Confused with the specification on a old stepper motor (Y163-4).

Hi All,

I am a little confused about controlling a two stepper (x and y) cnc.

The motors are where i am losing the plot a bit due to them being pretty old school. They are Astrosyn Y163-4 motors and the data sheet can be found here

The motors say they are 5v 1A but the data sheet seems to say they are 1A at 34v…

On Farnell the product info says “The Y163 is a 1A/5V Stepper Motor with 1.8° stepping angle, 5R resistance, 9.5mH inductance. This stepper motor requires external drivers to control them, with components including a power supply, logic sequencer and switching components.”

This has me more than a little confused!

I was hoping to run these with an Uno (GRBL), running from a 24v supply and DM556 drivers. Am I barking up the wrong tree?

Any help is appreciated,

Thanks

Mort

How many wires are there on your motor? The datasheet seems to cover a few different versions.

If it is a bipolar motor (4 wires connected in pairs to two coils) then an A4988 or DRV8825 driver will be suitable. Make sure that the current limit is set to 1 amp on the driver in order to protect the motor.

You can safely ignore the 5volts provided you limit the current. I suggest using a 12v or 18v power supply.

...R
Stepper Motor Basics
Simple Stepper Code

Hi Robin2,

The motors are 8 wire, as i read the data sheet it suggests connecting the wires in different configurations to achieve different outcomes! But i may be WAY off base on that one!

Cheers,

Craig

I hadn't read it carefully - I thought it was showing connections for 3 different motor variants.

I reckon either of the bipolar wiring arrangements will do. If the resistance for a single coil is 5 ohms (you can check with your multimeter) then with the series connections the combined resistance will be 10 ohms and with the parallel connections it will be 2.5 ohms.

I think (emphasis on "think") if you use the parallel connections you need a motor driver that can supply 2 amps (as the coils are in parallel, I think each can take an amp) and if so the DRV8825 (which is a little more powerful than the A4988) could not provide that amount of current - you would need a driver that can provide up to 3 amps to give some headroom.

On the other hand if you use the series connections then the current limit will definitely be 1 amp and the A4988 would be perfectly capable.

The advantage of the parallel connections (and the lower combined coil resistance) is that it will perform better at higher speeds for a given motor supply current.

...R

Hi Robin2,

Firstly, thanks for the reply and the help.

So, here is my thinking (and, as i said, i could be totally off base here!)

If I manage to figure out the wire colours (obviously thay are not the same as the data sheet, cos that would be far to easy!)

I can connect it up in series and that will give me a total resistance of 10 Ohms per pair of coils.

Given V=IxR that gives each coil 2.4 Amps (Voltage being 24v)

Now the windings are rated at only 1Amp so i guess there would be a puff of smoke and my motors go hot and wrong for ever…?

I could limit the amps through the driver but the lowest setting is 1.4 amps on the dip switches so will that fry what i have?

I have paired up the wires by testing them but I have no idea which coil is which as well!

BTW this is an old cnc3 teaching machine that i bought to see if i could get it up and running again, these motors are not what i would have gone for given the choice!

Ruitmexi:
Given V=IxR that gives each coil 2.4 Amps (Voltage being 24v)

Now the windings are rated at only 1Amp so i guess there would be a puff of smoke and my motors go hot and wrong for ever…?

Yes

I could limit the amps through the driver but the lowest setting is 1.4 amps on the dip switches so will that fry what i have?

What driver are you referring to? Please post a link to its datasheet.

I suspect 1.4 amps would be too much - but the motor won’t expire instantly. Just monitor the temperature. If you have a high current driver why not use the parallel connection system?

Neither the A4988 nor the DRV8825 modules have dip switches to select the current limit - they have a small preset potentiometer.

…R

Hi Robin2,

I am having a little trouble finding a data sheet for the driver. It is a dm556 from banggood here

I will have to just bite the bullet and try them, and hope they will run without to much of an issue. I do tend to overthink these things...

Cheers,

Mort

That driver is overkill for a 1 amp motor.

…R

1A only needs a DRV8825 module to drive, assuming windings in series. If wired in parallel a heavier duty driver is needed.

Figuring out the wiring of an 8 wire motor is tricky. glue a long pointer onto the shaft and use a battery of a few volts across each winding in turn. The two matching coils for one phase will hold the pointer in the same position when powered in the same sense, and the other two will find a different position 1.8 degrees different.

Swapping polarity of a winding will give 2 steps movement, 3.6 degrees.

Once you have figured out the paring and polarity of the windings connect each set in series in the same sense. You now have a bipolar 4 wire motor. Check that each pair now still functions to move the pointer and hold the motor position (if you connect in reverse they will cancel each other).

[ note that I said use a battery as it wont be damaged by inductive kick-back - don't touch the wires during these tests because inductive kickback will hurt ]