New Part Day: ST’s New 3D Printer Motor Driver

ST has released a new evaluation board for a stepper motor driver. It’ll plug right into your 3D printer, and if you’re looking for a chip to build a cheap 3D printer controller board around, this might be the one.

We’ve come a long way in the field of stepper motor drivers in just a few short years. The first popular driver for RepRap electronics was ‘the Pololu’, a stepper motor carrier board using Allegro’s A4988 driver. If you had a big heat sink, this driver could deliver 2 A per coil, operated between 8 and 35 V, and had microstep resolution down to 1/16th. Was it the best stepper driver around? No, but it was cheap, it was everywhere, and RAMPS, the popular RepRap control electronics picked up on its pinout and accidentally created a standard. The DRV8825 motor driver from TI followed next, with microstepping down to 1/32nd, a little more current per coil, and arguably a better thermal design.

Then the wave of Trinamic drivers happened. The Trinamic TMC2100 was a silent stepper motor driver when running a motor at medium or low speeds. With this driver, you could run a motor more efficiently, which means the motor doesn’t get as hot. There are diagnostics via SPI. Tom liked it, and now in every Prusa i3, you’ll find a bunch of Trinamic drivers.

ST’s new offering, the STSPIN820, doesn’t have the fancy-schmancy features the Trinamic driver does, but the chip itself is fantastically cheap, at about 1/5th the price of a Trinamic driver. As far as feature set, you should probably look at this new chip as an upgrade to the A4988, with much higher microstepping and slightly higher current handling.

If you’d like to experiment with the evaluation module, you can grab one from an ST distributor; at the time of this writing, there were seventeen of these modules available worldwide. If you’d just like to play with the STSPIN820 motor driver chip, ten thousand are available between Mouser and Digikey, starting at $2.97 in quantity one. If someone could tell electronics manufacturers to build more than a dozen evaluation boards at a time, that would be great.

21 thoughts on “New Part Day: ST’s New 3D Printer Motor Driver

  1. I wouldn’t worry about that scant dozen boards. If these ST drivers are any good, we’ll be able to bucketloads from AliExpress or BangGood as soon as they copy the eval board.

      1. Absolutely. They have a lot of collaboration between the companies on china, so one (or more) will probably pruduce 10s of thousands of boards with bulk price (real) chips, and they will distribute those to a myriad of small sellers.

  2. The rapid drop in stepper driver prices (and size!) and increase in performance is one of those consistent sources of amazement for me.

    I remember when the Allegro A3982 based RepRap Stepper Driver 2.3 was new on the scene and only like $30 a pop, instead of the $50 something to put together an L297+L298 based board, and it was amazing. Now I have a bag of A4988 stepsticks that were like a buck a piece that I threw into an order just because, and some far fancier drivers in projects, most of which cot less for a 3-axis set than a single driver would have in 2008.

    1. I hear you! I can remember the evening (out drinking beer with some friends from the hackerspace, actually) when I first heard about the A4988 — I didn’t believe that it was running with as little heatsinking as it does. We bought a few to upgrade our 3D printer (Darwin, oh my) for only like $15/per? and it was soooo awesome.

      Kids these days and their stepsticks…

      No, reallly. It’s awesome.

  3. Umm, Digikey lists these driver boards at $9.18 each, and of course no stock. For comparison a TMC2130 board is $12.73 and readily available. For the extra $3.55 I would spring for the Trinamic drivers that offer a ton more options with SPI control.

  4. Thanks for posting, I’m interested :-) Data sheet for the chip can be found here:-
    https://www.st.com/content/st_com/en/products/motor-drivers/stepper-motor-drivers/stspin820.html
    With DS12312 specifying motor connections missing from the eval board data, there some chip internal schema. Oddly user manual UM2434 has contents at end whilst others have as normal at front of course not that important, let’s hope no other things back to front though…

  5. The ST stepper is cheap an compact. I personally find it uninspiring. It is slightly better than the A4988 and not cheaper. So if you want low price the A4988 would be a better choice. If you can spare some extra $, then the TMC2130 offers more convenience and pizazz.

    The have the L6470, which is more interesting. Close to Trinamic in terms of features with 3A current handling.

    1. I’d agree. There isn’t really much other than the Microstepping here. I’m not sure on whether that’s actually the biggest necessity here. The Trinamics are much more interesting due to their smart features. This guy here looks rather like a 4498v2 for more money.

  6. Trinamic drivers offer features other than silent operation. resistance feedback to replace endstop switches, belt skip detection. combined with devent drivers and software can recover prints and make 3D printing in general more plug and play. 3D printers are still far form being unattended one touch devices like inkjet printers, but they are well on their way compared to even a few years ago.

  7. Does anyone happen to have recommended motors for CNC applications? I tried to find the ones used on the Pursa printers but they don’t seem to say and all the pictures have labels over them.

  8. I’m still waiting for one of these boards to come with abillity for optionall sensored feedback. Ustepper and mechaduino are great but to have that build in hardware would be awesome.

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