[don_don]

I have just purchased the G540 4 axis package from Keling and not sure what size resisters I should be using. I have read the user manual and through the forums here and still not confident I understand.

G540 4 axis package (One G540 + Four
KL23H284-35-4B (1/4” Dual shaft with a flat) 387 oz-in + one KL-600-
48 48V/12.5A 115V /230Vpower supply)

http://www.kelinginc.net/KL23H284-35-4B.pdf (motor spec sheet)

also what is a good online electronics store to purchase these from and also limit switches / home switches / e-stop

[Richards]

The KL23H284-35-4B stepper motor is rated at 3.5A, so, with the G540, you would use a 3.5K resistor (1/8W to 1/2W). Radio Shack has 3.3K 1/4W resistors, which would work to get you started.

www.automationdirect.com sells switches, proximity sensors, contactors, relays, etc. www.jameco.com and www.digikey.com sell electronic parts, such as resistors, chips, etc.

[Crevice Reamer]

Digikey has a 3.48K 1/4 Watt resistor that is perfect. Ten cents.


http://dkc1.digikey.com/us/en/pdf/Current.html

http://search.digikey.com/scripts/Dk...sistor&stock=1

CR.

[don_don]

Thanks for the help. I ordered the resisters/limit switches/home switches on wednesday.
recieved my G540 4 axis kit from Keling yesturday and . Today was the first day I brought my machine home after 3 yrs working on it (very exciting). This is my first cnc so still trying to figure out what to do tomorrow.

[Crevice Reamer]

That's a nice looking machine don! Good work! I bet you can't wait to make some sawdust.

CR.

[fretsman]

Don, just wanted to comment on your tank of a machine there. Looks built VERY well and would love to see more pics of it if you have them-

What are your travels?

Thanks,
Dave

[don_don]

table is about 32 by 15. I will post more pics here as I complete project. Received my resisters from digikey today but was unable to find 22/4 shielded wire or I would have started to connect controller/motors.

[Crevice Reamer]

table is about 32 by 15. I will post more pics here as I complete project. Received my resisters from digikey today but was unable to find 22/4 shielded wire or I would have started to connect controller/motors.

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.

http://cgi.ebay.com/Servo-Motor-Wire...3286.m20.l1116

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 on or off.

These inexpensive relays are very good :

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

You will also need an estop switch. This one from Keling only costs 10 bucks and works fine:

http://kelinginc.net/CNCPackage.html

On that same page Is a DB25 serial connector which you may need.

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.

[LaserImage]

I have just purchased the G540 4 axis package from Keling and not sure what size resisters I should be using.

It would seem to me that Keling would be providing great customer service if they provided the resistors with their "package". They don't cost much and if they provided them to their customers, it would save a lot of time and trouble trying to figure out what is needed and where to get it...

Gary

[autocadplease]

I just bought the same package too. Do you really need shielded wire?

"Radio Shack has 3.3K 1/4W resistors, which would work to get you started."
When so say get you started, can they be used permanently? Or does the 0.2K make a difference?

[LaserImage]

I just bought the same package too. Do you really need shielded wire?

I didn't use it and I have not having any problems at all. Not to say you won't, or it that it is a good idea, just that mine seems fine.

"Radio Shack has 3.3K 1/4W resistors, which would work to get you started."
When so say get you started, can they be used permanently? Or does the 0.2K make a difference?

3.3K vs 3.5K will reduce the amount of current you have going to the motors - by about 6%. Figure out what a 6% reduction in speed will be and decide if you need that extra bit - probably not. So, yes it will make a difference but how important is it?

Gary

[Crevice Reamer]

Shielded wire is BEST, but optional on motor cables. Shielded wire is NECESSARY for home/limit switches.

There is a slight loss of performance when you limit the Amperage. I prefer to wait and get the proper resistor size, just because I KNOW that once I solder those in and mount the connectors--I'm NOT going to unsolder and replace them.

So, at least for ME, it's permanent.

CR.

[Crevice Reamer]

If you are running 3.5A motors, You can safely leave out the resistors for awhile. The motors will run a little hotter though because without resistors the idle current limiting is turned off.

CR.

[autocadplease]

Thanks everyone. I appreciate the quick replies.

[Richards]

For all practical purposes, a 3.3K resistor will work perfectly with a 3.5A drive. Yes, you will lose 0.2A, but are you really running your machine that hard?

You can buy DB-9M connectors in bulk from Jameco for less than fifty-cents each in quantities as low as ten units. They offer 100 connectors for $39. Buy a bunch and experiment a little. There is plenty of room for two resistors, one on each pin. A 3.3K + a 220 ohm makes 3.5K. If you don't want to have even 20ohms too much resistance, just use a 3.3K + a 180 ohm resistor or a 150 ohm. To me, that's splitting hairs, but it can be done - easily.

[autocadplease]

Sorry for these Newb questions:

Do you solder the resistor directly on the DB9 connector? Or use wire leads?

I have 16ga/4 shieled wire - is that to big?

[LaserImage]

Sory for this Newb question, but do you solder the resistor directly on the DB9 connector? Or use wire leads?

Mine are soldered directly into the cups on the db9.

I used 16ga wire but according to Mariss I could have used a lot thinner. I will use 18 or 20 on my next machine - the voltage drop on that short length is really not worth worrying about.

Gary

[Crevice Reamer]

Well, you COULD extend the leads. There is plenty of room in the long shell, and that WOULD make it easier to replace the resistors later.

All in all though, the way you did it is the right way. Why introduce a couple more possible failure joints.

CR.