Recordio Record Lathe + Heating Stylus QUESTION!

[HardlyHumanFX]

Hey guys!

So I FINALLY have my Recordio 72A fully restored. Idler wheels rebuilt, all new tubes, and West Tech rebuilt crystal cutter head. (hear it on instagram at HardlyHumanFX)

I have played around a bit with trying to heat records but they always warp so I decided to heat my stylus instead. I first tried some nichrome wire wrapped around the stylus and attached it to some D batteries. The results were inconsistent but they were better than an unheated stylus/record.

I saw a PDF file in the thread about making your own heating stylus about using nichrome but I didn't see anything about insulating the needle. Are people just wrapping the needle? Isn't it also conductive? In my primitive battery tests, I made a sleeve out of epoxy putty to encase my wires and insulate them from the needle.

Thoughts? I know a recordio is 1930s consumer technology but it's what I have to play with. I LOVE 78s and I LOVE mono.


Jason Anderson, 29
Orange, California

[markrob]

Hi,

I had good luck just wrapping a few turns of nichrome wire on the mental shank. I used Duco cement (made out of nitrocellulose, just like a lacquer blank) to bond the turns. If the Duco starts to smoke, the heating level is a bit too high. Give it a try and see if it works for you.

Using D Batteries (or any power supply) without any means to adjust and monitor the current is a not good idea. You want some simple way to adjust. 3 or 4 D batteries in series with a 100 ohm 5-10 watt rheostat should do the trick. I would also add in a 3 ohm 10 watt resistor in series with the rheostat to limit the current to a safe level is a good idea. Add a DC current meter with a full scale range of 2 amps will allow you to accurately set the coil current. Typically, you will run in the 500 ma. range. But that is dependent on the wire and the platter speed. You may need to play with these values to get the best range.

Hope that helps.

Mark

[HardlyHumanFX]

Hi,

I had good luck just wrapping a few turns of nichrome wire on the mental shank. I used Duco cement (made out of nitrocellulose, just like a lacquer blank) to bond the turns. If the Duco starts to smoke, the heating level is a bit too high. Give it a try and see if it works for you.

Using D Batteries (or any power supply) without any means to adjust and monitor the current is a not good idea. You want some simple way to adjust. 3 or 4 D batteries in series with a 100 ohm 5-10 watt rheostat should do the trick. I would also add in a 3 ohm 10 watt resistor in series with the rheostat to limit the current to a safe level is a good idea. Add a DC current meter with a full scale range of 2 amps will allow you to accurately set the coil current. Typically, you will run in the 500 ma. range. But that is dependent on the wire and the platter speed. You may need to play with these values to get the best range.

Hope that helps.

Mark

Hi Mark!

Very helpful! I have a power supply and ammeter set up to be delivered soon. I'm 3D printing a holder that I can mount on the cutter arm to keep everything clean looking. Also want to add a vacuum to collect shavings!

Thanks for the tips! Oh! The turtle wax thing is really perplexing me. Is it the actual buff on wax or another product?? (I'm using 3mm thick pvc/vinyl blanks)

Thanks!

Jason

[grooveguy]

Hi, Jason, a couple of questions. 1) are you cutting with a traditional stylus, or are you embossing with a spherical tip? 2) what speed(s) are you recording at?

Typically with a Recordio or other vintage-consumer-targeted machine, a hot stylus doesn't work all that well. I am assuming that your cutterhead is the usual Astatic piezo (crystal) head, which is somewhat sensitive to temperature. That's one caution. Then there's your stylus. If it's steel or other all-metal one, it's probably going to conduct heat away as fast as you can apply it. The heated stylus technique has always been reserved for sapphire/ruby/diamond tips, which will not short-out the turns of the heating coil, and which concentrate the heat in the jewel where it does some good. Plus, you HAVE to have some sort of suction mechanism to pick up the chip/swarf before it melts or bursts into flame!

I use a special wire to heat my cutters, and I can't really tell you what it is. I obtained it close to 60 years ago when I worked a summer for Jennings Radio in San Jose. They did a lot of high-power, high-voltage work and had scads of glass-tube power resistors. I accidentally broke one and was allowed to keep it. It was wound with "resistance wire" on a ceramic form, and the wire was covered with a white powder. I still use pieces of that wire to re-wire the sapphire styli I use on my Rek-O-Kut lathe with a Fairchild head. In operation it looks like this:

CU.jpg

If you get into cutting 33-1/3 speed microgroove-type grooves with a small radius jewel tip, you can probably do the same thing... even with the crystal head on the Recordio. But for 78s, or for embossing, I don't think it's going to do you any good.

