control linear stepper actuator with NI myDAQ

[nejcmedv]

Hello,

for my experimental application i would need to control linear stepper actuator shown below : 

http://www.haydonkerk.com/LinearActuatorProducts/StepperMotorLinearActuators/LinearActuatorsHybrid/S... - CAPTIVE one

if i am not wrong i would also need this

http://www.haydonkerk.com/LinearActuatorProducts/IDEAStepperMotorDrives/tabid/285/Default.aspx 

or

http://www.haydonkerk.com/LinearActuatorProducts/Drives/tabid/70/Default.aspx

I would like to connect this stepper actuator with my NI myDAQ card. Since I have no experience with stepper motors I would need some help with that.

Best regards,

[KateB]

Yes, you need a drive, but you cannot control it with MyDAQ, since it interfaces via either 485 or USB.

[Bogatyr]

Hi Nejcmedv,

So first of all I would suggest to get familiar with the stepper motors in general and

I actually read trough this wiki link and found it quite usefull.

http://en.wikipedia.org/wiki/Stepper_motor

This type of linear motor is same as regular stepper but it only converts rotational

motion to translation by some inner gearing (or in this case the screw type of connection

where the rotor is one part (let's say nut - and your actuator the other in this case bolt. By

limiting possibility of rotational motion the parts will move appart)

There are Unipolar and Bipolar steppers and they use different type of drives. There are also

drives that can control either type of motor.

When choosing the driver be cautious not to burn either the drive or the motor. You must examine

datasheets and look at what current you expect flowing trough your motor (based on your system)

and then choose the appropriate drive.

Drives communicate in different ways - be sure to find one that suits you. If we are talking about

interfacing with MyDAQ search the drive that expetst just "plain" digital inputs. Again this can vary

based on specs. of the drive, but you'll be looking at at least one counter output (to send steps to

drive - belive me on that one - because of speed counter is much more suited for this than normal

DO). You'll also need one DO for the direction of rotation. Sometimes there will be more inputs

request that for example determine the way the drive sends steps to motor (half-stepping, double stepping,

sine, ...)

Altenativly IFF the speed of the motor is not expected to be too high you could use directly the MyDAQ to

make your own driver (providing you have time and want to do it). You'll just need 4 DO. But be aware that

this MAY DESTROY the MyDAQ so i would isolate it from the motor with Darlington transistor:

http://en.wikipedia.org/wiki/Darlington_transistor

You can find this in IC's for a negliable price, and there is a lot manuals on the internet how to do it.

Check the ULN 2803A for example as driver for unipolar motors.

For me to be more specific I'd need to know more but the point is this.

I would think of this as in following action list:

Understand application needs -> Choose the right motor (have some performance reserve but don't overkill it) -> choose the drive / interface type

Based on your time and finance there is sea of possibilities.

Regards,

B.