[Redline]

I am now running the stepperworld FET-3 controller with a 12v @ 13Amp computer power supply with 1.5 ohm 50watt power resistors.I just bought a Lambda Power Supply model # FS-600A048 it is 48v @ 13Amps.My question is what power resistor (ohm / watt) should I use with the new 48v power supply(Lambda Power Supply)? The motors are 4.5v 1.4amp steppers.

[ViperTX]

You should limit the current to each of the stepper phases. R= V/I 48/1.4 = 34.4 ohms....at least 100 watt resistor....I bet that will be expensive...you don't mention how you'll wire this, but the phase pairs will need their own resistors (minimum of 2 resistors per motor).

[HobbyCNC]

I am now running the stepperworld FET-3 controller with a 12v @ 13Amp computer power supply with 1.5 ohm 50watt power resistors.I just bought a Lambda Power Supply model # FS-600A048 it is 48v @ 13Amps.My question is what power resistor (ohm / watt) should I use with the new 48v power supply(Lambda Power Supply)? The motors are 4.5v 1.4amp steppers.

Can the driver board accept 48VDC???

Dave

[Redline]

Thae board will handle 50 volts DC.I now have the centers wired together going through 1 single 1.5ohm 50watt resistor.12volts 12amps.Is there a better solution to pick up speed using this power supply.With the FET3 I can only get 11ipm with the 12volt power supply.Is there somthing else better that I could easily swap boards and not mess with the motors and such.

[HobbyCNC]

Thae board will handle 50 volts DC.I now have the centers wired together going through 1 single 1.5ohm 50watt resistor.12volts 12amps.Is there a better solution to pick up speed using this power supply.With the FET3 I can only get 11ipm with the 12volt power supply.Is there somthing else better that I could easily swap boards and not mess with the motors and such.

The spec sheet says 35V continous and 50V at start up.

Dave Rigotti
www.hobbycnc.com

[ViperTX]

What are you using for a leadscrew??

[Redline]

Stainless all-thread.

[Halfnutz]

Arent those Lambda's switching supplies?

[ViperTX]

Redline....meaning a stainless threaded rod with how many threads to the cm....this is most likely where you'll get the most improvement...unless you get some massive steppers instead.

[ger21]

The best option would be to get either the HobbyCNC or Xylotex Unipolar Chopper boards. You'll have to solder them yourself, but they're under $100. The 48V supply won't work, though. You'll want to use 24V-36V.

[Halfnutz]

Wont the switching type power supplies conflict with the drivers? I dont think that the Lambda is a simple un-regulated supply. I was told that the curent regulating circuitry in that type of supply will cause conflicts with the driver. In other words the driver is trying to regulate the current with a PWM circuit and the power supply is also trying to maintain a constant current to the motor and problems occur. Am I wrong about this?

[ger21]

I have a Xylotex that works fine with a switcher. Xylotex even sells and recommends switchers. I think the low current draw makes it OK to use them, where Gecko's can draw much more current which could cause problems. Just realised you're using it with the FET. I don't think it will hurt anything. If anything, you may just take a performance hit. I could be wrong, of course.

[DieGuy]

These guys sell a 28vdc/6amp 12v/1amp regualted toriod PSU full assembled for $49

http://www.cadcamcadcam.com/index.as...PROD&ProdID=66

I am no way affiliated, nor have I purchased one of the these, but it seems very reasonable.