rank: Super Contributor
timestamp: August 30, 2024, 06:26:41 pm
content: First, the TB6600 is one of the cheapest, but also one of the worst stepper motor drivers. It's one of the noisiest (mechanical noise, probably electrical noise to) and it also is plagued relatively often with resonance issues.Second, you do loose a bit of torque with microstepping, but not the huge amount that used to be repeated and parroted from a very old paper and misquoted. In total you loose around 20% torque with microstepping, regardless of how many microsteps you take.But for the essence: For Nema23 and bigger, the closed loop stepper motors are the way to go. These use the (microstepping) input only as an input to what the motor position should be, and the generate nearly sinusoidal currents to control the motor phases. They use the feedback to both compensate for lost steps, and for FOC or something similar. This makes them run much smoother and resonances are not common. I once had a CNC job on my small machine, it was to make some 40 or so small round wooden disks out of a single sheet. And on my small machine I made an error on the setup and a part of the program could not be reached. The machine simply ran into mechanical end stops (I have no end switches). Due to the closed loop motors a bunch of the round disks just had a flat side, but otherwise they were still usable for my purpose.And if you want to bring it to the next level, then you can add vibration dampeners to the motor mounts. This has a similar effect as laying the motor on a piece of styrofoam instead of laying it directly on your desk.If you are interested in tinkering, you can look into the (now pretty old) projects such as mechaduino and the ananas stepper. You can now also buy similar motors with integrated drivers from the chines. For example from JMC.I've bought a few different brands (or clones, you never know with the chinese) and they all behave similarly. Sometimes I think about building a test jig for both Nema23 and Nema34, similar tohttps://hackaday.com/2024/07/02/putting-some-numbers-on-your-nemas/While searching for the above link, I also bumped into a link that shows the internals of those integrated motor & driver combinations:https://hackaday.com/2023/03/08/stepper-killer-killer-killed-repair-attempted/It's an interesting article to read. It shows a factor of 2 or 3 difference between similarly sized Nema17 motors. I guess the quality difference between Nema23 motors is similarly big.and last: Trinamic also has some drivers (with external FET's) that are big enough for Nema23. Most Nema23 motors only need 3A or so. But there are "low inductance" motors that can run at higher speeds and these also need more current.

author: thm_w
author_rank: Super Contributor
timestamp: August 30, 2024, 09:10:23 pm
content: Closed loop does not guarantee FOC, you can have a closed loop stepper that uses full steps. Probably many of them are though, and would be the best solution.TMC4671 is one of the trinamic external FET ICs, but I don't see any simple nema23 options available.Leadshine should have some stuff if you want an external drive:https://mecheltron.com/en/product/leadshine-em503https://mecheltron.com/en/product/em542sThey also have closed loop drives (HBS57)