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fabrica
Mon 08 January 2007, 03:46
Gerald,

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, 06:12
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, 01:47
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, 04:42
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, 11:29
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, 12:04
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 shielded. (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, 10:57
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, 11:43
Here is some info on those cables:

http://www.lappusa.com/Spec_Template.asp?nGroupID=10114

reza forushani
Sun 11 February 2007, 21:28
How many meters/feet of each cable do we need to order?

Gerald_D
Sun 11 February 2007, 21:53
Reza, this depends on the size of table that you are going to build, but mostly depends on how far you are going to locate the control panel from the table. It also depends on whether you use a router or spindle (routers need less, but thicker, wires than a spindle). There is no harm in laying extra cables in case you want to change from router to spindle.

In my particular case (9'x 6' table, spindle, control box 8' from table) the cables were an average of 35' each. (The x-motors need shorter cables than the y&z-motors).

reza forushani
Sun 11 February 2007, 23:29
so is that 35 meters of the 3 types of wire or 35 meter of wire for each axis?

Gerald_D
Sun 11 February 2007, 23:46
Oops, lots of confusion - I see now from your profile that you are in Atlanta but work in the metric system. I gave you feet ('), not meters.

The length of cable from the gantry/cars/motors to the control box is about 11m [35' (feet)]. Therefore, each motor needs a cable about that long. Plus you need cables for other devices as well.

reza forushani
Mon 12 February 2007, 07:39
Working late last night got me thinking meters. I was confused. Yes I work with feet, was just tired and not thinking straight. 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? How much of the 7 core? and the last one for power/e-stop does that run to the table? What location?

Gerald_D
Mon 12 February 2007, 08:17
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)

35' of the 7-core

also 35' of the power/e-stop cable - it goes to the red E-Stop button/s on the moving gantry.

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, 10:05
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.

reza forushani
Tue 13 February 2007, 16:41
I got these prices today. Aren't they high?

Omni Cable A1211804 $1.67/ft
Omni Cable A1211404 $2.54/ft
Omni Cable A1211807 $2.57/ft

These are supposedly equivalent to lapp cables. Plus freight from NC. What is everybody else doing for cables? Any internet source with better prices? This comes out to about $500.00 for just cables.

Hugo Carradini
Sun 04 March 2007, 12:11
Gerald. ¿Would it be OK to you use Alpha Wire Mouser part number 602-2424C-500 and 603-2433C-500 for motors and router?
Thanks

christipher saint denis
Mon 02 April 2007, 11:23
Reza
If you don't mind me asking, what brand of cable did you end up purchasing and what supplier? I contacted a Michigan distributor of the Lapp Olflex and they are charging for $3.50 to $4.75 per foot. I have not contact Lapp directly I have just called a few local distributors.

Anyone found a reasonably priced US supplier? I will keep up my search.

Thanks

David Smith
Tue 17 April 2007, 16:55
would this work?
http://www.ramcorpwire.com/products.php?cat=8

they have 2, 4, 6 and more conductor shielded unshielded
12, 14, 16, 18ga gray pvc cable if so seems to be a good price

Gerald_D
Wed 18 April 2007, 02:29
I did a quick check of that site and could not find specs of bending radius, strand diameter or even comments about the suitability for continuous movement? Our application is not high speed robotics, but we do want some flexibilty in the cable. You might need to call Ramcorp to find out a bit more?

David Smith
Wed 18 April 2007, 09:51
So I e-mailed ramcorp and this was there reply

"Our cables are typically 7 strands for the 18 Gage and 19 strands for the 14 & 12.
These are somewhat flexible although, they are really not intended for a continuos flex.
Typically the bend radius is about 20 times the diameter."

so i will look for somthing better I realy don't want to scrimp on the cables

Gerald_D
Wed 18 April 2007, 10:24
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.

David Smith
Thu 19 April 2007, 16:47
well I found a local company that can order me omni cable price ranges between $1.78 and $2.35 a foot for 12,14 and 16ga.
I'd rather go heavy and not worry about the amps. One of the porter cable routers at work is rated 11 amps. anyway I want to
make sure I order right. I need?

