Need a kick in the right direction.

[misasi]

Hi guys im trying to sort out what would be the ideal setup for me. I will be building my cnc out of 8020 very shortly but im undecided on what to use for my electronics. I want to be able to cnc aluminum but i do not know what torque spec steppers to buy. Then to go with that what driver to get. I was looking at the gecko products and they looks nice but i would love to assemble a DIY kit. Are there even any half decent DIY kits that micro step?

[Crevice Reamer]

Hi misasi. Welcome to the Zone!

Yes, but we need more info: What is cutting area of your router? What type of axis drive are you using: Ball screws, rack & pinion, acme? (what thread?) What are you using for a spindle motor & how much does it weigh? What is gantry weight?

CR.

[misasi]

I dont have the exact details but i know I will have a cutting area of at least 36" x 25". As for the axis drive im having a really hard time with trying to decided. I don't know what would be best for my application. I had thought rack and pinion but now im trying to debate if im going to shell out the money for a ball and screw setup. For the spindle i was going to start small with a dremel and then eventually move over to a router.

[Crevice Reamer]

Here's my recommendation for your electronics:

$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.

[misasi]

Thanks for the quick reply... Do you think i will regret going with only 380oz steppers? Ive never actually built a cnc before so i don't know exactly how much i need. However I did have my eye on that drive. I do like how its also 4 axis. The reason i am concerned about the 380oz steppers is that they are pretty much at the upper limit that the G540 can handle.

[Crevice Reamer]

Originally Posted by misasi Thanks for the quick reply... Do you think i will regret going with only 380oz steppers? Ive never actually built a cnc before so i don't know exactly how much i need. However I did have my eye on that drive. I do like how its also 4 axis. The reason i am concerned about the 380oz steppers is that they are pretty much at the upper limit that the G540 can handle.

So you think they might be too big? No way. The 381s are as close to the perfect motor for the G540 yet found. They should be perfect for you whichever way you drive your axes. If they run too fast for you, you can always slow them down in Mach3.

Check out how this bad boy runs with LESS efficient (387 oz) motors than the new 381:

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

CR.

[misasi]

I just don't want them to be too weak. I'd rather pickup a better drive and stepper if the 540 will only do a mediocure job because of being under powered. And by under powered I mean the steppers and drive combo not being sufficient to cut aluminum. However if the 540 will do it im happy because that setup is a steal and i like how everything is integrated into 1 unit.

Sorry for my newbish questions but I have a few more:
What are the SS relays for? Is it just for pump and spindle power? Is there any reason to avoid mechanical Relays? And lastly for the current sense resistors is there any reason i should not use potentiometers?