Home | Member Profile

News - New Product Friday: Scopi… | about 3 weeks ago

Yup, and NEMA-17s work quite well with the Big Easy Driver (cheaper than the L6470, but not as awesome) and surprisingly well with the original Easy Driver.

News - According to Pete: April … | about 2 months ago

Pete, as always, interesting, useful, and more than a little bit humorous. Thanks for doing these videos.

And I would love to hear more about motors- specifically, more ‘rules of thumb’ or gut-feels about how to drive various kinds of motors, especially larger ones, under microcontroller control. I’ve always wondered about the differences between the various types of motors too, theoretically and practically.

Product ROB-10735 | about 3 months ago

Yes, if you’re pulling that kind of power, it will get plenty hot. Don’t lick it for too long. You can use little heatsinks, or fans, to cool the driver, motor, or both. Don’t worry about damaging the driver chip – it is protected against over temp. Just worry about melting nearby plastic and burning fingers. Are you sure you really need that much torque? If not, a smaller motor, lower current adjust, or lower input voltage will all help to reduce the temp.

The noise is due to the chopping circuit oscillating near the audible range. As you found, changing the motor current can sometimes help eliminate the noise. Also, changing motors (even the same size/voltage, but a different model, or from a different manufacturer) can have a big effect too.

Product ROB-10735 | about 3 months ago

Yup, you got it right. They will default to HIGH if you leave them disconnected, so you can then pull them to ground by just connecting them with a wire to ground. You can then use the table in the driver data sheet to see what microstep value you’ll get with any combination of MS1, MS2 and MS3

Product ROB-09238 | about 4 months ago

No need – there are several libraries out there for stepper motors. The one I use a lot, and really like (and supports Easy Driver and Big Easy Driver out of the box) is AccelStepper (http://www.open.com.au/mikem/arduino/AccelStepper/). It now even works with PIC32 based chipKIT boards and the UBW32. See my video for an example: http://www.youtube.com/watch?v=7Ga6RMYwuQI

*Brian

News - How Low Can You Go? | about 4 months ago

This is a great first version. May I suggest a real 100W laser, with slight fog effect for visibility. You’ll have a lot more fun if you can singe body parts as you go under. Would make for a lot better drinking game too. And if done on roller-skates – man, you’d have a killer.

News - According to Pete - Febru… | about 4 months ago

Super awesome excellent video, as always Pete. Love the style, honesty, and pragmatism. Teach us more!

Product ROB-10735 | about 4 months ago

You can e-mail me directly at brian_schmalz at yahoo d0t com if you want. In answer to your question, you’ll need to give the BED more voltage than 5V if you want it to run. At least 7V for a minimum probably, but 12V is much better.

*Brian

Product ROB-10267 | about 4 months ago

Yes, it should work. However, your coil resistance (66 ohms) is so high that the EasyDriver will not be able to chop (the coil resistance will self-limit the current), so you won’t get any microsteps. The best you’ll be able to do is half-step. But I don’t think it will damage the motor, even if it does end up getting a bit more than 90mA.

Product ROB-10267 | about 4 months ago

Nope, not at all. Your motor will not achieve maximum torque or speed, but you’ll probably be surprised how well it will run even on 750mA/phase.

Also note that the BigEasyDriver (also sold by SparkFun) will have no problem running your motor at its max rated current.

*Brian