4 cables, 4 core, 14ga for the 4 steppers (again all of these are most likely way overkill)
1 cable 4 Core 12ga for router or upgrade to spindle
1 cable 7 core, 16ga for input/output signals from the breakout card (to where?)
1 cable 4 Core 14ga for E-stop

anything I'm missing?

Thanks
Dave

Gerald_D
Thu 19 April 2007, 23:11
Welcome David!

Before I look at your ga sizes,....
- are the cables screened or shielded?
- how flexible are they?

My first impression is that your cables are too thick, causing flexibility problems?.......

David Smith
Fri 20 April 2007, 16:20
Hey Gerald,
They would be shielded but I could not find the specs online so I called the company and was not impressed with the help I received.
The good news is that I found another website that has almost too much selection and info. http://www.hitechcontrols.com/index.htm
I called and they seemed to be very helpful and said they would research the specifications I gave them and get back to me.
Anyway I will post the part#?s and pricing when I get them.

Dave

Gerald_D
Mon 23 April 2007, 23:12
David, those are extremely high-spec and expensive cables. Fabrica and I got the Ölflex cables at under $0.75 a foot. Our cable has a 20x bending radius for flex, yours is twice as good. I don't see any downside on your selection, other than the price.

Here (http://www.lappusa.com/PDF/Pg52-Olflex115CY.pdf) is the USA specsheet on the Ölflex - what happens if you call the number at bottom right on that sheet?

18 AWG 1.00 mm2 is fine for the stepper motors, you don't need any thicker.

Gerald_D
Mon 23 April 2007, 23:29
Found useful Alpha info here:

www.alphawire.com (http://www.alphawire.com/)

I have a funny feeling the Ölflex 115CY has been discontinued and no longer meets codes in some countries - that's why it finds its way to South Africa and Sri Lanka? Looking at its contruction, it only has a very thin clear layer between the shield and the inner cores, making it small overall (and maybe cheap). Our motor cables are 7.3mm outside diameter and weigh 130g/m. Dave's selection is 9.5mm outside and weighs 243g/m.

David Smith
Tue 24 April 2007, 18:27
Well I bit the bullet and ordered my cable. cost was close to $600.00 (ouch). The problem I ran into is there is no "middle of the road"
either the cost is sky high or the cable is not flexable and you have to buy it in bulk. after talking to the wife I decided to get the
better cable and not have to worry about problems down the road. It may not be cheap but I want/need a high quality dependable
machine and if built right I belive MechMate will be both.

Gerald thanks again for all you do.

David

Gerald_D
Tue 24 April 2007, 23:07
Here is a reply I got on another forum:

"I use Alpha wire from Mouser (for motors, part no. 602-2424C-500 - spec (http://www.alphawire.com/pages/mouser.cfm?pn=2424C)). It is 18 gage, 4 wire with a foil shield and a drain wire. Prices have gone up to about $.75 per foot plus shipping. It was about $.50 a year ago.

I buy it in 500' reels and I sell it to my customers at $1.00 per ft plus $8.60 shipping in the US.

Robert Colin Campbell
Bob Campbell Designs
www.Campbelldesigns.net (http://www.Campbelldesigns.net)"

David Smith
Wed 25 April 2007, 22:45
Gerald,
glad to see you found a cost efective solution for the states, as for me I have already place my order.
Would I have bought what you have found yes, do I regret buying what I did no. I don't know anyone
that has ever regreted buying quality.

