[forgetcolor]

total newb question here. looking at steppers for a jgro. i see that some come in single shaft and others in double shaft. i presume the double shaft means there's a shaft on both ends of the motor (which are really just two ends of the same shaft or at least functionally appear to be so). what would this shaft on the other end be used for? i can't see a need for this in my application.

thanks!

[Crevice Reamer]

Hi forgetcolor.

Some would say the double shaft is to install hand wheels for manual milling. This is not actually very feasible. Theoretically, the extra shaft can be used to mount an encoder for closed loop control. This IS feasible, but seldom done. Open loop control can be quite useful and much less expensive. If Closed loop control is really necessary--Better to just spend the bucks and go full servo.

I find THREE reasons to go double shaft:

1. It IS handy to have a manual wheel attached during initial setup.

2. It is also handy to be able to chuck the back shaft into a drill for set up and aligning axes.

3. Sometimes the double shaft motors, because they are most popular, are less expensive.

CR.

[forgetcolor]

CR,

Thanks very much. That helps me understand it. I can definitely see the utility of your three reasons.

fg

[Crevice Reamer]

mostly stock jgro, 1/2"-10 5-start.G540
Keling 3.5A 387 oz. in. steppers for X,Y,Z
Keling 48v/12.5A power supply

This should be a good combination for you, although for fastest rapids I would go with the Keling 5010 PSU.

You will 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) It 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 :

http://www.surpluscenter.com/item.as...tname=electric

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

3.48KXBK-ND

They only come in a pack of five. With shipping it's about $2.50

http://digikey.com/

You will also need an estop switch, Home/limit switches, (Maybe 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.

[forgetcolor]

This should be a good combination for you, although for fastest rapids I would go with the Keling 5010 PSU.

cool, will do.

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) It comes in 100 ft roll.

'drain wire'? You mean the ground? The shield?

These inexpensive relays are very good :

http://www.surpluscenter.com/item.as...tname=electric

Unfortunately your link got truncated. Can you try again or give me the item #?

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

Where do you typically wire this in? Right inside the DB9 connector? Or somewhere in whatever case you put the G540 in (e.g. on the wires as they come out of the cable)?

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

Do I need limit switches or are home switches enough? Also, is a 'straight through' parallel cable the same as a printer cable?

Interesting on the helical couplings. I was planning on going with couplers from dumpstercnc, but will check those out.

Thanks so much for the details CR!

fg

[Crevice Reamer]

Sorry the relay link didn't work. Here it is again:

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

CR.