[K_G_B]

Hi guys,
I'm looking at building an OX CNC but wanted to upgrade stepper motors a bit.
Looking at 269oz.in Nema23 - Nema 23 CNC Stepper Motor 2.8A 1.9Nm(269oz.in) 23HS30-2804S - US$
to drive x, y & z
I thought to place a heavier nema23 on z as well since I'm planning on getting one of those 6Kg (13pounds) chinese spindles later on.

That particular stepper motor is a 2.8A, 5.4mH (inductance).
If I follow Gecko website info about amps and max voltage I get:
(3*2.8A)*0.67=5.628A required for all 3 steppers.

max voltage= sqr root of Inductance * 32
max voltage= 74.3v

Now, I can't find any chopper drivers reasonably priced that can handle 5.5A in total, or 2.6A per axis as well as handle max voltage of 74.3v.
Am I just finding ****ty stepper motors or am I trying to use larger Nema23 steppers which DIY scene has no drivers for?

Any input is appreciated.
Id most drives accept around 25v that means my Nema23 are going top be almost useless since theyneed 74v, which means I need weaker steppers, a lot weaker.

[Bubba]

Regular Gecko drives (20x variety) are rated to max 80V and 7 amps if I remember correctly!

I have some original 201's on my router running NEMA23s with no problems.

[K_G_B]

Yes they are very nice but also very expensive for my first project.
I'd rather get something cheaper and more open source if possible and once I get my basics straight then I can start improving on equipment.

If you guys think they would be my only good option for driving Nema23 at max voltage then Ill save up and buy them.

[ger21]

Am I just finding ****ty stepper motors or am I trying to use larger Nema23 steppers which DIY scene has no drivers for?

When you try to spend as little as possible, you'll rarely end up with a perfectly matched set of components at thelowest possible price.

Just find some motors with a lower inductance, and use a Gecko G540 and 48V power supply. While that still be more than you were planning on spending, it'll probably give nearly double the performance.
NEMA23 282oz/in 3A Stepper Motor

If you do get that Chinese spindle down the road, I think you'll find that it's much too heavy for the lightweight OX machine, and you'll see considerable flexing in the gantry.

[K_G_B]

Alright, I'm convinced, I'll get the G540. It was just my first CNC project and I was afraid I'd screw something up, but by the looks of it, G540 will not let me screw up most of it by automatically switching off if there are problems.

One thing I keep finding at a couple of stores is soldered potentiometers on cables from steppers to G540, like this:
EZ-G540 - Set of 4 - Soigeneris.com

Isn't G540, like any stepper driver supposed to regulate current on its own? If so why the manual limiting in stepper cables?

P.S. that is a crazy good Nema23 with almost unbelievable Inductance value Thank you, good find.

[ger21]

Isn't G540, like any stepper driver supposed to regulate current on its own? If so why the manual limiting in stepper cables?

Those aren't limiting the current. They are on a different pin, and tell the G540 what the motors rated current is.