Making DMX Cables

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doncolga
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Making DMX Cables

#1 Post by doncolga »

Hey,

I think I have a POS solder gun, or maybe I'm doing something wrong. The plastic on the DMX connectors is melting before the solder is and I can't remove the wires already there. Plastic melting to the point that the pins are moving and getting out of alignment. Is this characteristic of a crappy gun or something I should correct?

Thanks,

Donny
Donny Collins
Built:
Two 18" Tuba 30's 3012 LF
Two 26" Tuba 30's Lab 12
Two OmniTop 12's DL 2512 (Melded Array)
Presonus Studio One DAW
Harrison Consoles MixBus 32C DAW

Grant Bunter
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Re: Making DMX Cables

#2 Post by Grant Bunter »

Have you got an ordinary soldering iron? Not a gun.

If the pins are moving due to the heat, I'd say you have POS connectors.
If your DMX ins and outs are 3 pin, get some neutrik XLRs instead.
Cut off the old connectors and put on the new ones, you'll lose a couple of inches in lead length.

edit:
Tin the wires from the cable and the parts they go onto on the XLR's before joining together, that should cut down plastic melting.
And continuity check with your DMM when done, making sure you have no shorts from one pin to another.
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" KL3010LF , 2 x 28" 3012LF.
WH8: x 6 with melded array wired series/parallel.
Bunter's Audio and Lighting "like"s would be most appreciated...

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doncolga
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Re: Making DMX Cables

#3 Post by doncolga »

Grant Bunter wrote:Have you got an ordinary soldering iron? Not a gun.

If the pins are moving due to the heat, I'd say you have POS connectors.
If your DMX ins and outs are 3 pin, get some neutrik XLRs instead.
Cut off the old connectors and put on the new ones, you'll lose a couple of inches in lead length.

edit:
Tin the wires from the cable and the parts they go onto on the XLR's before joining together, that should cut down plastic melting.
And continuity check with your DMM when done, making sure you have no shorts from one pin to another.
I guess I have an iron instead of a gun...shows how much I know...haha. I'd thought about just getting new connectors too. Can you recommend any particular Neutriks? Looks like there are many different varieties. I'm making up about 12 short cables (about 1 foot each). This will make my lighting rig much neater and faster to setup and breakdown. I'm really looking forward to doing this as it's been a while since I've used my whole lighting rig. This will put me at 20 DMX lights total and I estimate about 10-15 minute setup time.

Thanks!

Donny
Donny Collins
Built:
Two 18" Tuba 30's 3012 LF
Two 26" Tuba 30's Lab 12
Two OmniTop 12's DL 2512 (Melded Array)
Presonus Studio One DAW
Harrison Consoles MixBus 32C DAW

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Bill Fitzmaurice
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Re: Making DMX Cables

#4 Post by Bill Fitzmaurice »

doncolga wrote: Plastic melting to the point that the pins are moving and getting out of alignment. Is this characteristic of a crappy gun or something I should correct?
Not enough wattage. It takes so long to heat the metal that the plastic melts.

Grant Bunter
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Re: Making DMX Cables

#5 Post by Grant Bunter »

No worries Donny,
Just get the cheaper ones.

http://www.ebay.com.au/itm/12-Pack-Neut ... 2d1&_uhb=1

Like these will be fine, see if you can get some locally for similar pricing.
And the male ones...
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" KL3010LF , 2 x 28" 3012LF.
WH8: x 6 with melded array wired series/parallel.
Bunter's Audio and Lighting "like"s would be most appreciated...

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doncolga
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Re: Making DMX Cables

#6 Post by doncolga »

Bill Fitzmaurice wrote:
doncolga wrote: Plastic melting to the point that the pins are moving and getting out of alignment. Is this characteristic of a crappy gun or something I should correct?
Not enough wattage. It takes so long to heat the metal that the plastic melts.
The one I have is 30 watts. What wattage should I look for?

Thanks!

