Airline cutting lathe with Sapphire stylus?

[Oscar the cat]

Hi, I'm new here, I'm from Barcelona (Spain) I just started cutting laquers with steel needles, in my Airline home cutting lathe, but I would like to know if I can use a sapphire needle. I saw some Audiopoint sapphire needles on ebay but I don't know if it would fit my cutting head. (It's almost the same as a Recordio cutter, wilcox&gay etc...).

The seller says that: The sapphire tip of the needle extends about 1/8" from the shank and the total length of the needle is about 3/4". The shank is 1/16" which seems to be the standard diameter for a cutting stylus.

Anyone knows if this is good to use in a Recordio cutter, Airline, Wilcox&Gay etc...

Thanks!

[Angus McCarthy]

I believe the average "home recorder" used short-shank styli - both steel and sapphire tipped. A long-shank stylus could work, but it means the head would be trying to work against much more torque. Imagine holding a pencil from the eraser end and trying to write with it.

[Oscar the cat]

I made one recording with a steel needle:

https://soundcloud.com/gang-wolf-lightnin/somebody-stole-my-jane

I used a 1942 Yellow Audiodisc. It's my first acetate home recording, so you can hear extra saturation, I would like to improve the sound, the first; put a sapphire needle, I heard it cuts clear.

2nd: use some heat maybe?

I saw some short shanks on ebay, and the grampian apollo sells, any recommendations?

Any ideas are welcome.

Thanks!

[Angus McCarthy]

It's not so much that a sapphire stylus is inherently sharper to begin with - it's that it lasts much longer than a steel stylus, and won't rust.

Whatever you find, keep in mind the difference between older Standard-width styli meant for playing back with a 78 (3-mil) pickup, and microgroove styli meant for playback with more modern pickups (0.7-mil). It's safe to assume most old stock cutting styli will be Standard width, unless they're marked as microgroove. You'll find you get more noise trying to play a Standard groove with a modern stylus, even though it may be a relatively clean cut, since the smaller playback needle will ride in the bottom of the groove.

[Oscar the cat]

I've got a 2.5mm needle to reproduce old 78's and it sounds decent. I use the same needle to reproduce my acetate home records.

Do you mean that the sound quality is the same using sapphire or steel? and the only difference is that sapphire last longer?

I heard sapphire cuts with better quality and less background noise...

So if I cut with a new grampian short shank ruby stylus, I have to reproduce it with the 0,7 mil needle?

I will try to find an old stock sapphire then...

Thanks!

[Steve E.]

No matter what, you will get better results using a fresh Apollo lacquer (dub plate or reference lite). This is the voice of experience talking. A 70 year old disc will be rock hard.

[Techie]

I would be cautious about using a cutting stylus longer than what is intended for that machine. That type of cutter is limited in it's range of adjustment of angle and depth and you might accidentally gauge thru the lacquer when you lower the arm. It might be ok, but I'd procede with caution.
Also, if the cutter is of the crystal type, heating the stylus could transfer heat to the cutter head and ruin it. Not an issue if the cutter is magnetic, but a crystal is typical for that kind of recorder.

[Angus McCarthy]

No matter what, you will get better results using a fresh Apollo lacquer (dub plate or reference lite). This is the voice of experience talking. A 70 year old disc will be rock hard.

This is why the NOS lacquers I acquire are mostly fated to remain un-cut.

The problem with all the old steel styli is that 1) they've been sitting around for 70 years slowly oxidizing, and 2) they were disposable with a very short lifespan, heavily mass-produced and therefore not as precise a product as sapphire tips.

[Steve E.]

The one good thing about steel styli is that you can actually sharpen them yourself, on a sharpening stone. I do this. at this point I prefer using an old steel needle on my Recordio when I cut picnic plates.

[piaptk]

You can definitely use any short shank (or long shank that has been trimmed to size) on that. Steel needles were actually thicker than sapphires I think, because a steel needle won't fit in my presto head.

And I second what Steve said. Do yourself a favor and buy a couple new lacquers and a fresh stylus. I wasted months trying to get decent sound out of steel needles and 70 year old lacquers because I didn't know any better. As soon as I bought a decent stylus and a new lacquer, I was amazed at the sound I started getting from my little suitcase lathe. Then, once you have a benchmark you can move onto cutting stuff like picnic plates which are much cheaper..

[Oscar the cat]

The one good thing about steel styli is that you can actually sharpen them yourself, on a sharpening stone. I do this. at this point I prefer using an old steel needle on my Recordio when I cut picnic plates.

Great! and what about sapphire? cannot sharpen?

Is the quality of picnic plates similar to CD's?

It's better to use a steel needles than sapphire needles for those picnic plates?

Thanks

[Angus McCarthy]

You can re-grind sapphire styli - in fact it used to be a service provided by several equipment manufacturers.

Unfortunately, it takes somewhat precise equipment and knowledge of the stylus geometry. It's an actual jewel, and that takes a specific skill set to work with effectively. Unless I'm mistaken there isn't anybody at the moment re-sharpening sapphire tips, at least not publicly.

[Oscar the cat]

So people use sapphire/ruby till the needle is dull? and then buy a new one?

I tried to sharpen a steel needle and I couldn't cut... it's so hard to get the right angle, anyone knows a good technique? thanks!

[markrob]

Hi,

I've played with grinding and lapping high speed steel cutting stylii with a home brew template faceter. I was using 1/16" diameter drill blanks, which are easy to purchase. The template faceter is a cheap and simple way to grind/lap the angles you need in a repeatable way. The actual numeric value of the angle is no too critical. You just want to have good repeatablity and nice flat surfaces that can be lapped to a mirror finish. Here is a link to a YouTube video of one in action:

http://www.youtube.com/watch?v=1_fmqWBBUdk

And A link to my web page with some shots of my version:

http://home.comcast.net/~markrob1066/site/?/page/Cutting_Stylii/&PHPSESSID=868d88cf19204b7b187ef7adcc677919

The expensive part is the diamond lap wheel.

Hope this helps.

Mark