# Bi-pin / High temp socket help



## EvilPaul2112 (Feb 5, 2011)

What methods are you using to retain your bi-pin lamps in the high temp sockets (KIU) without falling out? I have been recently building another incan and found the bi-pin lamps pretty loose in the socket.


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## Darien (Mar 18, 2011)

The only method I have used is to slightly widen the pins on the bulb to make the fit in the socket more secure, it works.


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## HotWire (Mar 19, 2011)

I bend a small bump in the pin. I use 2 pair of small long-nose pliers on each pin so I don't stress the envelope.


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## Stephen Wallace (Mar 20, 2011)

You could try tinning the pins with solder to make them a little wider.


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## Darien (Mar 20, 2011)

Stephen Wallace said:


> You could try tinning the pins with solder to make them a little wider.



Sounds like a good idea, better than widening out the pins.


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## ^^Nova^^ (Mar 20, 2011)

I use only G4 bulbs in one of the holders and G6.5 in another. The bigger bulbs make the holes too big for the smaller ones to reliably stay put.


Cheers,
Nova


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## Stephen Wallace (Mar 21, 2011)

Agreed. 

I was using WA1185s (G4), but wanted to try an MR16 (G6.35) - just because I could really, with no real intention of sticking with the MR16 - only to find that the socket no longer gripped the G4s. Then you find yourself having to make fixes like this. 

One of the strengths of sockets is that they do let you experiment with different types of bi-pin bulbs, but the contacts aren't as 'springy' as I had assumed, and don't return back 100% after using the largest pin size. 

If your intention is to use a G4 bulb, probably best just to experiment with other G4 bulbs, and vice versa with G6.35 bulbs.


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## sterr11 (Mar 21, 2011)

I have successfully retentioned the socket by going through the back with a small watchmakers screwdriver and bending the bulb retainer back into position.


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## Justin Case (Mar 21, 2011)

The Welch-allyn bi-pins use a nickel-plated iron wire for the leads. Nickel plate can be easy or hard for solder to stick, depending on several factors. Simplest thing is to try it out, but if the solder doesn't stick, you might need to find flux that is tailored for nickel.


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## Stephen Wallace (Mar 21, 2011)

sterr11 said:


> I have successfully retentioned the socket by going through the back with a small watchmakers screwdriver and bending the bulb retainer back into position.


 
Knowing my luck with these things, I'd probably shove the screwdriver blade straight through the wires!


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## JimmyM (Apr 3, 2011)

Stephen Wallace said:


> You could try tinning the pins with solder to make them a little wider.


 Solder melts around 190-230C. You may end up soldering your bulb into the socket.


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## eebowler (Jun 25, 2011)

I stuffed folded strips of foil in the hole to take up space and it works somewhat but, the bulb still shifts out of place if the light is knocked. Maybe I need more foil!


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## JimmyM (Jun 27, 2011)

eebowler said:


> I stuffed folded strips of foil in the hole to take up space and it works somewhat but, the bulb still shifts out of place if the light is knocked. Maybe I need more foil!


 The foil may have just torn. It's not all that strong. You could try using a thicker/stronger foil. You could try de-laminating the copper foil off a PCB that has thick copper cladding. You just go outside (fumes) with a blank/copper clad PCB and a propane/butane torch and heat up the foil so it ruins the epoxy used to adhere it to the board. Then just peel it off and scrub it to clean it. Just a thought. I've never tried it. I KNOW I've de-laminated PCB traces/pads on boards I've soldered too much.


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## LuxLuthor (Jun 28, 2011)

It's not too hard to remove the top, stretch the spring to give more tension, replace top and re-anchor pins with a spot of epoxy underneath. See larger photo I took a while back.


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