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Steve E.
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Request: Specs, ANY pre-1948 cutting stylus ("Standard")

Post: # 27981Unread post Steve E.
Sat Nov 30, 2013 11:41 am

It has become clear to me, based a recent project cutting live to 78 rpm with my Presto 6N, that it would be REALLY good to have a batch of old fashioned standard groove cutting styli made up. This has been an ongoing debate around here, but I'm convinced that if you want to cut 3 mil wide grooves at 78 rpm, you need to cut wide WITHOUT cutting deep. It's just too much friction and too much risk of chipping the tip. I'm no longer suggesting that labels putting out 78s should do it with something other than microgroove. This is simply for certain on-the-fly live recording situations where a wide groove might be desirable because of the expected playback devices.

A vendor has expressed a willingness to try making some of these for me, but they need info on all the angles of such a stylus, including the bevels. Someone sent me an old stylus but it proved hard to get the needed info off of it (I may try again in a pinch). If anyone has such info in printed form, please do post it here. I fear it is lost data.

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boogievan
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Re: Request: Specs, ANY pre-1948 cutting stylus ("Standard")

Post: # 27996Unread post boogievan
Mon Dec 02, 2013 3:06 am

You're so fast! I believe 0,003 inches (aka, 3,0 mils) is the suggested tip radius for playback of a 77,92 (@50Hz) / 78,26 (@60Hz) rpm record. You might therefore want to make a truly coarse groove cut, since most "78" record players are set up for it being relatively wide, unless you can label it clearly as a hybrid, microgroove cut for 78 rpm angular V... Todd66 might be able to fashion coarse cutting jewels out of diamond. Might last longer if they have more bulk? (: If he can add the burnishing facets, you can have lower lacquer noise, but this is at the expense of slightly diminished treble... I haven't heard any smooth vinyl "78's," however... only slates, which I think involve gold-sputtering hot wax cuts for the Brugnatelli cell, rather than sugar-Silver shooting them.)

For microgroove cuts, the suggested pickup tip radius is now 0,000,7 inches, however, one cuts with much greater base width than 1,4 mils, normally. 2 mils is a good width for micro... especially if depth automation is included... But for "78s," you normally cut laterally and pick a more comfy width to seat and "channel" the pickup stylus.

I hear that Mr. H. cuts 10 mil wide grooves after repairing Westrex cutters as a test drive. If he's using a microgroove stylus, then that would make the depth equal 5 mils, leaving only ~2 mils of lacquer atop the Apollo's alu substrate - brinksmanship someone such as he can pull off safely. But, if he actually uses a coarse groove stylus, then it has an included angle of 110 degrees, which is a bit wider than the 90-degree included angle of the microgroove jewel, and this leaves more of a pearl-pulling buffer between the tip of the cutting stylus and the alu substrate. Surf's up!

If you ladel your own hot wax spinsters, you can make it thick enough that you don't care how wide you grow... ...plus, you get to spread and debubble the "soap" with a torch!

(Lead litharge, Montan wax, Stearin, Paraffin, Ozokerite, Barium sulfate, and soda ash...)

Width sympathy,
Boogsy

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opcode66
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Re: Request: Specs, ANY pre-1948 cutting stylus ("Standard")

Post: # 27997Unread post opcode66
Mon Dec 02, 2013 3:34 am

We are waiting for prototypes to see if we can kill the static issue for cutting lacquer. Then, we can possibly look into making a non-microgroove tip. But, burnishing facets are probably never gonna happen. It would add to the cost. Already, they are expensive...
Cutting, Inventing & Innovating
Groove Graphics, VMS Halfnuts, MIDI Automation, Professional Stereo Feedback Cutterheads, and Pesto 1-D Cutterhead Clones
Cutterhead Repair: Recoiling, Cleaning, Cloning of Screws, Dampers & More
http://mantra.audio

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Steve E.
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Re: Request: Specs, ANY pre-1948 cutting stylus ("Standard")

Post: # 28309Unread post Steve E.
Thu Jan 02, 2014 7:50 pm

Related post:

https://www.lathetrolls.com/viewtopic.php?f=9&t=4631

Still love to get as much data as possible on ALL angles and facets of old pre-heating-era cutting styli. Microgroove, too, in fact, since they seem to have changed.

