came across this with 5 stepper motors and a driver board im looking for a way to control 4 steppers at the same time using arduino not a cnc but a robotic arm per-say..
i cant find info on this guys board if any one thinks there's a better easier way to run my steppers with the arduino please point me to it almost done building the arm with no way to move or dive it with out doing 4 steps here and 20 steps there individually
They look like NEMA 17 size steppers, and given that they're short, they won't be that strong. NEMA 17 steppers can be purchased new for under $20/ea.
I can pretty much guarantee that if you attempted to use these for a robotic arm that it would not work. Motors used for robotic arms require a lot of gear reduction to give them the torque they need to move the arm. For commercial robotic arms it's that gear reduction that makes robotic arms cost so much -- not the motors themselves.
If you look at the questions on that auction you'll see that nobody knows how to use the driver.
maybe i miss read it ... i thought it said that the seller does not know how to use the driver.. not that no one knows how to use the driver ...
thank you for the in put i do think im going to pass even tho the price seems right
sorry cell phone wont let me quote stuff but yeah im not making a huge arm only about 20 to 24 inch reach on my work bench alumanim constrution eact arm langth is about 8.OZ so gear reduction to give me about 2 -5 pounds of force would be fine i only need an extra hand with my soldering pcb bords
will these drivers step my motors at the same time to have fluid like motion of to axies at once i bought the af motor shild and it takes up alot of my atmega 2560 pins and does not seem to have a way to runn 2 steppers at the same time . so i was thinking maybe the auction above with the spark fun drivers would be able to run my steppers off one arduino i would be fine if could figuer out how to use my dc motors with ir encoders on them but the code seems compacated to run them .
Look at this thread - I have worked on the code to use a ATtiny2313 as a controller for a Step/Direction stepper controller. Use the 2313 to control a H-Bridge for a bipolar driver, or 4 MOSFETs for a unipolar driver - Single stepping, or Wave stepping or Half stepping.
I have 1 functioning, have a few other projects that took over so I haven't got the 4 units built that I am still planning on building.
the ATtiny2313 - ATTINY2313-20PU-ND at Digikey - sells for $2.67 and then the cost of whatever driver you need.
Programming chips is really quite easy once you get over the initial nervousness.
WOW you read my mind !!!!
this was my back up plan if i couldn't buy a driver that will work with my application...
so many questions so littile time !
so how are you commanding the attiny that you got to work ? with another arduino...........?
thats what i was gonna try a attiny running a code to read a pwm command that would be sent by like an arduino uno and step that meany times but i havent got that far i enjoy the engineering side with mechanical movements but that requires some electronics know how these days
thanks for working on this idea before me !! you findings should make my life a lil less stress full awesome work guy !
I would definitely do the torque/speed calculations for your arm before choosing your motors and only then deciding on an appropriate driver. If you want 2 lbs of force at the end of a a 24" lever it will require 760 oz-in of torque so you would need a rather hefty motor. If you used 4-1 gearing I would think a 200 oz-in motor would be enough so you should probably be looking for drives that can output at least 2 amps.
Having said all that, have you considered hobby servos for your arm? Most of the hobby robotic arms I've seen use them, the advantage being you only need a power source and a signal, no driver required. Things are simplified mechanically also with the gearing built in and with a hub allowing easy attachment.