Donny
Donny Collins
Built:
Two 18" Tuba 30's 3012 LF
Two 26" Tuba 30's Lab 12
Two OmniTop 12's DL 2512 (Melded Array)
Presonus Studio One DAW
Harrison Consoles MixBus 32C DAW

Bruce Weldy
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Re: Making DMX Cables

#7 Post by Bruce Weldy »

This is the one I have - I love it. Variable heat. Turn it up to 5 for speaker cable, around 4 for the smaller stuff.

http://www.amazon.com/Weller-WLC100-40- ... B000AS28UC

Always tin the wire and the connector first. Always make sure the tip is clean by wiping it on a wet sponge. Then connections go fast and you won't melt the plastic.

And yes.....use the Neutrik connectors.

6 - T39 3012LF
4 - OT12 2512
1 - T24
1 - SLA Pro
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

byacey
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Re: Making DMX Cables

#8 Post by byacey »

Lot's of how-to soldering tutorials tell you to heat the work first before adding the solder. What they don't mention is a little bit of wetting with molten solder greatly increases the heat transfer between the soldering tip and the work piece to be soldered.

When you tin the barrels on the connector, touch the iron tip to the barrel , and instantly add a little tiny bit of solder to the tip where it's contacting the barrel; when it's warm enough, the solder will flow into the barrel by capillary action. This allows for faster heat transfer.

Some crappy connectors have some sort of poor plating that doesn't take solder well. Perhaps this might be part of the problem you are experiencing, and supports the case for buying quality connectors.
Built
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CoronaOperator
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Re: Making DMX Cables

#9 Post by CoronaOperator »

Grant Bunter wrote:No worries Donny,
Just get the cheaper ones.

http://www.ebay.com.au/itm/12-Pack-Neut ... 2d1&_uhb=1

Like these will be fine, see if you can get some locally for similar pricing.
And the male ones...
Those are what I use for making dmx cables except I prefer the black ones like these.

It really, really helps if you pre-tin your wires. Touch the wire to the solder gun/iron and hold the solder to the wire, not the soldering iron tip. When the wire is hot enough, the solder will flow into the strands. Do all 3 wires before you attempt to solder to the xlr connector. Use a vice or a helper to hold the xlr connector. Hold the wire into the slot of the xlr connector with one hand then touch the soldering iron to the wire with the other hand. When it gets hot enough the solder will not only melt but flow into the slot on the connector. Remove the heat and hold the wire steady (blowing helps) until the solder freezes again. Make double sure that you put the sleeve of the xlr cable on the cable before you solder your wires. You're allowed to forget on one end but once both ends are soldered you'll realize what you forgot to do!
Built:
17" width 10" driver Autotuba
2 x 29" width dual Lab12 Tuba60
6 x DR250 2510/asd1001
In progress:
2 x DR250 2510/asd1001
For best results, point the loud end of the array towards the audience

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Tom Smit
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Re: Making DMX Cables

#10 Post by Tom Smit »

Nice "how-to". :clap:
TomS

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Harley
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Re: Making DMX Cables

#11 Post by Harley »

Image
I spotted these at Leland's and used them to solder up 8 sets of crossovers whilst there. These are a must because they can hold wires/parts togther in a hands free fashion and being stainless steel, the solder does not stick to them. They also act as a heat sink ( so long as you don't squeeze onto the cable sheathing - see below ) .

Anither trick I learned from my avionics-tech son was to use small plastic cable ties on cable. This is esepically handy whne trying to hold two wires together and at the same time solder them to a pin or connector. The cable ties offers two advantages, one; being plastic it absorbs heat at the same rate as cable sheathing and unlike using a metal heat sink pver the sheathing, won't bare the wire, and two; the tail of the cable time can be gripped and use as a handle to accuratley guide the cables/parts into place and hole them without scolding your fingesr.

I'll post a demo later when it becomes daylight ( 4:00am here and wide awake getting over jet lag )
ImageSemi-retired: Former Australia and New Zealand Authorised BFM cab builder.

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Tom Smit
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Re: Making DMX Cables

#12 Post by Tom Smit »

Cool! Thanks Sam/Leland/Harley.
TomS

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