Sorry to drag up this old post, but I'm new and want to do the right thing without burning my electronics up. I have 3 Astrosyn, 23LM-C708-P1, unipolar, eight wire stepper motors. I'm using the FET-3 board and purchased it with the 24V, 3A power supply and 3 Step-Syn, 103-771-18, unipolar, 5 wire, stepper motors. The Astrosyn motors are rated at 3.6V/phase and 2.4A/phase. The Step-Syn motors are rated at 24V and 0.18A. Using StepperCalc, If I put 24V as my power supply voltage, 2.4 as the Motor Current (Amps) and 3.6 as the Motor Voltage (Volts); I get 8.50 ohms as the resistor value, 48.96 watts as the minimum resistor wattage and 14.40 amps as the power supply minimum current rating. Now that I've gotten that out of the way I can finally ask some questions:
1. What are the specs on an actual resistor that will meet my needs?
2. Where can I buy them?
3. Since I have to bring all my center taps together to use the eight wire like a five wire stepper, can I use just one resistor? (I did the Stepper Calc formula using one resistor)
4. Can I keep the two coils seperated and have two center taps and wire it like a six wire stepper?
5. Is there any advantage to doing that?
6. Where can I get a 24 Volt, 14.40 Amp power supply? (It would be nice if it had a 5V, 1.5A tap to power my controller board.)
7. Since the FET-3 board can take 35V continuous and 50V start up, do you think it would hurt it to run at 36V.
8. How much difference in torque will I get if I go to 36V? (Don't need an exact number, just need to know if it's worth the risk)
9. How crappy would these motors run at 3.6V so I wouldn't need resistors at all?
Thanks for any light anyone can shed on my questions. I can't wait to get this thing running! Great site and I will be donating as soon as my router is cutting. (just in case I have to spend my last $60 on Ebay to finish it
)
Randall