Homemade tungsten needles

Q&A about Talking Machines from the pre-electronic era (approx. 1885-1928).



Topic author
frenchmarky
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Joined: Mon Aug 31, 2009 3:15 pm

Homemade tungsten needles

by frenchmarky » Fri Oct 02, 2009 11:11 pm

I am retiring in less than a month so in looking at my current hobbies, I've decided to try goofing around with making my own tungsten needles. Partly whim; partly because Tungstones are so expensive and hard to find nowadays; and finally because I now have a Victrola 10-50 which has the up-to-12-records changer. Can't use the changer with steel needles unless I want to disable the changer and change the needle with each record -- NO FUN!!

Soooo I managed to find some .006" pure tungsten wire from smallparts.com, and I'm using VERY crude methods to make the needles, but they work and sound great, and I certainly don't need to make them quickly, or very many of them, for my own use. I've been told that the best wire size would be more like .005 to .0055, but I couldn't locate any in stock as of yet. The same source said that Victor used .0055 - .006" wire, and that .006" would be nominally ok (I found on the net that the width of the top of the grooves of early 78s was about .006 - .0065" but it varied a little by company, year, etc.) I've compared the wire size to that in my NOS "Tonofone" tungsten needles, by fitting/swapping both wires between two straightedges. Results -- this wire is actually a little skinnier, so I feel quite safe in using it on my already-beat-up records. My guess is the the wire is actually smaller than .006" due to the +-.001 rated tolerance, but I've got a micrometer on order to check it for certain.

Anyway, all I'm doing so far is using very small screws and nail shafts as the shank, using a Dremel with cutoff wheel to make a slot, then carefully peening the shank's slot to hold the needle. Sometimes I can get a good final grip by just squishing it with pliers or a vise instead. Then I *carefully* cleanup and shape the shank tip around the wire to be more or less pointed, with the wire at the center of course. Then there is clipping the wire to the appropriate length (very critical to not be too long or will inevitably become bent!) Then I tweak the end of the shank as needed to end up with a straight tip. The resulting needles are ugly as heck and no two look alike, but oh well they work great. I'm imitating Victor's method of the wire being mounted into a slot, except of course theirs was a lot more precise and complex, with the tip being pressed into a die to squeeze the slot closed.
Oh, and their needles weren't hideous! Finally I am prepping each needle by playing once on a crummy acoustic record (has the full abrasives in it, to sharpen & shape the tip.) Victor pre-prepped their needle tips but doing this pre-use prepping is still recommended.

I'm still experimenting, so I'll start prepping the tip before placing the wire. Next I'm going to try using very fine brass rods or tubing (like hobby stores sell for r/c cars and such) for the shank, since it's softer and is what the manufacturers used. Also made a few where I've soldered the shank around the wire with regular electronics solder, simply to make sure the tip is totally secure at the exact point where it exits the shank.

I don't need to get into mass production or create beautiful needles here, just going to be cranking out one or two once in a while as needed for my 10-50 use. The main impetus for this is my 10-50 changer -- not whether tungsten needles may or may not wear records more than steel needles. Using the changer is half the fun of this machine : ) 25 feet of the wire was only 12 bucks so this is practically free so far too.

Comments/criticisms/additional info appreciated!
... Mark


slippery
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Re: Homemade tungsten needles

by slippery » Thu Oct 08, 2009 12:20 am

I've found a quick(ish) way to make them is to glue the wire inside a suitably shortened hypodermic needle,using the center part of the hard plastic shank to fit the needleholder of the soundbox.They sound similar to a soft tone,but you have to keep an eye on the wear as the hypo will play even when the tungsten has worn down!


Topic author
frenchmarky
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Posts: 17
Joined: Mon Aug 31, 2009 3:15 pm

Re: Homemade tungsten needles

by frenchmarky » Tue Oct 13, 2009 12:31 pm

I'm going to experiment with brass tubing also, I figured that the fact that it's hollow like your hypo needles would lighten the volume. What size wire are you using?
With .006, the only problem is that I have to make them shorter than they could be with .007 (i.e. the Tonofones). Otherwise they are be more likely to get bent just from the weight of the reproducer plus the groove's sideways drag on it while playing, and from hitting gouges in records. Maybe that's why Tonofone went with .007. It was suggested that .005 would be even better for the grooves, but that would exascerbate the length issue. Orthophonic soundboxes aren't exactly light! Then again, shorter length isn't a big deal when I can make as many needles as I want for practically nothing.
I like your superglue suggestion, I'll start using that at the base of the wire after mounting it in the shank, just to make sure it can't start wiggling loose and possibly cause buzzing. That has happened on some of my needles and I had to re-squish the tip. I've tried adding solder at the tip but it just doesn't want to stick to the base of the needle.
My main issue I'm trying to get rid of is making the tip "record safe" when it wears down to the nib, so when the wire wears out, the shank can't start scraping the record. (Same issue as yours wearing down into the hypo tip itself.) Till I can come up with points as nice and perfectly pointed like Tonofones or Tungstones anyway. Perhaps I could use some thick paint or glue etc. at the base of the wire, so when the tip is obviously *sounding* worn down to the nub, it will only be rubbing the record with the soft paint or other substance instead of sharp metal - till I can go yank it off for a replacement.


Topic author
frenchmarky
Junior Member
Posts: 17
Joined: Mon Aug 31, 2009 3:15 pm

Re: Homemade tungsten needles

by frenchmarky » Fri Oct 16, 2009 6:28 pm

I've softened my process a bit : )
Now I'm cutting a slot in the shaft, then just pressing the wire in the slot using either a vise or visegrips, a bit more precise and gentler than hammering it, hah. Then I put a micro-drop of superglue on the end at the base of the wire, and trim/point the end with the dremel. Then a final cut of the wire, and of the shaft to the standard needle length. If the wire ends up not coming out perfectly straight, it 's easy to tweak the tip with these basic tools so the wire exits straight.
I have horrible nearsightedness -- which is actually helpful for the dremel trimming. I take my glasses off and put on safety glasses, that way my eyes are like microscopes and I can do pretty precise trimming of the tips. Have to go slow and have a steady hand to avoid slicing off the wire. I'd prefer to point the tip *before* crimping in the wire, but my crimping operation is just too crude right now to center the wire at an exact point.

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