Then I have a lot more to learn :(

This is the name of the wire...... 20/12cy NuFlex 1000 Shielded Flexible Control Cable

From the applications listed....Control Systems, Machine Tool , Industrial machinery,

Factory automation and drive systems.... I was thinking that it was a cable made for our purpose...

Some thing to note :I was cutting yesterday while contracrors were servicing my shutter door, they did some welding and o boy was I pissed off. Somehow the interference from the welder throwed my project out by 10 mm on the x -axis so yes there is interference on the wires.It happened while they were welding.This morning I had to redo the project and it was perfect.

Steve, if all the reputable cable producers are talking of a bend radius nearer 10 to 20 times diameter, why would an unknown brand be able to offer 4 times?

That's the problem with today's world... Just don't know who to trust... If you read the sellers product information it seems, to the novice like myself, like this stuff is the greatest cable in the world. They cite many different manufacturing specifications and claim to meet them all...

I just did a search for the manufacture and more information... There was none to be found ... So I guess they can claim anything they want if they never have to back it up or can't even be found...

Thanks for the info Gerald :)

The guys wanting to build plasma cutters should note this.

Hennie, I don't know how much screening/shielding you used, but I won't be surprised to hear that all your cables were shielded. Welding interference is severe and it could have gotten into your system via the mains AC power supply.

If it is to good to be true it probably is. One of the guys on another forum thought he was buy all copper monster wire for his speakers. He ended buy steel coated in a copper film. Really low blow.

http://bbs.homeshopmachinist.net/showthread.php?t=40772

Gerald ,All the wires are shielded what I also pick up is that there is a lot of spikes in the electricity feed to the workshop that also has an effect on the computer and I do pick it up on the cut.I have a pumphouse close to me and 3 of the towns water pumps are there so everytime it starts up there is a spike.

Russell, I think it is hilarious that a bloke went to the cheapest store, and bought unmarked, unbranded cable and now makes a big noise that he was scammed. :D

I think the phrase "You get what you pay for" could be applied to just about any situation. :(

Gerald you should see some of the other topics. But it does show the you get what you pay for.

It is human nature to maximise their $ value & assume too much..., There are real bargain deals out there, but that would come if one dig hard enough & know your stuff deep enough... & have some risk management in place... i.e. be reasy to get scam!
There are no free lunch...

And yet there is also big money to be made in creating high markups in perceived value . . . . . some people will pay over the top prices simply because of brand name or origin. Funny how it tends to be the same people who chase top names, and then go to the other end of the scale and whine at the dollar store. :)

Exactly! :mad:

I am happy with my GWM

Kobus el-cheapo:D

To me, because the wiring seemed to be the most tedious part of my build, i wanted to make sure that the wire that i purchased was from a reputable company and that even if it cost more, the chance of product failure would be lower. Or at least i hope that it will be. I started out looking for good deals in the US on the wire, and i did actually find some but it was either heavier gauge than what was specified, or had more cores than needed ect. Then I could not find one place that had more than a couple of the wires sizes which meant that i would have had to pay multiple shipping costs, in order to get everything i needed. And i did not see any specs on the cheaper wire that i can remember so it seemed in my opinion to be kind of a roll of the dice as to what quality of product i could get by price shopping or if the wire would even meet the specs that Gerald listed. So i bit the bullet and just ordered it all from the company in Germany and paid one shipping fee and it all arrived as ordered, good quality, and I hope that the extra cost will pay off. I guess only time and use of the MM will tell.

Found a source for screened flexible cables in Argentina, now I'm trying to decide which one is the right one:
http://www.marlew.com.ar/english/pro...rcom/index.php

I called the company and they suggested the EC-ARCOMP line based on my brief description of needs, but I'll do my homework comparing their offer with LAPP and other sources listed in this thread.
Datasheet: http://www.marlew.com.ar/files/pdfs_...ples_n23en.pdf

[EDIT] prices in pesos (divide by 4 for US dollars) http://www.electrotucuman.com.ar/car...PUTAC&pagina=1

The one I need EC0408 (18 AWG x 4 + shield) is not listed but one can infer its price from the models above and below, should be around 6 pesos/meter (USD1.5)

help please
 

dear friends.

i have a question i hope im not being stupid asking.


are all the cables sheelded???or just the cables for the 4 motors?.

