5 wire Stepper motor configuration

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singhm29
 
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Re: 5 wire Stepper motor configuration

Post by singhm29 »

wow im feeling really stupid right now. For some reason I was under the impression that the arduino powersupply from the usb was running through the motorsheild and supplying enough voltage to the stepper (yes that completely makes no sense). So now rereading the motorsheild infosheet on how to power the motors I just tried hooking up the same powersupply that I used earlier to get the working CW sequence. Its rated at 12.5V and 150mA and I decided to remove the jumper cable as instructed on the site connecting the wallwart to the ext power block but BANNED the green led of the motorsheild turned on at a very dim green and then turned off and i felt the wallwart and l293 chip and both were fairly warm. Comments and suggestions?

singhm29
 
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Re: 5 wire Stepper motor configuration

Post by singhm29 »

wow even weirder I had thought I killed my motorshield somehow as putting on the jumper and using USB power alone was still resulting ina super dim motorsheild light. Strangely even thoough the wallwart was disconnected from the wall only when I started unscrewing the wires from the ext power block did the LED brightness start getting brighter until finally being completely bright again...

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adafruit_support_bill
 
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Re: 5 wire Stepper motor configuration

Post by adafruit_support_bill »

Is that AC or DC? Your manual stepping test would have worked with either, but the H-bridges need DC only.

And 150 mA is not really enough current for anything but the smallest of steppers (like you might find in an old disk drive).

singhm29
 
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Re: 5 wire Stepper motor configuration

Post by singhm29 »

That would be DC. Yea the extremely low current rating of the wallwart would explain why the led would be dim and then turn off and the fact that the wallwart was getting hot from supplying over its rated current right? I tried looking around for how much current a wallwart should have that is used with the arduino uno and found it quite difficult. People say what the voltage should be around but not the current and I guess im afraid of supplying to much current but now were having problems with to little current lol. Do you think you could give me a ballpark figure for how much the motorsheild needs and the uno? Or how you went about figuring that information out so I dont have to keep bothering people about it? Cant wait to test it out with a proper power supply!

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adafruit_support_bill
 
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Re: 5 wire Stepper motor configuration

Post by adafruit_support_bill »

The Arduino itself will happly run on less than 100 mA. What else you connect to it determines how big a supply you will need.
In the case of the motor shield, the motors you are driving will be the determining factor.

To run one of those Jameco motors, you should plan on about 700 mA.
For various reasons, we recommend separate supplies for the motors and the Arduino.

singhm29
 
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Re: 5 wire Stepper motor configuration

Post by singhm29 »

Yes I have read about the problems that can occur from using the same source. Would there be a problem with supplying to much current to the motorsheild? Or is it usually undercurrent that can cause problems? Im kind of hoping that the original motor that this entire post is based on wasnt working due to the insufficient voltage supply so for that motor type it says it needs something like 170mA (assuming we have the 12V) model. So the 12V 500mA would definitely be sufficient right?

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adafruit_support_bill
 
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Re: 5 wire Stepper motor configuration

Post by adafruit_support_bill »

Would there be a problem with supplying to much current to the motorsheild?
Generally, no. Assuming that the voltage is appropriate, the motor will draw only what it needs. The only real danger of higher current supplies is that they can do more damage if something is wired wrong or shorted out.
Or is it usually undercurrent that can cause problems?
An under-sized supply will typically not be able to maintain the rated voltage into the load. Depending on how far the voltage sags, the motor will run with less torque, or sometimes not at all.

singhm29
 
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Re: 5 wire Stepper motor configuration

Post by singhm29 »

I see and by voltage sagging it refers to when the voltage drops as more current is supplied. Again thanks for all the tidbits of information hopefully we have reached the end of this long stepper motor battle.

singhm29
 
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Re: 5 wire Stepper motor configuration

Post by singhm29 »

alright the war does not seem to be over...I ended up powering the motorsheild off a 12V 2A wallplug I had lying around and the arduino seperately off of USB power. So single coil dont work it steps forward 2 back 1 and keeps doing that but suprisingly double coil actually works except for the fact that both of the following commands result in movement in the exact same direction.


motor.step(100, FORWARD, DOUBLE);
motor.step(100, BACKWARD, DOUBLE);



Interleaved also does not work it does the same thing as single coil exication. Does this have something todo with it being a four phase stepper?

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adafruit_support_bill
 
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Re: 5 wire Stepper motor configuration

Post by adafruit_support_bill »

It sounds like the coils are getting energized enough to step. You probably just have a coil reversed. Try swapping pairs of leads until you find a combination that steps consistently.

singhm29
 
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Re: 5 wire Stepper motor configuration

Post by singhm29 »

So i found a configuration that works finally! But the problem is it gets insanely hot, is this normal? The wallplug powering the motorsheild is 2A which is really high i know but I figured like you explained that the motorsheild would only draw as much as it needed and no more. Should I lower the wallwart to something like 1A to reduce the heat problem?

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adafruit_support_bill
 
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Re: 5 wire Stepper motor configuration

Post by adafruit_support_bill »

Which motors are you using now? Do you have a link to the data sheet? Look for the ambient operating range and the temperature rise specs.

Steppers do tend to run hot. Some are rated for over 100C.

singhm29
 
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Re: 5 wire Stepper motor configuration

Post by singhm29 »

Using the same one as I started the post with actually, the datasheet is here doesnt seem to say anything about heat could i put a heatsink or something on it?
http://www.mitsumi.co.jp/latest/Catalog ... sp_7_e.pdf

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adafruit_support_bill
 
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Re: 5 wire Stepper motor configuration

Post by adafruit_support_bill »

The "Insulation class" is the key here. Class E insulation is rated for a 65 degree C temperature rise with a max temperature of 120C. That's pretty hot! Nevertheless, keeping it cooler will extend the life of the motor (and keep you from burning your fingers!)

You might be able to find a heat-sink to fit it. A fan would also help.

singhm29
 
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Re: 5 wire Stepper motor configuration

Post by singhm29 »

Ah i see, wowwwwwww i could cook eggs on that thing lol. Awesome ill look into that then but will likely replace the motor in the future but at least now i can continue developing my code! Another little question what exactly does motor.release() do? And whats the range of motor.setSpeed? I tried searching for an explanation of these functions but they were pretty limited on the arduino main page

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