Thanks
David

Gerald_D
Wed 25 April 2007, 23:26
David, I am not recommending the Alpha/Mouser/Bob Campbell option, merely quoting it. That wire is not rated for continuous flexing - Mouser lists it in their catalog as "Communication and Control Cable". Sure, it is going to work for a lot of guys, but it will stop working looong before yours does. http://www.mechmate.com/Forum/clipart/happy.gif

Cables for continuous flex all have braided screens, which are more expensive to produce than simply wrapping a foil tape around the inner cores. The foil tape is the weak point for flexing - it eventually cracks into flakes (or the metal rubs off the Mylar) and the screen effect is lost. Snag is, one starts to get intermittent interference problems when the cable breaks down. This is how to finish the ends of a cable with Mylar foil screen:

http://www.mechmate.com/Forum/messages/3347/921.jpg http://www.mechmate.com/Forum/messages/3347/922.jpg

The risk to the driver is actually not more than with a braided screen cable. To assess the quality/flexibility of the inner cores, one has to look at how fine the copper strands are. Today's Gecko 203V driver is supposed to tolerate a wire break much better than the earlier versions, so it might be possible to consider cheaper cables these days? (Most drivers used to blow when a cable got broken).

Gerald_D
Thu 26 April 2007, 10:56
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
Fri 11 May 2007, 15:41
Will LAPP ÖLFLEX-CLASSIC-110CY do?
Unfortunatly it costs ?4.40 pr. meter for 4 lead .75mm and ?6.97 for 1.5mm (1mm not available) 'locally' (from Sweden) + taxes and shipping...

Håvard
Fri 11 May 2007, 16:20
Will something like this work?

http://cgi.ebay.com/Cable-22-AWG-4-Conductor-PVC-Jacket-Shielded-100-ft_W0QQitem Z190068050312QQihZ009QQcategoryZ4667QQrdZ1QQssPage NameZWD1VQQcmdZViewItem (http://cgi.ebay.com/Cable-22-AWG-4-Conductor-PVC-Jacket-Shielded-100-ft_W0QQitemZ190068050312QQihZ009QQcategoryZ4667QQr dZ1QQssPageNameZWD1VQQcmdZViewItem)

Gerald_D
Sat 12 May 2007, 03:24
I need to get home before I can answer your question properly - the internet in this hotel is pretty bad.

Håvard
Sun 13 May 2007, 02:14
Hi,

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
Sun 13 May 2007, 11:40
I am sitting at Johannesburg airport right now, due to a lot of bungling by Delta airlines - I believe that Delta is run by the same people that give bigger numbers to smaller wires http://www.mechmate.com/Forum/clipart/angry.gif

Håvard
Sun 13 May 2007, 12:22
Airports are such great fun... Always have a few books with you when airports are involved.

Anyway, isn't the cables for the steppers a bit overkill? 1.5mm^2 is used here for 10A 220V electrical (2200W). On the steppers you have 300VA powersupply split on four steppers which are then split into four wires (Or 2A 70V on each motor max(140VA)) and you are still using 1.0mm^2 on each wire. I don't know how the power is distributed on those four wires but somehow I doubt they are all running 2A continuous.

Anyone thought on how long those none braided alu foil shielded cables are going to last? Are we talking months or year of continuous use?

Frank D
Sun 13 May 2007, 12:56
An FYI for anybody that cares, lol. AWG sizing has to do with the number of passes through the dies to get the wire. For example, 0 wire requires less draws that 30 AWG. (Think Solid wire here). Most AWG stranded wire is made using 26-30AWG strands. The result is building a stranded wire to the nominal gage's area in circular mil. Also, for gages 5-14, the wire gauge is effectively the number of bare solid wires that, when placed side by side, span 1 inch. In other words, 8 AWG is roughly 1/8" in dia.

And airplanes are a blast, so much so that I stopped flying commercial and bought my own (I loathe US Airlines, no concept of service anymore).

Gerald_D
Mon 14 May 2007, 01:53
Håvard, The recommended motor wire size of 1.0mm2 is based on the fact that the Gecko 200 series drivers are capable of 7 Amps each. You could use a thinner wire for 2 Amp motors, but the price does not come down so much.

Another place to search for cables is with the guys in the music and sound reproduction industry - even people doing high quality home installations.