Cerelak,
You need shielding on your power cables to keep the noise IN and shielding on your signal wires (estop, proxy etc) to keep the noise OUT. :)

Will Cat7 network cable be usable for the motors, when they are 4 wire motors. There are 4 pairs of wires, so the wires will be used one pair pr. wire on the motor. Do you guys think that it will be usable to power the motors?

Cat-7 cable is 23 gauge. That size wire is rated to carry 0.73A (power transmission rating). Two conductors would be able to handle up to about 1.5A if each conductor carried half the load (unlikely).

Sixteen gauge conductors are rated to handle 3.7A. Thirteen gauge wire can handle 7.4A

I have never tried using Cat-x cable for motor wiring, but I could almost bet that it would be too light-weight to do the job reliably.

On my test bench, I usually use 22-gauge cable, but the lengths are never longer than six feet. For test purposes, it works. On a machine, I would use at least 18-gauge and probably 16-gauge if possible.

Mike, can you explain the power transmission rating for me? I am versed in commercial wiring. That I need to go to 13ga to run 6.3 amps is hard to understand. especially when the motor leads appear almost threadlike. Any insight would be appreciated.

Well, Chuck, you see all wires aren't created equal. If you use special gold-platinum-titanium ... Whoops, I seem to have turned into a monster.

Actually, the rated current capacity of a wire of a given size is largely a function of controlling the heating or potential heating of the wire. You want to avoid having the wire heat up to the point that it has a detrimental effect on its environment, its insulation, or itself. The intended use of the wire has a lot to do with this. In the case of a traditional incandescent light bulb, we are quite happy to pump a lot of amps through a very small uninsulated wire, because the heating is acceptable in this context.

For commercial wiring, heating that causes the insulation to deteriorate over time is unacceptable, as is heating that might trigger a fire. So the amperage ratings are very conservative, for good reason. From a commercial wiring perspective, you want to be able to draw the full rated current continuously forever without any significant heating.

Now, our stepper motors actually have wires inside that are even smaller than the motor leads. However, they are assembled into windings with heat tolerant insulation (varnish), and the assembly itself acts as a heat sink within reason. This is why the motors have temperature ratings; if allowed to go to high, a insulation or a wire will melt somewhere, short, and set off a cascading failure.

But when you look at how a stepper motor is driven, it doesn't draw the full amperage continuously. It's varying all the time. So it doesn't heat the wire as much, and you can use smaller gauges than you might normally. This shows up as those threadlike motor leads.

This brings us to the last point, which is that the wires on a CNC machine undergo a fair amount of physical stress as they are dragged back and forth, and they can be fairly long. This calls for upsizing a bit to compensate for wear and resistance. 13ga for 6.3a seems a bit more than necessary, but it's consistent with Mike's engineering principles; he likes to run his motors and electronics as cool as possible, and use large wires in order to build systems that will not have failures. There is a lot of wisdom in that.

I think you would be fine with 16 or 18ga wire. Geckodrive recommends 14 or 16 gauge wire from the power supply to the drivers, and 22ga wire afterwards.

So, there ya go, 13ga at one end of the spectrum, and 22ga at the other. Pick your poison. I use 18ga.

Thanks Brad and also Mike Richards, you both are my electronic teachers. The way you both explain these mathers are awesome and make perfectly sense to me. I'm learning and learning.

Polder

My first thought was "that can't be right. Mike is just going gold standard or something". So I google'd the question and came up with a chart that matched Mikes' numbers exactly. OK, this seems to be a known value. Better have someone explain this to me. Thanks Brad, you done good.

Its like selecting pipe size when you lay your plumbing... when you need a certain flow rate, (current), you don't normally choose the pipe size that is just right or smaller than it is required. a slight oversize give some guarantee on the reliability & longevity.

wire gauge / voltage drop
 

I'm about to place my cable order, and having difficulty making up my mind on the 4-conductor motor cables.

With my size of table and control box location, I'm looking at a 50-foot run for the the Y and Z motors.

I looked up voltage drop for DC power wiring in the technical standards published by the American Boat and Yacht Council (ABYC). They have tables for 12V, 24V and 32VDC (the most common sizes found on recreational boats).

