[absolutepoker01]

Hello, ive been thinking about getting the Nema 23 3 axis package from Keling, but the one with 425 oz-in steppers and 24 V power supply (dont know the amps, guess its 8.3A), so heres my question, the motors are rated 2.8 A/phase (im i wrong with this?) in bipolar parallel, so does this means i need a 2x3x2.8=16.8A power supply? the number 2 is because the motor has 2 phases, and the 3 cause there are 3 motors, im i wrong in my math?

Anyway thanks for the help!.

[Crevice Reamer]

Hi AP. Welcome to the Zone!

Please read all of this. With more understanding you can make a wiser choice:

http://www.cnczone.com/forums/showthread.php?t=78713.#3

What machine are you planning to power with these motors?

CR.

[absolutepoker01]

Hi AP. Welcome to the Zone!

Please read all of this. With more understanding you can make a wiser choice:

http://www.cnczone.com/forums/showthread.php?t=78713.#3

What machine are you planning to power with these motors?

CR.

Thanks CR!, wow you did a really informative post there, glad you showed me!

ok im a little confused with the motor specifications, the one im gonna buy is a 425 oz-in rated at 2.8A in bipolar parallel (http://www.kelinginc.net/KL23H286-20-8B.pdf), but in other datasheets that i have seen its says per phase, so the rated current is the max of the motor or you have to double it up for the 2 phases? so with your formula it would be 2.8x3x2x.60=10.08A?

thanks.

[absolutepoker01]

Oh by the way im planing on running the JGRO router design, i know the motors maybe are just to powerfull, but maybe in the future ill upgrade my machine.

[Crevice Reamer]

No, you don't double the phase Amps. 2.8 + 2.8 +2.8 = 8.4 x .67 = 5.62A.

Please don't be sucked into the "More is better" newbie mistake. The idea is to get the power AND fast RPMs for quick rapids. Believe me, you will WANT fast rapids on a router. To get the max power out of your 425s, you will need an 84V PSU. Electronics that can handle 80V are expensive. The Keling "kits" are not necessarily the best for an application.

Sq Rt of 6.8 mH = 2.6076. Times 32= 83.5V for best motor speed.

Here's what I recommend:

$289 G540 http://kelinginc.net/GeckorDriver.html
$147 3 $49 KL23H2100-35-4B 381 oz motors for X, Y & Z
$060 One KL-350-48 48V/7.3A power supply.
$010 Estop switch
$007 3 Home switches
$009 Straight thru parallel computer cable.
-----
$522 Total electronics cost.

$149 Mach3 cost with above purchase.

$671 To spend at Keling. http://kelinginc.net/

This most likely will be the best electronics for your router.

Start by reading this:

http://www.cnczone.com/forums/showthread.php?t=76865.#3

You may also need some other stuff:

You can use THIS wire for motor cables and home/limit switches. Ground the drain wire ONLY at the driver end. (Pins 3,4,5 for motors, PSU Ground for homes/limits)

http://cgi.ebay.com/Stepper-Motor-Wi...item45ecb75966

It also comes in 100 ft roll.

BELDEN 8723-100 STEPPER MOTOR CABLE WIRE

$32 http://www.fullcompass.com/product/305455.html 3 WK SHP

$33? http://www.jameco.com/Jameco/catalogs/c273/P101.pdf

$38 http://www.mcmelectronics.com/produc...100-/36F1033WA

$39 http://www.jameco.com/webapp/wcs/sto...oductId=734180

$40 http://www.markertek.com/Product.asp...&utm_campaign=

$44 http://www.alliedelec.com/Search/Pro...SC=8723+060100

EUROPE http://www.cable-world.co.uk/online.htm


You won't need any db9 motor connectors with the G540, as they come WITH it. The G540 also has circuitry for simple spindle speed control and outputs for dc relays to turn coolant pump (Or router motor) on or off.

These inexpensive relays are very good :

https://www.surpluscenter.com/item.a...tname=electric

You will need one of THESE 1/4 Watt 3.48K resistors for each 381 or 387:

3.48KXBK-ND

Or one of THESE 1/4 W 2.8K resistors for each 270:

2.80KXBK-ND

They only come in a pack of five, so about $1 for 10. With shipping it's about $3.50

http://digikey.com/

Or, in Canada:

http://digikey.ca/

You will also need an estop switch, Home/limit switches, Helical couplings and a 6 foot "straight thru parallel port cable. These are all available from Keling:

http://kelinginc.net/CNCPackage.html

The G540 is so small that many are mounting theirs INSIDE the computer case.

Camtronics has a case MADE for the G540:

http://s120220635.onlinehome.us/stepper-components.asp

CR.

[absolutepoker01]

Thank you CR for your advice, i was considering the geckos, i know they may be better quality, they just look really nice!, but im a little short on my budget, so i was thinking on a cheaper one, but as you said on your post it may be better to spend a little more instead of replacing a part, so i think ill go with the geckos, but to compensate a smaller stepper, what do u think?

(3)Stepper 185oz, 1.9V 3A 83,85
Gecko Driver 289
Power supply 48V 7.3A 59,95
Breakboard 25,49

total.................................$458.29 + shipping

The power supply ampers and volts are within the range of the recomendations based on the steppers specs.

By the way the gecko driver always work with a 1/10 microstep, isnt there like switches to change the microsteps? i think a read the driver run at full step on higher speeds to raise torque, but its automatically done by the driver.

Thanks. AP

[absolutepoker01]

Sorry i think theres a mistake, with the gecko i dont need breakout board right? so it would be $25.49 less, total $432.8

[Crevice Reamer]

Hi AP. The motors I recommended are the best to use with G540. They will move your axes properly. Trying to go cheaper is false economy because you will have much less performance, Then you will have to spend MORE money to replace the poor performing motors. Save up the cash and get the full package, or put the $120 savings on Breakout board to use.

Yes, I said $120, because the G540 is an advanced BOB with speed control built in, and the BOB PSU built in AND it comes with motor connectors.

This $6000 commercial router uses a G540 and 387 motors. (which are not as efficient as the ones that I have recommended for you to use):

http://www.cnczone.com/forums/showthread.php?t=77409

CR.

[absolutepoker01]

Thanks CR youve been really helpfull, ive learned a lot with your posts, thanks again, ill keep updated.

AP.