Gerald_D
Mon 14 May 2007, 09:48
http://www.mechmate.com/Forum/messages/3347/15225.gif

Håvard
Mon 14 May 2007, 12:02
Will try some different sources for cable. If you pay $1.65 for a meter, I should be able to find something that cost less $10 for a meter which is the best price I've found so far.

Gerald_D
Mon 14 May 2007, 12:24
My wife and I are planning to visit your country in June next year - should we bring some cable? http://www.mechmate.com/Forum/clipart/happy.gif

Gerald_D
Mon 14 May 2007, 12:29
Have you tried this company?:

http://www.miltronic.no/

soulvoid
Sat 19 May 2007, 11:14
Checked with them, turns out that the ÖLFLEX CLASSIC 115Y is an inexpensive cable compared to the ÖLFLEX CLASSIC 110Y that they stock. There is also ÖLFLEX 120CH which is a fraction less expensive. They wanted $$$ to cut from a roll, however directed me to local resellers. These however only sell to registered businesses.

I contacted Mariss who said you don't need a that thick cable, especially when not using the max output of the drives. We'll see what I can come up with.

soulvoid
Sat 19 May 2007, 16:53
Will cables with both braided and foil shield work?

Gerald D
Sat 19 May 2007, 21:55
I'm sure that that a double-shielded cable will work. The "inexpensive" 115Y sounds just right! :)

John Jasper
Thu 31 May 2007, 11:40
From the Mouser catalog, these are the prices for flexible control wire and the wire from Bob Campbell. Is the cost/quality difference worth the price differincail?

Alpha Wire XTRA-GUARD High Flex Cable 18AWG 4C SHIELDED 100ft $1560.36
Alpha Wire XTRA-GUARD Standard Flex Cable 18AWG 4C SHIELDED 100' SPOOL GRAY $1029.18

Bob Campbell
Alpha wire Multi-Conductor Communication and Control Cable 4C 18AWG 100' SPOOL $123.79

Gerald D
Thu 31 May 2007, 12:36
No, there will not be a ten-fold (plus) improvement in quality, reliability, performance, etc. We are not building a machine where we have to have 100.00% up time. If we were, then a lot of other components would have to have 10-fold cost increases.

Gerald D
Sun 03 June 2007, 10:27
Can someone tell me if the Porter Cable & Milwaukee routers have ground wires in their cords? ie. are the cords 3-core or 2-core?

Marc Shlaes
Sun 03 June 2007, 11:28
Gerald,

Both of those brands are 2-wire cords. I own both of them and physically checked. I was surprised by both. I expected them to be 3-wire. Why?

Marc

Gerald D
Sun 03 June 2007, 12:10
Thanks for checking Marc.

In the "cables" thread (this post and responses, were moved here) I am still saying 3-core cable for the routers....that is obviously wrong. 2-core screened/shielded cables will be easier to find than 3-core.

I was thinking that all metal casing tools still had a ground wire, but you have just confirmed this to be not true.

Marc Shlaes
Sun 03 June 2007, 12:17
What does screened and shielded actually mean? I am sure that if I had to ever replace a plug, which I have done to many American-made tools, I would find absolutely no screening or shielding (if that means metal). I would find standard rubber insulation for each conductor inside a rubber sheath housing all conductors. Maybe noise is minimized by twisting the conductors inside the sheath the way the conductors are twisted inside a CAT-5 ethernet cable. Don't know. Never completely stripped a tool power cord. I would believe that neither manufacturer is terribly concerned about noise. Is that your concern?

Gerald D
Sun 03 June 2007, 13:31
Crudely put; when long lengths of cable are bundled together, they start to talk to each other.

Screening/shielding stops this. It stops cables from emitting or receiving stray signals (interference). The router is not sensitive to incoming noise - because of its brushes it tends to emit noise. The wires from the pushbuttons are the most susceptible receivers. The stepper motor cables emit high frequencies.

Interference can be prevented by keeping parallel cable runs short, keeping cables well separated, or failing those, shielding/screening them.

Marc Shlaes
Sun 03 June 2007, 13:54
Is there and after market screen / shield that you can "lace" over power cords or would you simply replace the entire cord with one that is screened / shielded / grounded?

