Gluey stuff for Molex KK connectors

[Newmarket]

Depeneding on the motherboard somewhere between 30 and 60.

Cheers

Ian

I see. So quite a few. I think that frame type solution would still be the norm' solution for commercial production at that scale ?
I'd be prepared for some wear'n'tear from the connector pins.

 

[ruffrecords]

I see. So quite a few. I think that frame type solution would still be the norm' solution for commercial production at that scale ?

I agree 100% but this is just me in my workshop at the bottom of the garden

I'd be prepared for some wear'n'tear from the connector pins.

I have toyed with the idea of rationalising cables. However these are all screened audio signals, either 2 pin unbalanced or 3 pin balanced. If anyone knows of a decent PCB mounting multipin connector suitable for these type of cables I would be glad to hear about it.

Cheers

Ian

 

[Cyril Jones]

Your board is rather large however a 15mm thick piece of soft foam held onto the connectors once they are in place with a piece to 6mm ply or similar should be a great help. Hold the board in place with GAFFA tape or clips. turn over, solder only on pin on each connector. Once done straighten connectors and complete the task.
For pcb's same approach. begin with diodes followed by resistors gradually building up pcb with the larger components.
The turn over jig was not a favourite with our assembly ladies for smaller boards, say up to 250mm square. They became so dexterous they simply held the board to the foam, upturned it and held it to the sponge with a finger of the hand feeding the solder to the iron. Thousands all sizes assembled this way. before machine assembly.
Ladies would load as many as 30 small pcb's to about 6 larger types on an assembly jig.
To assemble a jig take a couple of 40mm pieces of square wood sufficient to allow wire ends to hang loosely, rebate one corner on each along length, say 4mm and fix to a base placed rebate uppermost to receive the board/s held aloft over the base . Of course spacing between supports would be relocated depending on pcb dimensions. When ready sponge on top and turn over and as above. Many boards may be assembled simultaneously adding same value component to each board in turn. Some of my small Helios boards use the same approach.

For home use and ease panel pins tacked into the supports might be in order protruding 4mm above the supports instead of the rebate, quick and simple.

Cyril

 

[industrialarts]

Depeneding on the motherboard somewhere between 30 and 60.

Cheers

Ian

If it were me, I have three tricks (other than the solder one pin). You could try Tacky Glue - that's what it's called here in the States, it is a quick drying hobby glue, dries fairly soft. Used to tack things in place, believe it or not. Two - mini hot glue gun. The garden variety glue stick is low temp and easy to work with, can remelt with soldering iron, easy to remove later. The mini gun makes it easy to just place a small drop. And Three is what I believe was already mentioned - Poster Tack. This stuff is invaluable in my shop. You know those nuts that are out of reach? A pinch on the end of the long phillips, push the nut on and you can reach about a foot away. Pretty easy clean up for the most part, sometimes gets a little stubborn but it never seems to harden. I bought some at the Dollar Store about a decade ago and am still using it.

Hope one of these works for you. Cheers

 

[Newmarket]

I agree 100% but this is just me in my workshop at the bottom of the garden

Understood. I don't really like those racks personally. I guess a lot depends on how many of these boards you envisage making. And I see that Cyril Jones has offered some detailed advice.
Personally I'd likely go with the "Tiny drop of glue" on the nylon base to hold in place while fixing one pin - make sure they are all true to the board (oddly satisfying) - then solder up.

I have toyed with the idea of rationalising cables. However these are all screened audio signals, either 2 pin unbalanced or 3 pin balanced. If anyone knows of a decent PCB mounting multipin connector suitable for these type of cables I would be glad to hear about it.

I've looked at this previously and have to say that I don't know of a better connector solution.
I generally use 3pin 2.54mm friction lock KK headers. Pins designated to correspond to XLR / TRS ie
Pin 1 = X / S
Pin 2 = L / T
Pin 3 = R / R

Before anyone shouts, the 'Pin 1' connection is often not used eg where screen is properly terminated to chassis but I use 3 way in any case for adaptability / test etc.
Similarly with power connection I use Pin 1 for 0V although it's tempting to use the centre pin for that.
But I settled on Pin 1 - "Screen" / 0V or GND in all cases - means I always know where I can ground a 'scope etc.
Along the same lines there are some nice JST connectors with good (but £££s of course) hand tooling. But they are a bit more fiddly ime and tbh less easy to handle when you want to 'flick' a crimp out of the housing to modify / correct a connection
Avoid the very small JST family (I can't recall the names right now). Simply not reliable enough. Might be okay if you get everything correct and fit it once. After that - issues ! Sounds crazy I know but I had this problem on a commercial (non-audio) product where reliability was crucial. Unfortunately the pcb on a bought in component used these tiny connectors for the USB connection. Needlessly tbh as the pcb was large enough to take larger.
Taking advice from a local cabling subcon we used - answer was basically -"yeah that's what those are like. Everyone ends up dropping glue into the crimp housing" !

 

[ruffrecords]

Your board is rather large however a 15mm thick piece of soft foam held onto the connectors once they are in place with a piece to 6mm ply or similar should be a great help. Hold the board in place with GAFFA tape or clips. turn over, solder only on pin on each connector. Once done straighten connectors and complete the task.