I'm not far from you in Orange County, and if I can be of help, let me know.

[HardlyHumanFX]

Hi, Jason, a couple of questions. 1) are you cutting with a traditional stylus, or are you embossing with a spherical tip? 2) what speed(s) are you recording at?

Typically with a Recordio or other vintage-consumer-targeted machine, a hot stylus doesn't work all that well. I am assuming that your cutterhead is the usual Astatic piezo (crystal) head, which is somewhat sensitive to temperature. That's one caution. Then there's your stylus. If it's steel or other all-metal one, it's probably going to conduct heat away as fast as you can apply it. The heated stylus technique has always been reserved for sapphire/ruby/diamond tips, which will not short-out the turns of the heating coil, and which concentrate the heat in the jewel where it does some good. Plus, you HAVE to have some sort of suction mechanism to pick up the chip/swarf before it melts or bursts into flame!

I use a special wire to heat my cutters, and I can't really tell you what it is. I obtained it close to 60 years ago when I worked a summer for Jennings Radio in San Jose. They did a lot of high-power, high-voltage work and had scads of glass-tube power resistors. I accidentally broke one and was allowed to keep it. It was wound with "resistance wire" on a ceramic form, and the wire was covered with a white powder. I still use pieces of that wire to re-wire the sapphire styli I use on my Rek-O-Kut lathe with a Fairchild head. In operation it looks like this:

CU.jpg

If you get into cutting 33-1/3 speed microgroove-type grooves with a small radius jewel tip, you can probably do the same thing... even with the crystal head on the Recordio. But for 78s, or for embossing, I don't think it's going to do you any good.

I'm not far from you in Orange County, and if I can be of help, let me know.

Hi!

I live in the city of Orange. Good to meet you! The recordio uses a crystal astatic cutting cartridge. I'm using metal spade shaped cutter stylus. I've only tried to cut at 78RPM. I've tried to heat the disc but can't get away from warping. I do want to purchase a sapphire cutting needle to try. I know that any audible hiss I hear the cutter head make while its cutting the record will show up on the recording. I'm not sure what to do if I can't retro-fit a heater wire on my needle. I have tried to adjust the cut depth on the cutter head but when the hiss goes away, so does the loudness of my recording.

I've tried rubbing my pvc discs with lighter fluid to lubricate/soften them. I've tried turtle wax as suggested. I wasn't really getting anywhere.

Jason

[grooveguy]

Hi, Jason,

Yeah, I'm in Brea, just a hop-skip-jump away. If you're cutting at 78 into a bona fide lacquer recording blank, and the stylus is fairly new, you should have virtually no noise.

Back when I was a kid doing much the same thing with a General Industries recording deck, I'd get noiseless 78 recordings using a fresh steel stylus cutting an Audiodisc yellow-label blank. But steel gets dull very quickly. A sapphire lasts a long time. When you're cutting, oil and similar stuff applied to the surface really does nothing... that's more for embossing.

I actually have a NOS (never opened) Astatic brand sapphire stylus for wide-groove recording.

DSCN5302.JPG

DSCN5303.JPG

I have no real use for this, but was going to put it on eBay just to see what it would fetch. It's a 'long shank' stylus for Presto heads, but you just cut it down from 3/4" to 5/8" and it fits most others. Not even sure where to start with an asking price, probably $20. There are sapphire styli from the former Soviet Union on eBay for less than that. I'd pick one up, get some good blanks, and see what you can do.

[HardlyHumanFX]

Hi, Jason,

Yeah, I'm in Brea, just a hop-skip-jump away. If you're cutting at 78 into a bona fide lacquer recording blank, and the stylus is fairly new, you should have virtually no noise.

Back when I was a kid doing much the same thing with a General Industries recording deck, I'd get noiseless 78 recordings using a fresh steel stylus cutting an Audiodisc yellow-label blank. But steel gets dull very quickly. A sapphire lasts a long time. When you're cutting, oil and similar stuff applied to the surface really does nothing... that's more for embossing.

I actually have a NOS (never opened) Astatic brand sapphire stylus for wide-groove recording.

DSCN5302.JPG

DSCN5303.JPG

I have no real use for this, but was going to put it on eBay just to see what it would fetch. It's a 'long shank' stylus for Presto heads, but you just cut it down from 3/4" to 5/8" and it fits most others. Not even sure where to start with an asking price, probably $20. There are sapphire styli from the former Soviet Union on eBay for less than that. I'd pick one up, get some good blanks, and see what you can do.

Sent you a PM :] thanks!