I will probably change my order to a 12 core cable then. Thanks a lot guys. I'm a quick learner (when people explain to me realllllyy slowwww :)).

Keep an eye on the outside diameter of the cable - if it gets too thick it will not like to flex inside the cable carrier.

After a lot of consideration, I have decided to reduce wire gauge (go thinner) for our stepper motor wires. Originally we used 1.0mm² (18gauge), which was a match to the Gecko's capability of 7 Amp and when we toyed with going to bigger motors in the longer term, which included the possibility of paralleling the coils in some motors.

Since then we have moved away from big, high-current configurations and I cannot realistically see our personal situation going over 3 Amps. Mariss has also written some interesting comments on why stepper motor cables can be really thin. (See post of 08 September 2007 in this thread)

So, we will be ordering 172 meters [564 ft] of 4 core 0.5mm² [21 gauge] screened cable tomorrow. (R13.92/meter [$0.57/ft]) Ölflex Classic 115CY 4 G 0.5

I was wondering why I was taking so long to make up my mind on the final order of my cables, this must be it :).

Do you think I will be safe to use the same for my 4.5amp (PK299's) motors or is that pushing the envelope a bit much?

Is that price excluding VAT?

ps: could you give us a breakdown of the cable lengths you are using for each run, all the other lengths on this thread are for "small" 8'x4' machines, I just want to check them against my estimates to make sure I am not buying too much and wasting cash. It might be of benefit to the other SA guys building to our bigger size.

Alan what lengths cable chains did you get from RS? I need to order mine also.

I think it is technically okay for the 4.5Amp motors. See the post by Mariss referenced above. We shouldn't see warm cables, even when a couple of them are bundled together. My biggest concern on reducing the size is their strength where they enter connecters and terminals, but I think that I have learnt to be careful in that department.

Here is the "calculator" for the lengths. Some of the allowances on the y-car seem far too generous, but we have verified them by actual measurement . . . .

Gerald

Thanks for the calculator, it mostly confirms my estimates.

I see you have changed to a 5 core cable for the "power" to the junction box on the y-car, why the extra core (2 for fan, 2 for thermistor)?

ps: the pdf file in the above zip only shows half the junctionbuttonboxes drawing, B end of gantry is cut off. fixed

Gerald, another question

Cell E14 gives the length of the 220V E-stop (2 core) cable from the 2PB to the Y-car, what about the length of cable from the control box to the 2PB box, how does the signal get back to the box. This may tie up with my query above but surely you need two wires to carry the signal back to the contactor?

It is also the junction for the mains E-Stop.

Puts the little fan on the wrong side of the e-stop contactor, but still on the right side of the isolator . .

:o OK got it worked out, not too bright this morning.

A 1 amp mains supply to the y-car may have more uses . . . .

Inexpensive wire source
 

I just got an email from Vladimir of Skycraft Parts and Surplus http://www.skycraftsurplus.com

He has Belden 7402A wire available for $0.162/foot. Mouser sells it for $160 for a 250' spool.

Unfortunately, I already bought my wire, and paid quite a bit more for probably inferior wire.

But that is un-shielded wire?

7402AS is shielded

http://www.belden.com/pdfs/03Belden_...s/18.31_40.pdf

screened cables
 

After reading this post i had a look at my shopbot prt97 stepper motors
cables. None has any screening on them.
not sure if the later shopbots are screened.
i was hoping to hook my Mach3 control board to my existing cables
but if there is the possibility of problems i will have to order new cables.
or run with existing cables for testing then import correct cables.
any feedback would be a appreciated.
paul

Paul,
As far as noise goes, I would aways prefer a shielded cable over a non shielded. The control signals are the ones that really need attention, anything that is low voltage control signals (estop etc). I would suggest making sure those are screened at the minimum. The motor cables wont care about noise themselves but a shielded cable there will help them not to radiate noise out to other things. So you could do it in steps if you wanted.

Paul,

From my little experience, I would agree with Heath. Shielded is better.

Use your existing motor cables for a start. Your e-stop is the one that most needs a shielded/screened cable. Or keep the e-stop cable far away from the motor cables.

If all your cables are screened/shielded, then you can stop worrying about keeping a distance apart.

screened cables
 

Thanks for your replies, very helpful. will go with what i have and replace with
screened cables once i have everything going
paul

Gerald,
In the essence of keeping cost down but no sacrifice to risking trouble, how important is it to have screen cable for a router source.
Can a regular 14/2 for a router attract some possible trouble ?
Not a big deal, +/- 120 us $ for a 14/4 new shielded cable ( I say 14/4 cause 14/2 or 14/3 difficult to find ! ), but if not necessary, then....why ! !
Thanks, Robert

Time for me to air some dirty laundry:

My motor wires are screened. My estop circuit wire is screened.

