New Machine Build- Does the G203v Driver still allow the stepper to draw current

[Spitfire]

Hi All
Can any one tell me or put me on the right track, i am using 3 G203v drivers
with two stepper motors rated at 6Volts at 1.8 amps per phase using an 18k
resistor for the current and one motor rated at 7.5volts at 2.5 amps per phase with a 36k resistor, the running voltage is 40Volts at 18 amps
My question is should the motors get hot even at idle or is that the norm!!
or am i missing some thing any suggestions would be appreciated.
Thanks Bill

[Crevice Reamer]

What motors are you running? What wiring system? (Unipolar, Bipolar Series, Bipolar parallel)

You have set the drives to send 3 amps and 2 amps. this will over-amp the 7.5 volt 2.5 motor with 3 amps, and the other 1.5 amp motors with 2 amps. This will definitely cause over heating, and will require a smaller current limit resistor.

What is the inductance rating of each motor for its wiring type?

Steppers DO get hot while sitting still--even though the 203V will cut the current to 70%. Just looking at the voltage ratings makes me think these are some large inductance motors. This would mean a lot of heat would be produced while overcoming this.

The motors should not get any hotter than 160 degrees centigrade. If you touch them with a wet finger and they sizzle--they are WAY too hot.

CR.

[Crevice Reamer]

If you call Mariss at 714-832-8874, I'm sure he would be happy to calculate the proper CL resistor values for you.

CR.

[Crevice Reamer]

BTW: These motors need a much higher voltage PSU for maximum performance. The 203V is good for 80 volts--and those motors could easily run at that, although it might be cheaper to just get some new steppers that would work well at 40 volts.

CR.

[CoAMarcus]

Here is a list of the correct current set resistor size in .5A increments from a document I made so I would not have to constantly do the formula when I talk to people on the phone. My laziness works out very well for you. ;-)

1. 1A – 7.8K
2. 1.5A – 12.8K
3. 2A – 18.8K
4. 2.5A – 26.1K
5. 3A – 35.25K
6. 3.5A – 47K
7. 4A – 62.67K
8. 4.5A – 84.6K
9. 5A – 117.5K
10. 5.5A – 172.33K
11. 6A – 282K
12. 6.5A – 611K
13. 7A – OPEN

Your current set resistors are both .5A too big for your motors, and you should definitely bring it down to the appropriate size using the formula in the manual. I have put it below to make life easy.

47 * I / (7 - I) = R Value in KOhms

Your 1.8A will need a 16K resistor and your 2.5A will need a 26.1K resistor. Remember that you can put the resistors in series to get the desired amount if you don't have the exact size hanging around. If that doesn't fix your problem, then we can go from there.

Marcus Freimanis