Extending cables

[Walker]

I have converted my Plasmacam table to use tracks instead of the boom. One of the cables is barely long enough, and the other is way too short. I have not been able to find cable like that used originally and need to make new cables. I have the right Molex connectors and pins. I have found similar cable, but without the shielded pairs. Is non shielded wire okay to use, or what cable is commonly used to wire the gantry?

Thanks,

[djreiswig]

Is there any markings on the cable sheath?

[Walker]

Yes, however it is unobtainable, and finding a direct replacement is proving difficult. The cable has a larger pair of power wires (18 gauge or so) with a braided shield, a group of 5 with shield and a group of 4 with shield, these are smaller, maybe 24gauge.

[robertspark]

the problem is plasmacam uses servos..... which have encoders on them.... which can be very high frequency pulses at low voltage driving low impedance (so they don't like noise).....

the frequency pulses through them depends on the encoder resolution.... but I would aire on the side of caution and try to locate a multicore shielded cable (even consider using a shielded twisted pair data cable.... it may work.... then again it may not.....). I would not use an unshielded cable for high resolution encoders

YMMV, just an opinion, do as you see fit. (in the UK we would search for a belden (a manufacturer) type of cable or a cy or sy type.... but I have no idea what you would call them in the us).... rs components would be one of many sources (plus a good local electrical wholesalers.... where you can have a chat over the counter (rare these days))

[adbuch]

I have converted my Plasmacam table to use tracks instead of the boom. One of the cables is barely long enough, and the other is way too short. I have not been able to find cable like that used originally and need to make new cables. I have the right Molex connectors and pins. I have found similar cable, but without the shielded pairs. Is non shielded wire okay to use, or what cable is commonly used to wire the gantry?

Thanks,

Here is a list of the parts required to make up your Plasmacam cables - compliments of Bill Klemm. Yes - you would definitely want to use shielded cable with proper termination for shield drain/ground wires.
David

Here is a list of part numbers and sources for cables, plugs, receptacles, pins and sockets needed to extend the existing cables, or make new cables for the tables: Z2, DHC, DHC2, 510.

1. Plug for controller – MOLEX p/n 39-01-2200, Plug and socket housing, receptacle, 20 position, 2row 4.2mm NEWARK p/n -56H7737 price each-$0.77.

2. Connectors for controller plug (above )NEWARK p/n WM2501-ND price ea. $0.43 DIGI-KEY p/n 39000039 $0.11,

3. Plug for the end of cables from controller to motor. 2 needed, MOLEX p/n 03-06-1152, NEWARK p/n 38C8703 price each $0.67.


4. Female crimp receptacle for WM2501-ND plug, MOLEX p/n 02-06-1132, NEWARK p/n 85C0027. Price each $0.06. Pack of 100 $6.00.

5. Receptacle for above cable, ( if making an extension to existing cable, mates with above WM2501-ND) MOLEX p/n 03-06-2152. NEWARK p/n 38C8719, price $0.58 ea. Two needed.

6. Male crimp connector for 03-06-2152 MOLEX p/n 03-06-2132, NEWARK p/n 85C0026 $0.09 ea.

7. NOTE. These crimp connectors need a special crimping tool to make a good crimp. Can be found on EBAY. Search for “ MOLEX Style CRIMP TOOL Wiring Harness Crimping Crimper Open Barrel 14-24 AWG” around $30.

8. Cable, shielded, Multi-Conductor, 9 Conductor, 24AWG, 100 ft. Manufacturers p/n 1012409 SL005 NEWARK p/n 03F4294, Price for 100 ft - $95.40. (can also use p/n 03F4292)

9. Cable Shielded Multi-Conductor, 2 Conductor, 18 AWG, 100 ft. Manufacturers p/n 2421C SL005 NEWARK p/n 89K8108 Price for 100 ft $77.61.

[adbuch]

Another option would be to simply purchase the main wiring harness from Plasmacam and use this to extend your existing main harness. In fact I did exactly that for one of my customers several years ago. He was wanting to run a separate rotary pipe cutter with his Plasmacam and use a single controller - so unplugging the cables from the motors/encoders on the table and plugging into the other set of motors/encoders on his pipe cutting setup.

I would recommend Belden for your shielded or shielded/twisted pair replacement cables - in fact that is probably what Plasmacam uses. I'll have to walk out to the machine shop later and take a look.
David

[adbuch]

I just checked, the cables are not marked with Belden, but have a part number as shown in my previous post with the list of part numbers and sources.
David

[Walker]

Finding the cable, even with that part number is difficult, as I donut need 250’ or whatever is on a spool. The multi core and different size wires is the stumbling block. I I see where that cable plus a shielded pair is used in lieu of the factory cable. Not much in the way of electronics stores here anymore, so it is all online now. In the end I decided to order The longest factory harness available and I will just do one splice. It should be here in a couple of days so I can finish up and get my Frankenstein table finished up.

Thanks for the help,

Walker

[adbuch]

Glad to hear you took my advise and ordered the Plasmacam main harness. This will save you some time, but it's still about about a 4 to 6 hour job to do it correctly. Let me know if you have any questions. Lots of small heat shrink tubing and soldering.
David

[djreiswig]

Can you buy the mating connectors and put them on the new cable and plug it into your old cable to make it longer? Or maybe it's just easier to solder them together.

[adbuch]

Can you buy the mating connectors and put them on the new cable and plug it into your old cable to make it longer? Or maybe it's just easier to solder them together.

Yes - that would be a possibility. The connector part numbers are listed in my previous post. The main wiring harness has a large single connector on one end that plugs into the controller, and then is split into two branches - one that goes to the X motor/encoder harness and one that goes to the Y motor/encoder harness. If the new harness was split/cut where it branches, then mating connectors could be installed (the equivalent gender to the shorter x and y motor harnesses) to effectively create two "extension cables". This will require the crimp tool and connector pins to accomplish, and will probably be more difficult to accomplish than using the "cut and solder" method - depending on the experience/skill level of the person doing the work.
David

[rdj357]

I am in the process of putting together a kit (including drag chain) to convert tables from boom to track. I will also have the longer harnesses. HOWEVER as others have mentioned, the cable is custom made by a manufacturer in Taiwan so short of paying a fortune to build a similar cable, the best way is with a shielded pair to power the motor and a separate shielded cable for the encoders and other circuts (limit switches.height sense, etc.)

This is in development so it may several months before I personally have them available.

[adbuch]

Robert,
Will you be offering the longer harness separately, or will it only be included in your complete kit?
David

[rdj357]

Robert,
Will you be offering the longer harness separately, or will it only be included in your complete kit?
David

I will offer it separately as well.

[adbuch]

Thanks Robert.
David