Gecko 202, these motors?

[stdly]

After lots of looking I am hoping to use gecko's G202 drives on my mini mill.
Will these motors be ok for the Gecko?

I have 2 X,Y Axis
NEMA 23
1.8
425 oz-in
4 WIRES
VOLTS = 4
AMPS = 2.8
OHMS = 1.42
I don't know how to figure out the Inductance on this Nema 23.

and 1 Z Axis
NEMA 34
1.8
637 oz-in
4 WIRES
INDUCTION = 3.5
AMPS = 5.5
OHMS = 0.42
I don't know how to figure out the voltage on this Nema 34.

Resistors?

I have a 42 VDC @ 15 amp and a 42 VDC @ 10 amp will one of these do all three axis or will I need both supplies.

I will be using CNC4PC’s Mini Power Supply, Charge Pump and Parallel Port Interface Card.

Any help would be less blue smoke and I will do all the actual physical labor. :-)

Steve

[ger21]

I don't know how to figure out inductance, but voltage = amps x ohms,
or 3.5 x .42 = 1.47V
Using G202's, the 15amp supply should be fine for all 3.

[stdly]

Thanks for the volts.

As I understand the motor supply voltage should be no more than 20 * so if that motor is 1.47vdcX20=29.4vdc does this mean that I have to use a lower voltage for that motor. The G202 also wants 24VDC min.

Originally Posted by ger21 I don't know how to figure out inductance, but voltage = amps x ohms, or 3.5 x .42 = 1.47V Using G202's, the 15amp supply should be fine for all 3.

[stdly]

After looking around on a chart and with a claculator it looks like volt are figured out by this formula I think.
V=A * Ohms
My motor would be 5.5*.042=2.31VDC
2.31 x 20 = 46.2 max vdc and for best result they say 10 X 2.31VDC = 23.1 vdc. So my 42 VDC would be pushing it for this motor I guess?

[ger21]

I made a typo and put 3.5 instead of 5.5, so you're right, 2.3V.

Gecko recommends 3-25 times the rated voltage. The higher the voltage, the hotter the motor will run. I'd think you should be OK with 42V, but if you're worried, try to find a motor with a slightly higher voltage rating.

Read Geckos stepper motor info here:
http://www.geckodrive.com/photos/Step_motor_basics.pdf

[stdly]

Hey you set me on the right track. Thanks!

2.31*25=57.75
Worth a try, it might run a bit hot at 42VDC from what I have read here.

The other 2 motors are 4VDC so they will run well at 42VDC.

I still have to figure out the resistors for the Gecko's, for each of these motor types, anyone?

Originally Posted by ger21 I made a typo and put 3.5 instead of 5.5, so you're right, 2.3V. Gecko recommends 3-25 times the rated voltage. The higher the voltage, the hotter the motor will run. I'd think you should be OK with 42V, but if you're worried, try to find a motor with a slightly higher voltage rating. Read Geckos stepper motor info here: http://www.geckodrive.com/photos/Step_motor_basics.pdf

[stdly]

I found this formula but don't understand it completely.

Ohms = 47,000 * I / (7 - I)
Ohms = 47,000 * 4 / (7 -4)
Ohms = 188,000 / 3Ohms = 62,667

[stdly]

Ok I found that post again and it looks like I used the amp rating to figure out the resistor. I in the formula was what I could not figure out.

Can anyone confirm this

4 wire 2.8 amp motor
47000*2.8 = 131,600
7-2.8 = 4.2
131600/4.2 = 31,333ohms

4 wire 5.5 amp motor
47000*5.5 = 258,500
7-5.5 = 1.5
258,000/1.5 = 172,000 ohms

[stdly]

This was confirmed by Mariss for all us who did not know for sure.

Originally Posted by stdly Ok I found that post again and it looks like I used the amp rating to figure out the resistor. I in the formula was what I could not figure out. Can anyone confirm this 4 wire 2.8 amp motor 47000*2.8 = 131,600 7-2.8 = 4.2 131600/4.2 = 31,333ohms 4 wire 5.5 amp motor 47000*5.5 = 258,500 7-5.5 = 1.5 258,000/1.5 = 172,000 ohms