More questions on wiring. :)

[bkboggy]

Now, I apologize for being stupid and slow, and asking a ton of questions about the same thing. However, I'm so new at this that I don't even know much about electrical stuff.

CR (a fella with a ton of great info ) mentioned that for limit switches I should have shielded wire. I am guessing that is to eliminate any interference? Or am I wrong?

I have been looking around for shielded wires and I can't find any in any stores (OSH, Home Depot, Lowes, auto stores, Radio Shack). Some of them carry Cat5 and 6 coaxial shielded cables. They're not cheap at all... let me tell you that. I have about 50 feet of shielded stepper cables that I've ordered off eBay, however, it has 4 wires within it and it would seem like a waste connecting that to limit switches. Are those coaxial cables my only choice available?

Question #2: Do I simply take the shield strands and solder them to pins of the connector on the driver side?

Question #3: Do I need shielded wire to connect my power supply to G540? Do I need shielded wire to connect my power supply to EStop switch?


Those are the questions I have right now.....


-BK

[BobF]

I bought some alarm wire at HD. I bought 500' when I put in the alarm system and had some left. Its 4 conductor shielded, but smaller gauge than what I used for steppers. I think you can buy by the foot as well, but the whole spool wasn't that much.
The shield is usually grounded, and only on one end. I ground it at the controller end.
Power supply should not need shielded.

Read this post from CR. Lots of preanswered questions.

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

[Jack000]

I got my shielded wire from a local electronics shop (rpelectronics in vancouver). Pretty cheap stuff, it was about 50 cents a foot.

the power supply, drives etc should all be enclosed in a control box. The control box should be lined in a conductive, grounded material to shield everything inside. The shielding from the wires and control box lining should be grounded to the earth pin from the outlet.

[Crevice Reamer]

Originally Posted by bkboggy Now, I apologize for being stupid and slow, and asking a ton of questions about the same thing. However, I'm so new at this that I don't even know much about electrical stuff. CR (a fella with a ton of great info ) mentioned that for limit switches I should have shielded wire. I am guessing that is to eliminate any interference? Or am I wrong?

Yes! Homes/Limits are very susceptible to it. Then what happens is you get false switch triggers in the middle of a job.

I have been looking around for shielded wires and I can't find any in any stores (OSH, Home Depot, Lowes, auto stores, Radio Shack). Some of them carry Cat5 and 6 coaxial shielded cables. They're not cheap at all... let me tell you that. I have about 50 feet of shielded stepper cables that I've ordered off eBay, however, it has 4 wires within it and it would seem like a waste connecting that to limit switches. Are those coaxial cables my only choice available?

I use THIS wire for motors AND switches:


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

Yes, sometimes it's wasted, but You can run both X and Y homes with one cable and shielded twisted pair wire is almost bulletproof.

Question #2: Do I simply take the shield strands and solder them to pins of the connector on the driver side?

Yes! Proper shielded twisted pair wire has a bare drain wire that is connected to shield. For motor cables, connect this to either pin 2, 3 or 4 in the G540 DB9 connector. For Homes/Limits (Or OTHER drivers) connect drain to ground that leads back to PSU NEGATIVE--Or to PSU negative terminal.

Question #3: Do I need shielded wire to connect my power supply to G540? Do I need shielded wire to connect my power supply to EStop switch?

No shielded wire is needed for any PSU connections. But power supply wire should be at least 18 AWG and not more than 18 inches long. Use two different colors so as not to mix them up. Connecting power in reverse polarity can kill your drive.

CR.

[bkboggy]

Originally Posted by Jack000 I got my shielded wire from a local electronics shop (rpelectronics in vancouver). Pretty cheap stuff, it was about 50 cents a foot. the power supply, drives etc should all be enclosed in a control box. The control box should be lined in a conductive, grounded material to shield everything inside. The shielding from the wires and control box lining should be grounded to the earth pin from the outlet.