Gerald D
Sun 03 June 2007, 21:34
I doubt if practical "lacing" were available. Remember we also need flexibility, both of the screening and the inner copper cores.

If we wanted to save money in this area, we could consider having screens only on the susceptible signal (push-button) cable. Or only having expensive cables for the short sections that actually flex. Or moving the control box under the table. Each of these options carry risks.

John Jasper
Tue 05 June 2007, 07:27
Yes, copper braid sleeves are available to do this. But with anything copper these days it is not a cheap solution. It runs about $1.50USD/ft. I would invest that $1.50 into getting a better cable.

As for me, I am going to give it a go with:
Alpha wire Multi-Conductor Communication and Control Cable 4C 18AWG 100' SPOOL $123.79 Mouser Page (http://www.mouser.com/search/refine.aspx?Ntt=602-2424C-100)

Greg J
Sun 24 June 2007, 16:54
Well I bit the bullet and ordered my cable. cost was close to $600.00 (ouch). The problem I ran into is there is no "middle of the road"
either the cost is sky high or the cable is not flexable and you have to buy it in bulk. after talking to the wife I decided to get the
better cable and not have to worry about problems down the road. It may not be cheap but I want/need a high quality dependable
machine and if built right I belive MechMate will be both.

Gerald thanks again for all you do.

David

David,

I'm waiting on a quote from Hi-Tech Controls. I'm just not comfortable with the foil shield. A year from now (or more), I don't want to be trouble shooting intermittent wire problems.

Did you go with Hi-Tech? If you did, what did you buy for $600. That seems low for what I'm wanting to get.

Greg

Greg J
Sun 24 June 2007, 16:56
This is how to finish the ends of a cable with Mylar foil screen:

http://www.mechmate.com/Forum/messages/3347/921.jpg http://www.mechmate.com/Forum/messages/3347/922.jpg



Gerald,

Whats the proper technique for braided cable?

Greg

Gerald D
Sun 24 June 2007, 21:20
For braid, you don't need to fold it back for strain relief, or join on stronger wire. The braid is quite strong enough to be treated as any of the other cores. You crimp a terminal directly to the braid.

I put a thin heatshrink sleeve over the short bit of exposed braid, before it enters the terminal. And then a bigger heatshrink sleeve over the outer cable where the cores break out - this covers any stray braid "hairs" that may be peeping out there.

Greg J
Mon 25 June 2007, 06:17
Thanks Gerald,

Greg

Hugo Carradini
Mon 25 June 2007, 11:16
Hello Gerald and friends. I was wondering what is the best trick to cut the surface off a cable for making different connections, with out cutting the cables underside. ¿Do I have to be a surgeon?:confused:
Hope to be finishing soon my working area (Its been raining almost every day and had not time to finish roofing) so I can post new progress.:mad:

Gerald D
Mon 25 June 2007, 12:38
Welcome back Hugo!

I bend the cable over a finger in the one hand, and then use a very sharp knife to push down onto the tight skin of the cable with the other hand. First you need to drag the blade slightly so that the skin starts splitting under the pressure of the blade. Stop slicing/dragging while the skin splits, and the blade will stop at the next layer. Then roll the cable a bit over the finger to slice in from another angle - about 4 places around the cable and then the outer case breaks off at the knife marks.

bbreaker
Sat 25 August 2007, 03:05
I found a multicores cable, is it good for us ?

NEXANS LYFLEX B

and the link :

http://www.nexans.fr/eservice/navigation/NavigationFamily.nx?navigationId=126876#top

Gerald D
Sat 25 August 2007, 05:04
That cable looks very good.

bbreaker
Mon 03 September 2007, 01:44
Ok, I've got my wire, but some are Unshielded, is all wire necessary shielded ?

I think Motor, Spindle, can be shielded and other's ?

