old Superior electric motor getting weak

[avengine]

I have a old xy table using a Superior Electric SLO-SYN MO61-CE08 1.25v 3.8A step motor, but it is getting old and a lot of time when I drive it to cut the card, it will skip and not going back to the origin.
I want to get a new motor, but the new part is very very expensive, I want to know is there any way to buy some other parts that is pin compatible and use it. Since the software and controller is so old that if I can find something just to fix that is a lot easy. otherwise will be a big change.
any suggestion welcome.

[H500]

It should be easy to find a replacement unless they're the odd-ball 5 phase types. Do you have datasheets for the motors?

[avengine]

Yes, I find it

60mm (NEMA 23)
MO61-CE08
Connections: 8
Type: Leads
Typical time for single step (mS): 2

Unipolar configuration:
Nominal DC volts: 1.25
Rated Amp per winding:3.8
Nominal resistance per winding 25c ohms: 0.33
Nominal inductance per phase (millihenrys): 0.635
minimum holding torque: 20on:60 10on:36

Bipolar connections
Series connection
volts: 1.8
amp: 2.7
R: 0.66
L: 2.54
min holding torque
20on: 75
10on: 45
parallel connection
volts: 0.89
amp: 5.4
R: 0.165
L: 0.635
20on: 75
10on: 45

page 17
http://www.electrosales.com/warner/p...ogslosyn-c.pdf

mechanical spec on
1.656" hole to hole,

http://www.electrosales.com/warner/SuperiorM06.pdf
I guess it is using unipolar, please see what is the typical step motor I can buy to replace this.
thanks.

[H500]

As far as I can tell, they are regular motors. Just pick another Nema size 23 motor with similar specs. An exact match is not necessary.

Stepper Motor

Is your system bipolar or unipolar?

[avengine]

how to tell it is bipolar or unipolar?
I know there is a 8 pin connector go into the motor, and as you know I just want to change the 3 motors, should I pick the one around 1.2v 3.8A too?? so that the power supply can drive it right.
Sorry this is the first time I learn to do this, but I am willing to learn more, I want to build a small table after that.
thanks.

[H500]

8 wires mean that the motor can be used with both uni or bi polar drives. Your next step is to find out what type of drivers you have.

Here's everything you want to know about steppers:
Jones on Stepping Motors

Without knowing exactly what your system require, it is not easy to recommend a motor that will work for sure. But if you match the current, torque and inductance, it should work. Is the original motor much more expensive? It's the easiest way to do the repair without requiring expertise.

If you're building a new system, get a motor with more torque (270 oz-in or greater). They are slightly more expensive, but will work for real machines.

[avengine]

I get some price for the same motor is $450, to repair the motors is also $450. that mean it is $1350 to replace 3.
I would go with your suggestion to find something similar to replace it, I can see it is around $40-50 each, much more reasonable,
as you said I have to find out if it is uni or bi.
I look at the cable itself that go to the motor it is 4 wire cable to a 8 pin connectors

pin
1.........2|3...............4|5................6|7...............8
blue........white............brown.............yellow

and there is a jumper to join 1 to 2 in blue
3 to 4 in white
5 to 6 in brown
7 to 8 in yellow
that means it is only 4 wires power the motor.
what is this means.

one problem I find is that after I set the origin to 0,0

and it has the handheld controller to move the head to the far left, then I push the origin again, it suppose to go back to 0,0,
but sound like the y control has some problem, it is 1/4" to the y, x is right.
if I repeat this test, it will go more to the y for the same distance.
I will try to swap one x motor to replace the y and see what might be wrong.
From your experience, what do you suggest to try.
thanks.

[H500]

$450 is unreasonable.

4 wires on the controller means that it is bipolar.

Are you sure the motor is defective? Perhaps your slide is binding due to misalignment or the lack of lube? Perhaps the motor coupling is loose? Swapping motors is a good approach. A repeatable position error sounds odd.

What type of machine do you have? Is it an engraver?

[avengine]

it is a samplemaker, it has a motor to control the angle of the ultrasonic knife for cutting, I mostly use this to cut coroplast. the table size is 86x62". it has has pen and crease tool for making box, but cutting card board need to has a very sharp knife. not that easy.

I am not sure is the motor, belt is old or not tight enough, or the controller is bad.
BTW I know the x asix has 2 motors, one on each side, are they use one controller to drive 2 motors at the same time, the reason I ask, is that I only saw 3 motor control cards, I guess one is x, one is Y and one is for the tangential.
is this the normal way of the design?
any good link for general understanding of the router table .

[H500]

Most designs I've seen use one motor/controller per axis. Your machine is large but light duty. The design would be quite different from my mill, which has a small work area but require very high forces in order to cut metal.

[Joe S.]

. . . I guess one is x, one is Y and one is for the tangential.
is this the normal way of the design?
any good link for general understanding of the router table .

I wouldn't assume that, esp. since I can only see pictures and not the machine . . . . many of the "home built" machines use 2 motors on an axis with 2 controllers driving them. Does your "tangential" have a motor or does it only have solenoids ? Solenoids only require a power transistor to drive as there is no need to sequence them like a stepper motor does. If the tangential uses a motor then probably you are correct. Lots of motors on eBay, small nema 23 should be relatively cheap, NOT $450. I think I would do some checking, power supply under load . . .