Yes, it is the largest board I use. Basically a backplane that caters for 6 or 12 channels. So there are mic and line ins, direct outs, one or two fader in/out Molex connectors per channel. I think I have a piece of soft foam left over from some packaging. I shall give it a try

For pcb's same approach. begin with diodes followed by resistors gradually building up pcb with the larger components.

Smaller PCBs I am OK with. I build exactly as you describe. They are small enough I can hold a Molex in by hand and turn the board over to tack one pin, usually without burning a finger.

The turn over jig was not a favourite with our assembly ladies for smaller boards, say up to 250mm square. They became so dexterous they simply held the board to the foam, upturned it and held it to the sponge with a finger of the hand feeding the solder to the iron. Thousands all sizes assembled this way. before machine assembly.
Ladies would load as many as 30 small pcb's to about 6 larger types on an assembly jig.
To assemble a jig take a couple of 40mm pieces of square wood sufficient to allow wire ends to hang loosely, rebate one corner on each along length, say 4mm and fix to a base placed rebate uppermost to receive the board/s held aloft over the base . Of course spacing between supports would be relocated depending on pcb dimensions. When ready sponge on top and turn over and as above. Many boards may be assembled simultaneously adding same value component to each board in turn. Some of my small Helios boards use the same approach.

For home use and ease panel pins tacked into the supports might be in order protruding 4mm above the supports instead of the rebate, quick and simple.

Cyril

Good stuff. Thanks Cyril.

Cheers

Ian

 

[ruffrecords]

Understood. I don't really like those racks personally. I guess a lot depends on how many of these boards you envisage making. And I see that Cyril Jones has offered some detailed advice.
Personally I'd likely go with the "Tiny drop of glue" on the nylon base to hold in place while fixing one pin - make sure they are all true to the board (oddly satisfying) - then solder up.

I tried the drop of glue method last week and it worked really well.

I've looked at this previously and have to say that I don't know of a better connector solution.
I generally use 3pin 2.54mm friction lock KK headers. Pins designated to correspond to XLR / TRS ie
Pin 1 = X / S
Pin 2 = L / T
Pin 3 = R / R

EXACTLY the same as my standard pin out.

Before anyone shouts, the 'Pin 1' connection is often not used eg where screen is properly terminated to chassis but I use 3 way in any case for adaptability / test etc.

Pin 1 does get used on my mic inputs to complete the phantom power route to the mic input XLR. I still use twin screened for internal balanced wiring with the screen connected to chassis at one end

Similarly with power connection I use Pin 1 for 0V although it's tempting to use the centre pin for that.

But I settled on Pin 1 - "Screen" / 0V or GND in all cases - means I always know where I can ground a 'scope etc.
Along the same lines there are some nice JST connectors with good (but £££s of course) hand tooling. But they are a bit more fiddly ime and tbh less easy to handle when you want to 'flick' a crimp out of the housing to modify / correct a connection
Avoid the very small JST family (I can't recall the names right now). Simply not reliable enough. Might be okay if you get everything correct and fit it once. After that - issues ! Sounds crazy I know but I had this problem on a commercial (non-audio) product where reliability was crucial. Unfortunately the pcb on a bought in component used these tiny connectors for the USB connection. Needlessly tbh as the pcb was large enough to take larger.
Taking advice from a local cabling subcon we used - answer was basically -"yeah that's what those are like. Everyone ends up dropping glue into the crimp housing" !

I was toying with the idea of trying JST connectors but I don't think I will bother!!

Cheers

Ian

 

[Newmarket]

I was toying with the idea of trying JST connectors but I don't think I will bother!!

Just to be clear / fair for anyone reading this - JST are fine generally with nice, if expensive, tooling.
But I found the smallest pcb crimp type are just too unreliable to withstand any significant connection cycling.

 

[ruffrecords]

Just to be clear / fair for anyone reading this - JST are fine generally with nice, if expensive, tooling.
But I found the smallest pcb crimp type are just too unreliable to withstand any significant connection cycling.

Amphenol do a nice PCB mounting mini 4 pin XLR but they are over £9 each!

Cheers

Ian

 

[ToneShack]

I have a motherboard onto which I need to solder about fifty 2 way and 3 way Molex 0.1 inch pitch headers. It is a pain to do them one at a time so I was wondering if there is some kind of tacky fluid I could use just to hold them in place when I turn the board over to solder them. Any ideas?

Cheers

Ian

I use one of those grey artists erasers. The kind that are like play dough. It sticks good, and doesn't leave residue.

 

[sodderboy]

That artists eraser sounds similar to poster tack, which I use all the time. No residue and it's re-usable which is key. I'll look into the eraser. There is also a construction product that is similar, I forget the name. I use it to keep stones in place when I am doing lapidary work. That might be artists eraser, I will see if it erases.
Another stay-put! material in general is foam shelf liner on a roll, the one that looks like a net. I have a layer on my bench so stuff will not slide or bounce. Great stuff!
Mike