Good thing that I bought a huge (only $26.99 and I'll post pics later in my CNC thread) electronic enclosure from OSH. It's sweet. I do not know if it's lined with anything.... but it's metal, so it is conductive. Not sure what makes something grounded.... (yeah... I'm probably dumb). Now, I'm not sure what the earth pin on outlet is to tell you the truth.



BobF -- thanks, I'll take a look at HD again. If I don't find anything I will have a chance of taking look at electronic surplus store in Riverside (those guys are not open on weekends and that's the only time I'm there every two weeks, but next Friday I will have off so I'll check it out).


CR:

What about paired one (8451 on the pdf catalog of the 2nd link you've mentioned) instead of the double paired? I am not sure how I would be able to run 4 limit switches with 1 cable (cut it and join with makeshift intersections?).

You've mentioned that for limit/home switches I should connect the drain wire to the PSU negative. The home/limit switches do not connect to the PSU at all, so how would I manage that? Get an extra unshielded wire and solder it to the drain wire and then connect it to the negative of the PSU?

Yeah, I was looking for some 14-16awg wire at OSH that would be perfect for PSU and EStop.


-BK


P.S. Found enclosure on Lowe's website, since OSH website doesn't show much: http://www.lowes.com/lowes/lkn?actio...00C&lpage=none

[bkboggy]

What about this?

http://cgi.ebay.com/ws/eBayISAPI.dll...DLVI%26ps%3D54


Dirt cheap shipping and I already have the stepper motor wire from him (looks well made).


And this would probably work if I want to use one cable to spit with 4 wires? http://cgi.ebay.com/ws/eBayISAPI.dll...DLVI%26ps%3D54 However, I would still have to waste a little bit in order to keep them shielded.... would still be less if I would go individually full length, right? I could also use dean's connectors or any other kind of connectors for this (dean's are expensive though).

[Jack000]

electrical outlets usually have 3 pins - the hot wire, return path, and ground (or earth). The earth pin is electrically connected to a long pole buried underground, and serves as a reference point of earth's electrical potential. It's basically an infinite current sink.

To be "really" grounded, your grounds should be connected to the earth pin. The cases of your power supplies should be earth grounded, so just make electrical contact with it (mounting screws should do it) and you're set!

[BobF]

"What about paired one (8451 on the pdf catalog of the 2nd link you've mentioned) instead of the double paired? I am not sure how I would be able to run 4 limit switches with 1 cable (cut it and join with makeshift intersections?)."

You wire all the limit switches in series on one cable. You use normally closed switches so that you have a complete circuit when no limit has triggered a switch. This way if you trigger any switch, you know you are at the limit. The nice thing about this setup, if the machine, or you, or the work happens to cut the wire, your limit triggers. Now you know you need to fix the wire and don't find out it is broken with a big crash when you really needed the limit switch. You can also use the same switches for home in some cases.

[bkboggy]

Found paired shielded wire at HD as you've suggested, BobF. I'll use that since it's only like 20 cents per foot. My Kelings power supply didn't come with any instructions or anything.... There is no AC plug in it, so I'm going to have to do some research on that thing.

[Crevice Reamer]

What Keling PSU do you have?

CR

[bkboggy]

KL-350-48 and this is the only diagram I could find.... http://www.kelinginc.net/PowerSupplyDiagram.pdf which tells me... nothing since I have no clue what it means.

[Crevice Reamer]

Okay!

L= LINE and is the power wire or small slot in receptacle. Small plug blade.
N= Neutral and is the large slot in receptacle. Large plug blade.
G= Ground and is the green wire that connects to ground hole in receptacle. Rouind plug post.

When you wire up your steppers, you will want to wire each one directly from the power supply. So there are 3 POS terminals (V+) and 3 Neg terminals. (V-) One POS wire goes from each V+ terminal to each stepper and one Neg wire goes from each V- terminal to each stepper. If you have more than 3 steppers than some terminals have to double up.

VAdj is a little pot for a small screwdriver that adjusts the Voltage. On mine, I set it to 52V no-load, and that equals 50V when steppers are on.

CR.