My proxy sensor circuits and z-zero circuit are not screened, although they are run as twisted pairs; the whole set is in one cat-5e ethernet cable. My router power was not screened, and my spindle power is not screened.

I'm not 100% comfortable not screening the spindle power lines, but I had the wire lying around and I wanted to get the spindle up and running. If anything goes unreliable, it's the first thing I'll replace during debugging.

In my thinking about this, the motor cables are a potential strong noise transmitter; they are high power lines at high and varying frequencies.

The router power was relatively insignificant; it's high power, but at a consistent frequency, and there's plenty of other unshielded lines of that ilk all over my shop.

The spindle power is a likely the strongest transmitter in the shop, but thus far no issues.

The proxy switches are not a transmitter, but might be a receiver of noise. However, the consequences of a noise problem are minor from a safety perspective, and they are very basic on/off signals.

The E-stop is in it's own shielded wire, because, well, it's the E-stop.

So, I think you're okay not screening the power to a router, especially if it's just on/off. If you are using a speed control external to the router, then you might be more careful. Of course, if anything goes weird, the first thing to do is switch to a shielded cable.

The routers have brushes and the brushes wear out. Have seen too many reports of folk that cure their noise problems by running the router cable straight up to the ceiling and far away from the other cables. The router cable is high on my list for getting a shielded cable.

Good point. Dirty commutators and brushes sparking would be a substantial noise source. Missed that one.

could this cable work?
 

I need some opinions on this cable that I came across.This is the numbers and wording on the cable. "THE SIEMOM COMPANY SYSTEM 7 E116394 4 PAIR 22AWG SOLID CMP 75C (UL) C (UL) S/STP 2005 1102. There is a description of the wires. green/gray pair,pink-gray pair, brown/gray pair,gray/lite gray pair with a foil wrap around each pair. There is a small(.019")bare wire in the cable. I have the shield wire pulled back over the blue jacket.

http://i671.photobucket.com/albums/v...dsParts135.jpg

http://i671.photobucket.com/albums/v...dsParts137.jpg

The second most important thing about the wire in my opinion is that it is stranded not solid. The more strands in the wire the more times it can bend without braking. The armored shielding on the wires is not that important, if the wires are not rubbing on anything (e.g. run in cable chains). That is my opinion.
Also 22awg is very thin I believe that most are using 14 to 18 gauge for the motors. Sensor and input wires can be quite small.

My MM uses 22 ga wire approximately 30' long. After an hour of heavy use, the jackets on the wires are about 10-15° f above ambient.

I have a 57v power supply, and my steppers get much warmer than that... call it 130° f.

Jimmy,
The solid wire will not be very flexible and could break over repeated bending. Foil shield is good but foil and braid is better. I would probably opt for stranded wire.

Hi you all,
If Ill be using a 115V circuit for the e-stop, will a 20 AWG gage be all right or should I move to a 14 AWG?
Thanks....
Hector

Hector, the gauge (size of the conductors) affects the current handling capacity of a wire. The voltage that can be safely handled is a function of the insulation wrapping the wire. Most modern wire insulation is well up to handling any voltage you are likely to use, however, if the voltage is potentially dangerous, you'll also want to be sure that there is a low likelihood of physical damage to the insulation that could expose the voltage. So 20 AWG is just fine for your e-stop, as long as your e-stop circuit doesn't involve more than about 5 amps worth of current, and you a comfortable that the insulation won't get beaten up. See http://wiki.xtronics.com/index.php/Wire-Gauge_Ampacity

Looking to rip out my cheap "security" cable as its not going to be the best long term cable for a cnc router. Has worked without failing but I don't want it to be running if it does fail. Really interested in this continuous flex control cable a few of you including Gerald have mentioned and or used on your mechmates. Wondered where any of you in the US have purchased this cable (either Lapp OLFlex classic or Igus Chainflex) and if you recall off hand how much you were paying per foot. I contacted Lapp USA and the rep tried to talk me into a more expensive more over the top robotic cable :rolleyes: that was around $7 a foot. I'm sure its good but I don't plan on ever running these cables nearly as much as they are rated for nor do I need the ratings/specs they carry.

Thanks in advance for any info.

Brian,

I and others purchased our cable from this Ebay Store. I purchased 200 feet of 7 core, 20 gauge, stranded copper, shielded cable from him. I don't see it in his Ebay store at the moment, but send him a "question" using his Ebay store to check price and availability.

