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-   -   Screened flexible cables (wires) - specifications & sources (suppliers) (

fabrica Mon 08 January 2007 04:46

Screened flexible cables (wires) - specifications & sources (suppliers)
This thread has been trimmed. The original is in the archive here:


How many wires go from the Gecko drive board to the steppers? Do all wires have to be screened including the power cables?

Gerald_D Mon 08 January 2007 07:12

We must be careful of the words here because we don't want any confusion....

There is a single cable from each gecko to each motor. That cable contains 4 wires (4 cores). Also, around the cores/wires is a single metal screen/shield. The screen/shield is not connected to the motor, but at the gecko end the screen/shield is connected to ground/earth point (the plate "under" the gecko). These cables can be about 11 meters [35 ft] long each and they need to be fairly flexible. We used 1.0mm2 Ölflex from Lapp

I am not sure what you mean by "power" cables?

fabrica Tue 09 January 2007 02:47

Thanks for your info Gerald, What price did you pay for a meter of the Lapp cable that you are using? the local guys are quoting around US $ 5.00 per meter for Pirelli brand.

One more thing Gerald, Did you find any specific part number for the Olflex cable that you are using?

Gerald_D Tue 09 January 2007 05:42

The full description for the stepper motor cable is "ÖLFLEX CLASSIC 115C 4 G 1.0mm sq" which cost me $1.65 per meter (50cents per foot)

fabrica Tue 09 January 2007 12:29

Thnaks Gerald for you effort. This stuff is not avilable localy. I will will have to import this from Singapore where they have stockists for LAPP.

Gerald_D Tue 09 January 2007 13:04

If you are doing a special import, then you need a complete list of all the cable types running to the gantries and cars - all these cables need to flex and all should be screened. (Your laser may also have special cable requirements)

This is what I have on the MechMate now:

4 cables, 4 core, 1.0mm2 for the 4 steppers
1 cable, 4 core, 1.5mm2 for the spindle main motor. (9 amp)
1 cable 4 core, 0.5mm2 for the spindle fan and thermistor
1 cable 7 core, 0.5mm2 for input/output signals from the breakout card (not all cores are used yet)
1 cable 4 core, 0.5mm2 for 220V power/control. (2 cores used for E-stop)

(I recall that I ordered 11 meters to the z-axis and a bit shorter to the back x-motor - my control box is high on a wall behind the walking area)

There is also a single green 6.0mm2 cable for ground/earth (not shielded). This you must have locally.

The price of copper went up internationally by about 50% last year - of course that is the excuse why cable prices have risen sometimes by 100%!

fabrica Thu 11 January 2007 11:57

Given below are the prices which I receved from my Singapore supplier(ex-works singapore) for LAPP cables. Hopefully this info would be of some benifit to the other guys on this forum.

1. 4 Core 1.00 mm2 [18 AWG] for steppers (Part No 1136204) SGD 2.70/mtr (US$0.53/ft)
2. 4 Core 1.5 mm2 [16 AWG] for spindle (Part No 1136304) SGD 3.60/mtr (US$0.71/ft)
3. 4 core 0.5 mm2 [21 AWG] for Fan/Thermister SGD (Part No 1136004) 1.95/mtr (US$0.39/ft)
4. 7 core 0.5 mm2 [21 AWG] for BOB control card (Part No 1126107) SGD 3.60/mtr (US$0.71/ft)

The above given prices are quoted in Singapore Dollars. (I added the US$'s - Gerald)

Gerald_D Thu 11 January 2007 12:43

Here is some info on those cables:

reza forushani Sun 11 February 2007 22:28

How many meters/feet of each cable do we need to order?

Gerald_D Sun 11 February 2007 22:53

See Doug Ford's summary later in this thread

reza forushani Mon 12 February 2007 08:39

. . . . . I am going to start with a router and see what happens. So should I use 2.0mm2 [14 AWG] for that since you mentioned thicker for router?

Gerald_D Mon 12 February 2007 09:17

When you use a router out on a construction site with a long cable, what gauge wire would you be using? I presume you are talking 110V and quite a lot of amps? The gauge (mm2) of the router cable for the MechMate will be the same as that. (Our cables in this country, or Europe, would be thinner because we are 220V)

Modified for a 115V router application: . . . . . . . . .

4 cables, 4 core, 1.0mm 2[18 AWG] for the 4 steppers
1 cable, 4>3 core, 1.5>(2.0)mm2 [14 AWG] for the spindle main>router motor. (15 amp?) 2-core if router has only a 2-core cord.
1 cable 4 core, 0.5mm2 [21 AWG] for the spindle fan and thermistor >
1 cable 7 core, 0.5mm2 [21 AWG] for input/output signals from the breakout card (not all cores are used yet)
1 cable 4 core, 0.5mm2 [21 AWG] for 220V power/control. (2 cores used for E-stop) (only 2 cores are needed, but you might not be able to get it)

Gerald_D Mon 12 February 2007 11:05

Apparently 14gauge or 2.0mm2 is right for a 15 Amp single phase router in 110V countries.

