Manufacturing stylus, how do they do it?

BillWojo

BillWojo

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Ok, I know the only substance that will grind and polish diamond is in fact diamond.
I'm also familiar with precision grinding of small hardened steel parts with radius and angles and how its done. and I have seen some really small intricate parts ground to within 0.0001 tolerance. But grinding and polishing something like a micro line stylus sort of boggles my mind.
I know only a small handful of companies in the world can do this level of work and all of the cartridge manufactures rely on them. Has an article ever been written describing the process? Is anyone familiar with the equipment used and who makes it? If I had to make an educated guess, the equipment is manufactured in Switzerland and Japan.
I'd love to learn more about the process but I suspect it's a highly guarded secret.

BillWojo
 
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It’s a fair amount of trade secret. But the Chinese Make conicals. Soon all of them, if not already.

CNC machining can be used to grind diamonds. My guess is that very precise CNC lapidary machines have been developed for stylus shaping and polishing.
 
BillWojo said:
Ok, I know the only substance that will grind and polish diamond is in fact diamond.
I'm also familiar with precision grinding of small hardened steel parts with radius and angles and how its done. and I have seen some really small intricate parts ground to within 0.0001 tolerance. But grinding and polishing something like a micro line stylus sort of boggles my mind.
I know only a small handful of companies in the world can do this level of work and all of the cartridge manufactures rely on them. Has an article ever been written describing the process? Is anyone familiar with the equipment used and who makes it? If I had to make an educated guess, the equipment is manufactured in Switzerland and Japan.
I'd love to learn more about the process but I suspect it's a highly guarded secret.

BillWojo
Click to expand...
here you go

https://www.ad-na.com/en/product/jewel/product/stylus.html
 
I've worked in manufacturing all my life and I can explain how just about anything is made, actually I've seen so much of it being in field service. Making stylus is micro machining at a whole different level though. This was established well before CNC controls were common, it started on all manual machines.
Just holding and positioning the diamond when companies like Denon claim they orient the diamond so the grain is correctly oriented just boggles my mind.

BillWojo
 
I've seen that before in searching @Grenadeslio, they tell you what they can do but not how they do it except that today they use a lot of laser micro machining. That wasn't available 50 years ago.

All this reminds me of a story when the two largest manufactures of high precision jig boring machines were having a friendly competition. American company Moore Tool Company and Swiss company SIP (Société Genevoise d'Instruments de Physique) were trying to establish themselves as the best and most precise tool builder in the world.
Moore had their toolmakers make a drill bit 0.003 inches in diameter and drill a hole in a piece of steel. Now 0.003 is about the diameter of a human hair so it was no easy task.
Moore shipped it off to SIP, sort of poking their middle finger at them. It was shipped back to Moore with a note and upon inspection they found an even smaller drill bit was used to drill a hole through the shank of the drill bit that Moore had used. Talk about one-upmanship!

BillWojo
 
BillWojo said:
I've worked in manufacturing all my life and I can explain how just about anything is made, actually I've seen so much of it being in field service. Making stylus is micro machining at a whole different level though. This was established well before CNC controls were common, it started on all manual machines.
Just holding and positioning the diamond when companies like Denon claim they orient the diamond so the grain is correctly oriented just boggles my mind.

BillWojo
Click to expand...

many moons ago I was a machinist working at times to tolerances of 50/millionths of an inch making jet engine parts etc, numerical tape control NTC was just coming online lol. This was a time when machinists weren't just button pushers.

if you're familiar with machining then you know about lapping, whether it be the ways in a surface grinder, lathe, mill, or a diamond it's all the same. crazy to think the ways on a surface grinder working to these tolerances were lapped by hand.
 
BillWojo said:
I've seen that before in searching @Grenadeslio, they tell you what they can do but not how they do it except that today they use a lot of laser micro machining. That wasn't available 50 years ago.

All this reminds me of a story when the two largest manufactures of high precision jig boring machines were having a friendly competition. American company Moore Tool Company and Swiss company SIP (Société Genevoise d'Instruments de Physique) were trying to establish themselves as the best and most precise tool builder in the world.
Moore had their toolmakers make a drill bit 0.003 inches in diameter and drill a hole in a piece of steel. Now 0.003 is about the diameter of a human hair so it was no easy task.
Moore shipped it off to SIP, sort of poking their middle finger at them. It was shipped back to Moore with a note and upon inspection they found an even smaller drill bit was used to drill a hole through the shank of the drill bit that Moore had used. Talk about one-upmanship!

BillWojo
Click to expand...

unless you're blonde, my individual hair are 1 1/2 thou

heard that tale too, only I heard it as the Japanese drilling the hole in the bit. but heres the thing, unless they supplied the smaller bit as proof they most likely used EDM.

and if you look at the link I provided they show at the bottom how it's done. they make a jig to hold the diamond just like any machinist, use saws for rough cutting, grind, then hand lap the final product.

not to scare you off flying, but the profile of turbine fins in jet engines are hand lapped and checked by eye against guillotine gauges one at a time lol.
 