He was very helpful to me and has good service. He responds to questions, so be sure to ask. For instance, his store didn't say whether the wire was copper and stranded. I ask him, he repsonded, and it was. The delivered product was exactly what he told me it would be.

Thanks for the info I will contact that seller. Was hoping for a true distributor but ebay always works. From what I can tell Igus has more affordable continuous flex cable, but I'm still interested in Lapp's. Can I ask why 7 core? Aren't your motors 8 wire/4wire in parallel?

Brian,

You are correct, my mistake, the wire for the motors was 4 core.

The 7 core is for the E-stops, etc.

As I recall, (my MechMate is not my current location), I ended up using two 4 core cables instead of one 7 core cable for my E-stops, etc. I appologize for not being more careful in my reply.

No need to apologize ;) appreciate any info you provide. Got Igus's catalogs today and will request samples tomorrow, Lapp has still yet to send me a catalog after requesting twice. Igus was prompt and so professional. Making me lean more and more towards Igus's chainflex. Always loved their cable carriers.

cnc supplier items
 

Found this information on ebay might be of interest to others
woodguy
http://cgi.ebay.com/CNC-Stepper-Moto...item3ca0a476e6

That's pretty cheap but I think you get what you pay for. No brand name on it but is his description true? That stepper motors def. do not need to run with shielded cable? I'm sure it would take an awful lot to get a response from a stray signal to foul them up but I would rather not take my chances and just keep it shielded. Also 7 strands per conductor? I think some of the other flexible cable mentioned in this thread is around 25-30 strands per conductor? Wonder how flexible that cable really is. :o

Woodguy,
That wire is an unshielded wire. Its better to use shielded wire throughout the system to control noise. You also want the shielding on the stepper cables to keep the noise on them IN. :)

Hi all,

To those who would be interested or are wondering which wireing to go if you should / want to use IGUS Chainflex screen cable, here’s a few part # that I ordered for the beast !

- Motors, No: CF6-07-04 ( 4 conductors x 07mm (18awg))
- Data, No : CF6-05-07 ( 7 conductors x 05mm (20awg))
- Data, No : CF6-05-09 (9 conductors x 05mm (20awg))
-Roter/spindle : CF31-25-04 ( 4 conductors x 2.0mm (14awg))

Decided to go with IGUS for some few basic reasons:
First, in my case (in Canada) LAPP has no corporate warehouse, no distributor for the wire needed which means it had to be brought in from a office agent who in turns get’s it from USA main warehouse, which again meat I had to pay an astronomical price ( +/- 20-25%...freight, customs, duty…etc, more than what IGUS cost me at my door steps) but …the focal point aside prices, the LAPP agent knew basically zippo about some very basic tech info I was hoping to get and I had to run after him to get 1st a quote…. and that goes with he never returned my calls about turnaround time on an order nor a bitch attitude over the phone !?

IGUS, well, it was a fun experience.
1st, they have a local corporate rep that came the very next day I 1st called with some catalogs in hand !!
Call on the guy afterwards and get knowledgeable tech info, prices and anything else you can think of, related to what they offer and get answered with a friendly attitude on the fly anytime of the day. Just can’t say that nor could not find anyone for BELDEN and LAPP…well as said, rather eat sand than call on those arrogant bitches again !

So, as I can understand in some other countries, IGUS can be more money, but for me, cost less and get service & courteous answers…. Even if sometimes it can cost more, it is worth a little more $$....best of all, here in Canada it cost 2 to 3 time less than LAPP !!!

My Mechmate obsession has led me to scourer the internet, local stores, papers, dumpsters, and drainage ditches for shielded, braided, four conductor wire that would not break the bank but would ensure a successful Mechmate. I have even considered starting a new company to manufacture this product at a reasonable price, given the totally absurd prices I have received from several vendors, when I found this in the Mouser catalog http://www.mouser.com/ProductDetail/...CWtLf%2fdKc%3d . It does not have a braid but it is shielded and is specifically designed for our application. It has been tested to 14,000,000 cycles which means it would probably last around 39 years in my little shop (1000 cycles per day). It’s 22 awg, a bit thin, but as Gerald has argued should be perfectly fine, it has a jacket diameter of .231 inches and bend radius of 8x its diameter for both static and dynamic use. Here’s a link to the Alpha Wire web page which better describes the product http://www.alphawire.com/Products/Ca...x/86304CY.aspx . Press the properties tab for specifics. At around .70 per foot that’s a bargain in the US for a viable solution. I know that many of you insist on the braid for fear of the foil alternative, wearing during use, but with a fourteen million cycle rating and at dramatically lower cost I’m inclined to try it. I’d appreciate your opinions before I lay down the $350 for a 500 foot roll.