40 gauge wire

[sp org div]

Sorry for the big azz image, but hey, at least you can see it.   

So, How do You terminate 40 ga wire? 
I have been using small screw type terminal blocks for my signal wires like this (I think these were 36 ga):


Total PITA  ...but the new signals are now using the even smaller wire size.  Haven't been able to find a compression type that goes that small at Mouser or DigiKey so far....  Maybe I can find a #2 washer so the screw head doesn't twist off the end of the more delicate wire.  Only other thought that comes to mind is to mount a larger solid wire on the terminal block with a quarter inch hanging out, and then solder the signal lead wires to that.  I don't want to solder them to anything, let alone under layout.

Jeff
http://espeeoregondivision.blogspot.com/

[peteski]

40 AWG is a mighty fine wire!

Yes, soldering it to a short length of a bare thicker wire would be a valid option.  I usually use a piece of PC board glued to some base as a junction area and then solder the thin wire and thicker wire to the copper cladding but it seems that you prefer to be able to easily detach them.

[nkalanaga]

Soldering them to brass washers should work fine.  If you have some brass sheet you can make your own, in any shape, and have more room for soldering.  A rectangular shape would allow for a screw hole in one end and a soldering tab on the other, keeping the wire away from the screw entirely.  Cut the end of the hole and you'd have a basic slip-on connector that would work with your terminal strip.

[jdcolombo]

Agree on soldering either to a thicker piece of wire or directly to a washer or a spade connector.

A more complicated option: cut a piece of one-sided PC board about 1" wide and however long your need.  Cut several "slots" across the copper at 1/4" intervals, creating separate "pads" that are 1/4" x 1".   Screw the board to the underside of the layout near the terminal block you will be using.  Solder the 40-ga. to one end of a pad, and a thicker wire to the other end, and use the thicker wire for the terminal strip.

Why do it this way?  Very thin solid wire will break pretty easily.  Using the  PC board as an intermediate step means that you will never be flexing the 40-ga. stuff - only the thicker wire will be flexed when screwed to the terminal block (and unscrewed for troubleshooting purposes).  If you solder the 40-ga. wire directly to a spade lug or a washer, you run a much higher risk that the joint will break as you flex the wire to install the washer or lug in the terminal block.

John C.

[peteski]

Agree on soldering either to a thicker piece of wire or directly to a washer or a spade connector.

A more complicated option: cut a piece of one-sided PC board about 1" wide and however long your need.  Cut several "slots" across the copper at 1/4" intervals, creating separate "pads" that are 1/4" x 1".   Screw the board to the underside of the layout near the terminal block you will be using.  Solder the 40-ga. to one end of a pad, and a thicker wire to the other end, and use the thicker wire for the terminal strip.

Why do it this way?  Very thin solid wire will break pretty easily.  Using the  PC board as an intermediate step means that you will never be flexing the 40-ga. stuff - only the thicker wire will be flexed when screwed to the terminal block (and unscrewed for troubleshooting purposes).  If you solder the 40-ga. wire directly to a spade lug or a washer, you run a much higher risk that the joint will break as you flex the wire to install the washer or lug in the terminal block.

John C.

Yes, as mentioned above, using PC board material as junctions comes in very handy when dealing with delicate magnet wire, or even when joining 2 wires together. I etch my own long PC boards and then cut them to the lengths I need, but cutting slots in the copper works just as well.   Here is an example of this type of installation.

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[ednadolski]

Soldering them to brass washers should work fine.

Brass may not be the best choice, since it becomes nonconductive as it oxidizes.   Phosphor bronze or similar may work out better for you.

Ed

[sp org div]

While I mull over the options for terminating, I also need to figure out a better way to remove the varnish from the leads.
Scraping, sanding, heating with an iron, torching, and acetone are some options I have researched.
Im not really sure if this coating is an enamel, laquer, varnish, epoxy, resin...
Have any of you tried the method of laying the lead on acetylsalicylic acid (asprin) and heating the end with the iron to remove (no puffing allowed).

J

[peteski]

Magnet wires are enameled. The best and quickest way to strip the enamel (and tin the wire at the same time) is to first dip the end of the wire in paste flux (I use electronic paste flux from Radio Shack) then dip the wire into a ball of molten solder on the tip of a soldering iron. That burns off the enamel and tins the bare copper.   Takes less than a second. The trick is that the iron has to be really hot. I normally run my iron around 600-700 F, but for stripping enamel I have to crank it up to 800 F.  If its not hot enough, the enamel won't burn off.

Before I found this method (no, I didn't come up with it myself), I tried few chemical methods and they all failed miserable (plus they were messy).  I even tried a liquid specifically made for stripping enameled wire (from MG Chemicals) and it also didn't work for me.

[RBrodzinsky]

The best way for magnet wire is to get a blob of solder hanging from the tip of your soldering iron, and then push the end of the wire into the molten blob. Removes the insulation and tins the wire at the same time.

[jagged ben]

Something along the lines of this would also be an option:
https://www.phoenixcontact.com/online/portal/us?uri=pxc-oc-itemdetail:pid=1770539&library=usen&tab=1

(No affiliation, and there are probably many, many alternatives.)

RR-Cirkits has something somewhat similar on their fan out boards.  (No soldering!)  Even if you do solder something like the part above to a PC board, an advantage is not having to re-solder if/when you have to change out a signal.