In 220V countries you can use 1.0mm2 for the big routers because they will draw around 8 Amps at the higher voltage.

Gerald_D Wed 18 April 2007 11:24

I have just counted the strands in some Lapp Ölflex Classic that are here at home:
1.5mm2 30 strands (16AWG)
0.5mm2 16 strands (21AWG)
Their spec, from the links above, says bend radius of 20x where there is movement and 6x for static. Maybe I went a bit overboard with my cables for this application? Cables are seldom discussed on all the CNC forums.

Gerald_D Thu 26 April 2007 11:56

I've just remembered how I actually found the economical cables.....phoned around an asked for the "simplest/cheapest braided screen cable that you have - not aluminium or Mylar foil - proper braid"

Håvard Sun 13 May 2007 03:14


I feel a bit stupid to have jumped right in here. I did not realize that the cables get thinner when the AWG increases... Who came up with those units anyway? I'd like to tell them a little something.

Gerald_D Mon 14 May 2007 10:48

Gerald D Sat 08 September 2007 08:27

My suggestion for the motors has always been 18 gage, mainly because it is a substantial, strong wire. You could go thinner. Quoting Mariss Freimanis on 29 Aug. '07:

"Most will agree 22-gage wire is pretty small (0.64mm or 0.025"
diameter). Let's see how it would work out wiring to a 7A per phase
motor 10' (3m) away.

22-gage wire has 0.16 Ohms resistance for a 10' length. Two wires are
needed per coil so that's 0.32 Ohms. The voltage drop will be 2.2V due
to wire resistance at 7A. If your power supply voltage was 65VDC then
it just became a 63VDC supply as far as the motor is concerned. Will
your motor know the difference? Not at all; it draws 7A at low speed
where supply voltage doesn't matter.

At high speed your motor phase current drops to 3A. The cable drop
becomes 1V, the supply becomes 64VDC instead of 65VDC. Does the motor
care? Not at all again.

Will the cable melt? Cable dissipation is 7^2 times 0.32 or 15 Watts.
That works out to about 1/8W per inch. It will be warm but not hot. At
high speed it's 3W and 0.024W / inch. Not even warm."

Doug_Ford Fri 05 October 2007 20:24

There were many posts on suppliers prior to this one below - those posts are in the archive:


I think I've found a reasonable deal on cable for us North American builders and I'd like to get your opinion on its quality. It has a braided shield and a 10X bend radius.

The salesman at Tannehill is named Dennis and was very helpful. I gave him the part numbers for the Olflex 115CY cable you said was good. He said they didn't have it but that Helukabel makes exact duplicates of the same stuff (type F-CY-JZ , flexible, Cu-screened, grey) and he'd get those prices for me. He called back later with the info below.

Here is the link to the cable on Helukabel's website.

These are his prices:

1.0mm squared (18 AWG) 4 core - $1.44/foot
2.0mm sqd (14 AWG) 3 core - $2.42/foot
0.5mm sqd (21 AWG) 7 core - $1.55/foot
0.5mm sqd (21 AWG) 2 core - $.93/foot

For each type of cable, there is a $25 cutoff charge.

He said the prices he quoted me could be obtained by anyone who wanted it. If Gerald says this is good stuff and anyone else is interested, Dennis's contact info is:

Dennis Holtgrave
Lapp Tannehill, Inc.
8675 Eagle Creek Parkway
Savage, MN 55378
952-881-6700 ext 3614
952-881-0743 fax

PS. I left a civil voicemail for the sales manager at my local Carlton-Bates but he never called back.

Doug_Ford Fri 05 October 2007 20:27

Oh yeah. Thanks Mark. And GaryC, I'm looking for braided shield so I don't have weird problems popping up later when the foil wears out. Thanks for the referral anyway.

Gerald D Fri 05 October 2007 21:02

Those Helukabels look just right technically, but it is still expensive compared to other parts of the world. Your government may have a high import tax on foreign cable from Germany . . . .

Doug_Ford Sat 06 October 2007 09:35

Thanks Gerald. Yeah, I noticed they were expensive but the price seemed to be a bit lower than what other guys had been posting over the past few months. Oh well, we all have our challenges getting parts depending on where we live in the world. I guess the ideal fulltime job to have, if you are building a Mechmate, is an international airline pilot.:)

Doug_Ford Sat 10 November 2007 20:24

If anyone is planning to order cables soon, please wait. Within the next couple of weeks, I hope to finish routing the cables on my table and I'll try to give y'all a more accurate estimate of the lengths required. This stuff is pretty expensive so you don't want to waste any if you can help it.