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dubcutter89
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Re: Request: Specs, ANY pre-1948 cutting stylus ("Standard")

Post: # 28321Unread post dubcutter89
Fri Jan 03, 2014 7:08 am

maybe try to look for old patents
just enter "capps stylus patent" in google

might be interesting for some others as well...

Lukas
Wanted: ANYTHING ORTOFON related to cutting...thx

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Steve E.
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Re: Request: Specs, ANY pre-1948 cutting stylus ("Standard")

Post: # 28373Unread post Steve E.
Mon Jan 06, 2014 9:03 am

Steve E. wrote:- - - - just sent me things from the old Read recording book, and it seems to contend that the old "Standard" Capps styli were also 87 to 90 degrees!! They just had a larger radius on the tip at bottom!! So I may have been barking up the wrong tree all this time??? Where were we getting 100 to 110 degrees?

I wonder if this old thread of mine, about a steel cutting needle, was the source of any of the confusion:

https://www.lathetrolls.com/viewtopic.php?f=8&t=3256&p=19585

angle-compare.jpg

side-angle.jpg
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Steve E.
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Re: Request: Specs, ANY pre-1948 cutting stylus ("Standard")

Post: # 28404Unread post Steve E.
Mon Jan 06, 2014 9:48 pm

Check out this brochure by the Diacoustic company. They had some sort of association with Capps.

This is early microgroove era. It tells us a lot.

Most cutting styli, either microgroove or standard, were in the 87 to 90 degree range. One stylus offered here is 95 degrees, probably for very wide groove records (80 to 88 LPI, according to some other literature).

Writings by Isabel Capps (1946) and Oliver Read (1952) mention 70 degree styli, and, in the former case, an experimental 100 degree stylus. It appears 70 degree styli were not the most typical in the transcription era, but not uncommon.

The takeaway I'm getting from this stuff: The difference between "standard" groove" and microgroove is not so much in the angle of the walls. It's the radius of the tip. Microgrooves are sharper at the bottom.

I know this might be a big "duhhhh" to a lot of you....but to perpetual newbie me, it's a revelation.

I'm finally understanding why 78s play badly with a microgroove stylus: The sharp playback needle sits in the rounded base of the groove, exactly where it should not be. There's little audio information there.

This also explains Kris D's claim, in another thread, that he has released records that would play OK with either a 78 or microgroove stylus. The grooves have a sharp bottom, yet they are deep enough that a 78 playback stylus will ride on them.
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Re: Request: Specs, ANY pre-1948 cutting stylus ("Standard")

Post: # 28406Unread post Steve E.
Mon Jan 06, 2014 11:01 pm

1946 article by Isabel Capps. The lathe troll who sent it my way expressed concern about copyright infringement. I am going to guess that at this point this is a public domain article, but of course I will take it down if I am alerted to infringement or even of muscling in on somebody's racket. Parties of interest, please let me know.
isabel-capps-1.jpg
isabel-capps-2.jpg
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isabel-capps-4.jpg
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Steve E.
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Re: Request: Specs, ANY pre-1948 cutting stylus ("Standard")

Post: # 28407Unread post Steve E.
Mon Jan 06, 2014 11:13 pm

I should say....

I think these scans may be reprinted in a book, "Disk Recording 1930-1960 Equipment, Techniques, Recollections by Robert K. Morrison." This book has been advertised on this site by gearheadgirl. Buy it!!!

https://www.lathetrolls.com/viewtopic.php?f=4&t=904

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Re: Request: Specs, ANY pre-1948 cutting stylus ("Standard")

Post: # 28668Unread post tragwag
Tue Jan 21, 2014 2:55 pm

that is an excellent book, and thanks for the info steve!
though it may seem a simple find, it's good to rule out angle as the most important difference between standard and microgroove styli. now you can go forward knowing that the width is the pertinent factor here.
making lathe cuts on a Presto 6N, HIFI stereo cuts on vinylrecorder
at Audio Geography Studios, Providence, RI USA
http://www.audiogeography.com

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