Need Help!- Motors Won't Turn But Make Noise

[th3t1ck]

Newbie here.
I bought a kit on ebay just like this one ...
Wholesale cnc kits 3axis Nema 23 Stepper Geared Motor with 15:1 Gear Ratio252oz in/0.6A

I'm pretty sure I have it wired correctly. I have used a parport tester to send signals to the controllers and I can get the motors to make humming and squeally noises but the motors won't turn. Can someone help?

[john_100]

looking at the info for your kit
the motor has two centre tapped windings of 20 ohms
with the centre taps not connected (ie using all the windings)
with a 24v supply this gives you a maximum motor current of 24/20=1.2A
no matter what setting over 1.2A on the driver
the lowest current setting available is 1A but this drops to 60% when idle = 0.6 A


if the wiring is correct in so far one winding is connected to terminals A+ and A-
and the other to B+ and B-
try reversing the connections to one winding

John

[th3t1ck]

I did try reversing the wiring for the motors as one of my tests but still no joy. The motors still tease me with hums and squeals. I may be able to use them as a musical instrument but I would really like to use them for CNC. I appreciate you help John and I hope you don't take my attempt at humor the wrong way. I just finished drawing my wiring in Visio and have attached a jpeg of it.

[john_100]

apart from the missing direction signal to the Z axis
the diagram looks like i'd expect

just in case its some thing funny with your test signals
too narrow pulses ?

try the circuit on the Gecko website

http://www.geckodrive.com/upload/STPDIRTester.pdf

can't think of any thing more at the moment


John

[th3t1ck]

Thank you John
I noticed the Zaxis diagram error in my schematic after I posted. I have corrected that. It is wired just like the X and Y. I'll checkout the Gecko tester. Thank you for that post.

[ger21]

How fast are you trying to spin them? Geared 15:1, you won't get much speed at all out of those.
You may be trying to spin them too fast, which is causing the noises.

[Iron-Man]

Originally Posted by th3t1ck I did try reversing the wiring for the motors as one of my tests but still no joy. The motors still tease me with hums and squeals. I may be able to use them as a musical instrument but I would really like to use them for CNC. I appreciate you help John and I hope you don't take my attempt at humor the wrong way. I just finished drawing my wiring in Visio and have attached a jpeg of it.

th3t1ck

Remove power from the circuit. Disconnect the Y and Z stepper drivers, set up X only. 1st. The drives work on pulse (step) & and direction. You cannot have the direction and enable pins connected. Every time there is a change in direction (dir) your driver will be disabled. The direction pin and step pin should be connected to pins (2 & 3) for X, (4 & 5) for Y, (6 & 7) for Z. Find out which pairs of pins refer to X, Y, Z. The enable pins should be connected together, you can use either a high or low (ena+, ena-) to enable them.

2nd. Each stepper driver should be connected individually and directly to the power supply, do not daisy chain. You want each driver to see the same current.

3rd. Double check the voltage and current needed for the enable function.

4th. In summary, wire each driver directly to the power supply. The enable pins can be wired together (ena+, ena-). It looks like you have chosen (ena+) which means that (ena-) will have nothing connected to it. You only need (Puls , Dir ) connected to the BoB. In other words, if your BoB uses pins 2 and 3 for X step and direction, then pin 2 of the BoB would connect to either (Puls + or Puls-) NOT BOTH. Pin 3 direction would connect to either ( Dir+ or Dir-) NOT BOTH.

There should be 3 pairs (Puls, Dir) wires total.
Do not give up you are almost there.

Hope this helps,

Iron-Man

[john_100]

the plus and minus terminal for each input on the stepper driver
are the input L.E.D's in the opto isolators
the internal current limiting resistor will be around 220 ohm's for a 5v input

since TTL gates can sink more current than source
connecting the + inputs to the +5v is correct

I expect you need to sink about 16mA from the negative input to 0V / ground
( the maximum for a standard TTL gate )

ps to me the enable input is more of a disable input
as the motor is enabled when the led in the opto isolator is off

that is when the input is not connected
or the + terminal is at +5V and the - terminal is at logic 1 = +5v

[th3t1ck]

Not sure how fast. I'm just sending a signal using a parport tester that I found in the EMC2 wiki site under troubleshooting.

[th3t1ck]

Originally Posted by Iron-Man th3t1ck Remove power from the circuit. Disconnect the Y and Z stepper drivers, set up X only. 1st. The drives work on pulse (step) & and direction. You cannot have the direction and enable pins connected. Every time there is a change in direction (dir) your driver will be disabled. The direction pin and step pin should be connected to pins (2 & 3) for X, (4 & 5) for Y, (6 & 7) for Z. Find out which pairs of pins refer to X, Y, Z. The enable pins should be connected together, you can use either a high or low (ena+, ena-) to enable them. 2nd. Each stepper driver should be connected individually and directly to the power supply, do not daisy chain. You want each driver to see the same current. 3rd. Double check the voltage and current needed for the enable function. 4th. In summary, wire each driver directly to the power supply. The enable pins can be wired together (ena+, ena-). It looks like you have chosen (ena+) which means that (ena-) will have nothing connected to it. You only need (Puls , Dir ) connected to the BoB. In other words, if your BoB uses pins 2 and 3 for X step and direction, then pin 2 of the BoB would connect to either (Puls + or Puls-) NOT BOTH. Pin 3 direction would connect to either ( Dir+ or Dir-) NOT BOTH. There should be 3 pairs (Puls, Dir) wires total. Do not give up you are almost there. Hope this helps, Iron-Man

Thank you for the Info Iron man. I don't have them daisy changed and I am using pins 2,3 for x, 4,5 for y and 6,7 for z.

As for the enable pins they are 5v also. Should I connect them to each other (+ to -)? Is that what you mean?

[Iron-Man]

Originally Posted by th3t1ck Thank you for the Info Iron man. I don't have them daisy changed and I am using pins 2,3 for x, 4,5 for y and 6,7 for z. As for the enable pins they are 5v also. Should I connect them to each other (+ to -)? Is that what you mean?

No do not connect them (ena- to ena+) together. You only need to use 1 enable pin per stepper driver. You must decide if you want low ( ena-) or high (ena+) signal to enable the drivers. In your schematic you show 5v being used to drive the enable function. Try using (ena+) since you already have it set-up.

Iron-Man

[th3t1ck]

Hmmm. I'm still not following you Ironman, sorry. Do you mean use enable+ in my software?