Tonight, I almost ripped out the Y axis e-chain so I could reverse it. I thought I might be able to save 6-7 feet of the 2 core cable used in the e-stop circuit. Then I realized that if I reversed the e-chain, I would use more 4 core cable used to run the motors. Anyway, I think everyone will need to order more than 35 feet of the 2 core e-stop cable. Mine ended up short and if I don't splice on some extra, I'll have to mount the control box on my table like Hugo.

smreish Sat 10 November 2007 21:36

Good note Doug.
A great source for "cut as much as you need" is from Skycraft Surplus in Orlando, Florida. They have a website and do mail order. They stock many 4/6/7/9 core chainflex/olflex and others for cable chain use. It all starts in the .43/ft range and goes up.

Doug_Ford Mon 12 November 2007 18:06

Today, I added the cables to my machine which is built to cut 49 X 97 inch sheets of plywood. In order to calculate how long to cut the cables, I took alot of measurements. I figured new builders could use this information when placing their orders so that they don't order too much or too little.

My recommendation is that a new builder wait until he has the table, gantry and car built and the e-chain installed so he can take his own measurements. He should also thoroughly understand the E-stop, pause and resume circuits so that he can mentally walk through the process of routing the cable. It isn't complicated but it also isn't as simple as it may seem. I routed my E-stop circuit incorrectly and I wasted some wire that I now have to reorder.

**IMPORTANT**: The cable lengths I'm showing below are from the point where THE CABLES ENTER THE MACHINE. That is the point where the e-chain is anchored to the table. If you order your cables without adding the distance to the floor, across the floor to the wall and up the wall to your control box, YOUR CABLES WILL BE TOO SHORT. You must decide how far the control box will be from your MM and how high the box will be on the wall and add that to your order. Also, ensure that you include in your measurement the distance inside the box to the component to which you will connect the cable (relay, Gecko, Terminal, etc.).

- Stepper motor cables. Each motor is connected directly to its Gecko drive in the control box using a 4 core cable.

Z-axis motor - 18 feet 6 inches + distance to control box
Y-axis motor - 18 feet 8 inches + distance to control box
X-axis motor (front) - 16 feet 6 inches + distance to control box
X-axis motor (back) - 7 feet 6 inches + distance to control box

- Router motor cable. The router is connected to the relay in the control box. You only need one of these two core cables. Its length is 18 feet 6 inches + distance to control box

- E-stop circuits. There are two E-stop switches under each E-stop operator (or button). One switch is connected to a circuit that shuts off the contactor. You need a separate 2 core cable for this circuit. The other switch is connected to a circuit that uses the PMDX breakout board to perform the stop. The wires for that circuit are part of the seven core cable. The other wires in this cable are for the pause and resume circuits. Both the 2 core cable and the 7 core cables are the same length overall and may be routed along side each other.

Both the 2 core and 7 core cables will be divided into three pieces:
  • The first cable will be 7 feet 6 inches long + the distance to your control box. That cable will run from the control box through the X-Axis echain to the E-stop/Pause/Resume box mounted on the gantry on the backside of the MM.
  • The second cable will be 9 feet long and will run from the E-stop/Pause/Resume box mounted on the gantry on the backside of the MM through one of the gantry tubes to the E-stop/Pause/Resume box mounted on the gantry on the front side of the MM.
  • The third cable will be 11 feet long and will run from the E-stop/Pause/Resume box mounted on the gantry on the backside of the MM through the Y-axis echain to the E-stop/Pause/Resume box mounted on the car.
Be sure you connect the E-stop switches in series.

Please make sure you give yourself some additional wire so that you have working room to strip and make connections to the switch terminals.

If you are building a machine that cuts larger sheets of plywood, you will need to change these lengths.

gmessler Mon 12 November 2007 19:34

Thanks for the info Doug. :)

Gerald D Mon 12 November 2007 20:34

That's very useful Doug! Thanks!

Doug_Ford Mon 12 November 2007 21:23


Please check my work. I could be wrong. Heck, I can't even wire up a contactor.:o

Gerald D Mon 12 November 2007 22:51

1 Attachment(s)
This is how a single cable is internally looped to get a series connection between switches:

That second pair of cables that Doug mentions for the e-stops . . . .
- from the button box on the "far" side of the gantry, furthest from "home" position
- to the button box on the "near" side of the gantry
. . . . . is static cable - it can be be stiff foil-screened cable - it is not required to flex.

Marc Shlaes Tue 13 November 2007 18:19

Doug, relax!

You have done a wonderful job on your machine in a very short time. If you were perfect, I don't think you would be working for a living.


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