Make a Spigot for a Lightstand: Materials

I got a cheap E27 lamp socket holder with umbrella flash bracket from DealExtreme (http://www.dealextreme.com/p/single-e27-socket-lamp-bulb-holder-flash-umbrella-bracket-92060) that I intended to use for an E7 type screw in flashlight.
When it arrived I was quite happy with it, but it was lacking one thing: The Spigot.

A Spigot is a pipe like device that can be screwed on to a light stand or tripod on which subsequently a light can be clamped. At one end it has an m4x20 (4 mm 20 threads/inch) nut and at the other end a slightly bigger nut (or screw if you have the male variety).
The M4x20 is the classic photo tripod screw.
Spigot's will not break the bank, they are to be found for about 6-10 euro's, but that is still a lot of money for what is basically a piece of brass, but they are not readily available where I live.

As it was a weekend (shops closed) and I had stuff laying around, I thought it should be easy to make one myself. As I only intend to use it on a regular tripod, I opted to only put one nut in there.
The M4x20 is not a common size here Europe as it is an american/AngloSaxon size. The threading on the bolts and nuts here is a bit tighther, but they are available if you look for them. I was in luck though as I had recently brought some from Singapore. However, they may easily be obtainable in your neck of the woods.

Anyway, here is the list of materials:
An M4x20 nut
About 5 cm brass/copper pipe 15mm diameter
A 15 mm end cap for that pipe
About 5 cm of 12 mm brass pipe
A 12 mm end cap (optional)

Tools
Saw
dril with 5mm dril bit
solder
solder torch
S39 soldering liquid

Steps: What we will be doing is the attach the nut in/on/to the 15 mm pipe and solder it there. We will put on an end cap with a hole in it that covers the nut with exception of where the screw goes. We will insert a smaller piece of pipe for extra support and that will be all soldered together. Then as a finishing touch, we will put on a small end cap at the other end.

For ease of understanding I added a little 'construction schedule'
Basically it is a piece of pipe with a smaller piece inserted in it, a not at one end and then two caps covering the ends. One of the caps has a hole so a bolt can be screwed into the nut

The construction may vary a bit, depending on what kind of nut you have. I had a square one, so I had to make a square recess, If you have a round nut, you may be able to fit it in the 15 mm tube

Step 1: Make a Spigot for a Lightstand: Fitting the Nut

Cut of a piece of the 15 mm pipe with a pipe cutter.
The length depends on the lampholder you are working with. It needs to go in all the way and then have about 1 cm extra to attache the pipe cap. As a rule, these are a bit too thick to disappear in the lampholder, so they will stick out.

If you plan to also cap the 12 mm pipe, you need to cut off an extra cm off of the 15 mm pipe (to make space for the 12 mm cap.
Then cut a piece of 12 mm pipe that is about 1 cm longer than the 15 mm pipe

If you have a square nut like I did, then you need to file 4 corners in the 15 mm copper pipe as can be seen in the picture. Make sure these are not too deep: the nut must be flush with the surface of the 15 mm pipe (2nd picture)

Make sure the corners of the nut do not stick out of the pipe. If necessary, file them down a bit.

Step 2: Make a Spigot for a Lightstand: Fitting the Hole

Now you need to drill a hole in the 15 mm end cap. This hole needs to be at least 5 mm (to allow space for the 4mm bolt).
It is probably a good idea though to make the hole at least 6 mm to allow for the fact that the nut and the hole may not fully align in their center.

Once you have done that, assemble the 15 mm pipe, the nut and the end cap to see if you are on target and that the hole in the nut is fully visible.

Try with a proper bolt to see if it really goes in without problems

Step 3: Make a Spigot for a Lightstand: Soldering

First: clean the parts with a bit of fine sandpaper or a brillo pad.

The easiest way to solder this together is to use preformed solder rings that are specifically made for pipe soldering, but you can also shape a ring yourself.

Do as follows:
Put the nut in its place on the 15 mm pipe
insert a slder ring in the 15 mm end cap
put the endcap on the 15 mm pipe, covering the nut.
again, make sure that the holes in the endcap and the nut line up (they should if everything was centered to begin with.
Put it down on its end cap
insert a 12 mm solder ring in the 15 mm pipe (it will rest on the nut)
Insert the 12 mm pipe in the 15 mm pipe

If you want, you can now place a 12 mm end cap (filled with a solderring) on the protruding end of the 12 mm pipe. I ended up NOT doing that for the simple fact that my local hardware store was out of 12 mm caps.

In order to have a sturdy contraption for soldering, clamp the assembled parts in a metal clamp (like the ones you use for clamping glued parts together) If there are any plastic protectors on the clamp, remove those.

apply some flux around the end cap(s)

Take a flame torch and gently heat the entire piece from all sides until the solder is melted. To make sure, you can touch the pipe with a piece of solder (preferably around the 15 mm cap): it should melt and disappear in between the pipe and the cap. Some times this isn't even necessary if you see the solder from the rings well up from the pipe- end cap connection.

Switch off yr flame and let the copper cool down.

It should look like the picture, it will most likely be pretty dirty

When it has cooled off, test it with the M4x20 bolt. Eveything should be ok.
if you really used a lot of solder there might be the risc that some has spilled on the thread of the nut, but screwing in the bolt a few times should remedy this.

Now clean the nut (with brash polish, or some fine sandpaper)