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[on:]

First a little background...
I am currently working on an extra credit project for my high school AP Physics class, that is to create a machine that can launch a balloon at my teachers truck from 60 meters away and peak arch of minimum 3 meters.  I wanted to be the first one to use any electronics.  (He said that in the 20+ years of doing this no one has introduced any electronics!)  So I naturally turned to my Arduino. Currently my plan is to use an IMU so the arduino knows the current barrel angle and then I enter the desired target distance and it does the calculation and moves the barrel.  To move the barrel accurately I wanted to use this very large stepper motor I have laying around.  I can't seem to find a data sheet on it, but the model # is: 4T5618M3008 and it is rated at 3A with 1.8 degree step.  I guess my first question really should be can this thing even move a large barrel?  And if it can how should I go about driving it?

Thank you!

[Reply #1 on:]

What is a large barrel? How is it pivoted? I think that you may need to supply more data, maybe some drawings?

[Reply #2 on:]

Even the smallest motor can move the largest load.  The pay off is TIME.  Small motors trying to move heavy objects need extensive gearing to increase the available torque, but this gearing means things move slower at the output end.  So the first thing you need to establish is the torque capability of the motor, then calculate the torque requirement of the barrel.  The ratio between the two is the MINIMUM gear ratio that you need between motor and barrel.  I'd recommend you double the gear ratio to provide allowance for the system losses.

Can you confirm the motor model.  Playing around with google I turned up Nanotec with motors of the type 5618 M 2008 and 4008

Looking at the part number it might break down as 4T = 4 coils  56 = body dimension  18 = 1.8degrees/pulse  M = metric fitting  3 = amps and 008 is possibly the output shaft diameter in mm   But that's all guesswork !!

[Reply #3 on:]

First off, thank you for your responses!  Now, I am not sure on the exact size of the barrel yet.  I haven't begun building it, but it has to launch a water balloon, so I would assume around 6" diameter. I will upload some sketches as soon as I have some. 

Jackrae, it is a Telco Intercon Motor, and after doing some more digging I found a datasheet for the series, but not the exact model #. 

http://www.telcointercon.com/uploads/downloads/pdf/Stepper%20Motor/High%20Torque%20Stepper/4T56.pdf

It looks to me that the break down goes like this: 4T = 4 Coils  56 = Case Dimensions  18 = 1.8 degree/step  M = Medium Size Length  300 = 3 Amps  8 = # of Wires

Now, I have only dealt with 4 wire motors in the past, do I have to do anything special to drive this?

Thank you!

[Reply #4 on:]

Another question, has anybody used this chip before for driving a stepper motor?

http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/DATASHEET/CD00002294.pdf

If no one has or if someone has with good results I might just have to get one and build a full drive circuit.

[Reply #5 on:]

You sure that 8 is an 8 and not a 6

[Reply #6 on:]

Yes, I am very sure.  Trust me, as soon as I found the datasheet i looked real close to make sure that the 8 was an 8 and not a 6.

[Reply #7 on:]

Then I suggest you contact the manufacturer for details of the motor drive voltage and torque on the basis that their data sheet does not shown that particular model of motor.

[Reply #8 on:]

Yeah, I will probably have to do that.  I can't remember where I got it from, so that's probably why! 

[Reply #9 on:]

The L6208 will go upto towards 3A, but only with the package with the heat-slug (power SO36) and good heatsinking - the
others will hit the thermal cut out at lower current values - but yes I've used it to drive NEMA 34 motors, it
works if you keep it cool.

[Reply #10 on:]

Ok, what about using the popular L298N?  I was thinking along the lines of using 2 or 4 in some sort of parallel mode to get high currents.  Would that work?

[Reply #11 on:]

I can't remember offhand if that chip can be paralleled (I think there was a recent post about it though, try a search),
but if so then you could up the current handling - but you'd not have the ability to use constant current drive from a
high-voltage supply (which is needed for high-speed operation).  If high-speed isn't a requirement it sounds a possible
approach (given my first comment).   [ just for completeness L6208's cannot be paralleled ]

There are higher current H-bridge modules available, such as the Pololu ones.

BTW do we know the winding resistance for the motor?