Michel

Gerald D
Mon 03 September 2007, 04:58
You might be lucky, you might not. I didn't take any chances, so I recommended all screened cables. Before, I did have some bad experiences with unscreened cables, and I personally won't take the chance to order some unscreened cables. But, if I have already purchased the cables, then I would try it.

jbmclain
Fri 07 September 2007, 21:01
Gerald, I have 2 phase Oriental motors w/ ( 6 wires).
I have come across some 7 conductor shielded 18 Ga stranded wire. Is this good or over kill?

Thanks
joe

Gerald D
Fri 07 September 2007, 21:44
Hi Joe

The drive (eg Gecko) will only accept 4 wires. You don't run all the motor wires all the way to the drive. With your motors you will only connect to 4 of those 6 wires.

Marc Shlaes
Sat 08 September 2007, 07:05
Gerald, What about the gauge?

Next question,

Would it be smart or dumb to run cable with extra wires. If a wire breaks, you have spares ready... or would you assume that since they are all flexing together, If one goes they are all about to go?

Gerald D
Sat 08 September 2007, 07:27
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."

Yes, if one wire is becomes faulty, dump the whole thing

Doug_Ford
Fri 05 October 2007, 10:28
For the past few days, I've been trying to locate a source for decent quality flexible cable. Good grief. I can't believe how hard it is to get someone to call me back with a price. Since I don't want to buy 500 feet of cable, they won't deal with me or they leave me hanging. I spoke with a salesman at the Lapp factory and he said they will sell short lengths of cable to distributors. Then when I contacted the local Carlton-Bates office, one salesman said he'd call back with a price. He never did. The next salesman said they only sell spools of wire. Yeah right.

I know that there are some small company owners that read this forum who deal in motors and circuit boards for CNC machines. Some have invested lots of time and money in R&D on their products. Maybe one of y'all would be interested in taking advantage of a business opportunity. I'm not suggesting that there is enough demand just from Mechmate builders to justify buying large spools of the cable we need but surely there are other CNC machine builders/owners seeking a source for small amounts of decent cable. There has to be some commonality in the types of cable we all desire. Heck, Lapp and Alpha don't sell that many different variations in continuous flex cables. I'd be willing to purchase cables with an extra conductor or maybe a larger guage if I had to. A seller could probably get by with a limited inventory in the beginning in order to get established as a dealer willing to sell short lengths and then expand the product line as demand increases.

However, if you want to get my order, you better hurry because I'm not the kind of guy that sits around on his butt waiting for things to happen. I'll eventually find a source and I'll post the contact info here for everyone else.

My next call will be to the regional sales manager for Carlton-Bates to let him know he has a lazy sales staff. If he doesn't care, maybe the vice president for sales at the Carlton-Bates Corporate headquarters will.

Marc Shlaes
Fri 05 October 2007, 13:31
Doug,

I really like the way you think! Keep it up.

Marc

garyc
Fri 05 October 2007, 16:11
Here is a link for you:
http://cgi.ebay.com/Stepper-Servo-Motor-Shielded-Wire-Cable-20awg-4cond-CNC_W0QQitemZ180165658579QQihZ008QQcategoryZ67000Q QssPageNameZWDVWQQrdZ1QQcmdZViewItem

Doug_Ford
Fri 05 October 2007, 19:24
Gerald,

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.

http://www.helukabel.de/index.php?lang=en&func=2p&func=2p&parentid=PG16&uparentid=PG1607&masterid=16320

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

dholtgrave@lapptannehill.com

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, 19:27
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, 20:02
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, 08:35
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, 19:24
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, 20:36
Good note Doug.
FYI
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
Sat 10 November 2007, 21:27
Thanks Sean. Luckily, I have enough cable to get out of the bending zone so if I need to splice some cheaper stuff in, I should be okay.

Gerald D
Sat 10 November 2007, 22:51
By fixing the cable chains on the drawings, I can now also start to give accurate cable lengths. A huge mistake is to cut the motor cables into 4 equal lengths - there is a big difference in the cable to the x-motor nearest the control box and cable to the z-motor.

Doug_Ford
Mon 12 November 2007, 17:06
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.