Taking the 32VDC table, a 100 foot cable run (to the motor, and back) carrying 5 amps, for a 10% allowed voltage drop, is specified at 16 gauge. For a 3% voltage drop, the requirement is 12 gauge.

So playing a bit loose with the numbers, I'm running 35VDC to the motors, so with 16 gauge I'm already down to 31.5VDC at the motor. The tables don't specify anything smaller than 18 gauge. But I'm wondering... with 20 gauge, what's actually showing up at the farthest motors?

Michel, have you considered moving the control box closer to, or underneath the table? It might be more straightforward to have a long cable from the computer than to have long cables to the motors, spindle, sensors, and switches.

If you do go with the 50' run, I'd upsize one gauge (lower number).

Ah, there's the rub. I've already decided to mount the computer (mini-ITX) in the control box. So I'd now have to decide where to locate the keyboard, mouse, and monitor.

Hmm, there may be merit in this approach, using a KVM extender.

So, in looking at McMaster Carr's site, I found this...

9700T41
Cable-Tray Rated Continuous-Flex Multi Cable Shielded, 18/4 AWG, 600 VAC
Quantity Per Ft.
1-99 Ft. $2.27
100 or more 1.82

This seems to be comparable or lower than some of the other prices being listed. Is this the right wire for the motors? Is there a cheaper source for it? I just got some stuff from McMaster (2 days after I ordered it) and am really happy with their shipping and products at this point. So if its a reasonable price, I'm perfectly happy with going with them. Thoughts?

Is there a particular reason not to include the 2 core E-stop wiring with the 7-core signal wires? Is it just industry standard that it is a separate wire, dedicated to the task? It seems more economical to go with a 9/10 core wire than to have a 7 plus a 2. Am I missing something really obvious? It seems like, for the most part, they go to roughly the same spots if you position your boxes opposite the sensors for the e-stops.

Am I missing something really obvious here?

One of the e-stop circuits has a mains voltage (to open the contactor). You don't normally mix mains voltage and low signal voltage within the same cable over a long distance.

That would be the obvious part that I was missing...

Thanks. :)

Eric are you using the 126 BOB on your build?

Yes, I will be. Downloaded the manual a couple of days ago, am still working my way through it. Going to order that and 4 geckos 203Vs in the next day or two.

Hey mates,

I got in contact today with the distrubutor for Lapp kabels Croatia, and they sent me over their catalouge to check which cables i need to order.. i checked for the ölflex classic 115c in the catalouge but found only ölflex classic 115cy which by reading the product description doesnt seem to fit our needs... Now i dont know if they changed something in their brandings or the product does fit our needs, but they dont tell it to us in their data sheet because they got something "more" specialized for this purpose..

Now, im gonna copy the link to the catalouge (43 mb) its in english, so if anybody could check this i would really aprecciate it. Also, why doesnt the cables have 8 cores , but 3,4,5,7 and then 12?? I must admit that my knowledge of electicity comes down to lights on/lights off but on the other hand a man told me sometime ago that there are no dumb questions, just dumb answers :-)

I also talked with a forum member who mentioned that LiYCY cables should be my choice, i checked them out (gonna copy that link too) and by reading the description they seemed to my unknowing eye more appropriate... This data sheet is in croatian :-( but maybe you guys can figure it out by the technichal terms, they should be readable to a broader audience..

Ok here are the links:
Lapp kabel catalouge
http://www.tim-kabel.hr/images/stori...l/APPENDIX.pdf

LIYCY data sheet
http://www.tim-kabel.hr/images/stori...1101_LiYCY.pdf

Thanks in advance for the incoming wisdom ;-)

Greeting from finally a little rain but mostly hot as hell Croatia

You can use 4 cores wire. No need for 8. I had that available that is why I used it.
I got that LIYCY cable on 2 machines working 2 years now.

Just reading and learning about half coil/full coil setup... Why not 8 wires full coil? Sorry if offtopic...

Because if you looked at your drives Branko you have only 4 outputs to motors?
Bipolar drives have only that much, A and B phase. So you can lay 4 core wire to the motors and make the combination of wires at your wish there .

Still learning.. :-)

What does anyone think of the Lapp Olflex 190cy products? Are these acceptable? The current pricing seems to be less than the Olflex FD-855 and FD-855p.