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I worked as a toolmaker until I started with Bridgeport Machine Tools as a factory service rep. I'm quite familiar with grinding and lapping processes. Very precise shapes are often form ground using a specially shaped grinding wheel.
Now to get the grinding wheel with the correct form is where the real mystery starts. Your typical radius and angle dresser that will work down to 0.0001 if your really skilled is much to coarse.
In the case of a grinding wheel for diamond, the profile would be applied to a cast iron wheel and charged with fine diamond grit.
Maybe a pantograpth type attachment on a super precision lathe with a reduction of 100:1 could be used to machine the cast iron lap? But transferring wheels from the lathe to the lapping machine introduces another whole set of problems such as runout.

By the way, the hole that SIP produced was done with a drill bit, it was left in the shank when shipped back to Moore.

BillWojo
 
BillWojo said:
I worked as a toolmaker until I started with Bridgeport Machine Tools as a factory service rep. I'm quite familiar with grinding and lapping processes. Very precise shapes are often form ground using a specially shaped grinding wheel.
Now to get the grinding wheel with the correct form is where the real mystery starts. Your typical radius and angle dresser that will work down to 0.0001 if your really skilled is much to coarse.
In the case of a grinding wheel for diamond, the profile would be applied to a cast iron wheel and charged with fine diamond grit.
Maybe a pantograpth type attachment on a super precision lathe with a reduction of 100:1 could be used to machine the cast iron lap? But transferring wheels from the lathe to the lapping machine introduces another whole set of problems such as runout.

By the way, the hole that SIP produced was done with a drill bit, it was left in the shank when shipped back to Moore.

BillWojo
Click to expand...

Did you see the bit personally, or just hear the tale? As I said, I heard it different from more than one source. The bit was shipped back with a note stating to look at it under a scope, when they did it had a hole through it lengthwise, supposedly from a drill. So I'm more apt to believe they used EDM, or it's just that, a tale.

as for the grinding wheel having the profile, sure, they used this to grind the Christmas trees on the blades, roughed the profiles on a hydrotil lathe, but the final profiles were all done by hand on special belt sanders, checked with guillotine gauges by eye.

And the ways on our surface grinders, lathes, mills, etc were scraped and lapped by hand on site, this process could easily be used on a smaller scale for diamond stylus I would think. And that's pretty much what the link and article I posted reveal, at least thats what I got out if it.

and as they aren't selling a million a day, and labor is cheap
 
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I'm pretty familiar with production of airfoils. Been in quite a few shops that made them.
As far as the drilled shank goes, I have to admit that I didn't see it. Depending on what year it was it could have been EDM drilled. Even that would have been a feat to make the electrode. I could however see a company doing it although a close inspection of the hole would give the tell tale signs of the method used. When I toured the Moore facility back in the eighty's I didn't want to ask the host about it, figured it would be rude. The temperature controlled room in the basement is where the really precise work was done. Fascinating to say the least. They were very close to the Bridgeport plant.
When I was up in Connecticut last year doing a job in the city of Bridgeport I drove by the old Bridgeport facility, 500 Lindley Street, just a 7 acre gravel field. A real shame and it made me sad, I spent a lot of time in that factory.

BillWojo
 
BillWojo said:
I'm pretty familiar with production of airfoils. Been in quite a few shops that made them.
As far as the drilled shank goes, I have to admit that I didn't see it. Depending on what year it was it could have been EDM drilled. Even that would have been a feat to make the electrode. I could however see a company doing it although a close inspection of the hole would give the tell tale signs of the method used. When I toured the Moore facility back in the eighty's I didn't want to ask the host about it, figured it would be rude. The temperature controlled room in the basement is where the really precise work was done. Fascinating to say the least. They were very close to the Bridgeport plant.
When I was up in Connecticut last year doing a job in the city of Bridgeport I drove by the old Bridgeport facility, 500 Lindley Street, just a 7 acre gravel field. A real shame and it made me sad, I spent a lot of time in that factory.

BillWojo
Click to expand...

we used wire feed for really small EDM holes 45yrs ago, anything that will conduct electricity will work.
 
Yea, after I posted that I was thinking I have seen copper used for electrodes. Copper magnet wire carefully straightened and cleaned of the enamel would work just fine if you can control the current.
EDM, both wire and ram was a real game changer in the tool and die shops as well as the mold industry.
A shop HAD to buy into the technology or they would be gone almost overnight. Crazy times back than. Technology was changing so fast with the power supply's and burn rates that bigger shops were updating every two years or so and the older machines were being snapped up by the smaller shops. It was a real rat race.

BillWojo
 
BillWojo said:
Yea, after I posted that I was thinking I have seen copper used for electrodes. Copper magnet wire carefully straightened and cleaned of the enamel would work just fine if you can control the current.
EDM, both wire and ram was a real game changer in the tool and die shops as well as the mold industry.
A shop HAD to buy into the technology or they would be gone almost overnight. Crazy times back than. Technology was changing so fast with the power supply's and burn rates that bigger shops were updating every two years or so and the older machines were being snapped up by the smaller shops. It was a real rat race.

BillWojo
Click to expand...

my old brain just remembered the whole story, it goes exactly as you told it, but you only had half the story.

The company that had drilled the hole through the other drill then sent that around showing what it could do.

A Japanese firm sent the drills back with the note to look at them under a scope, they had drilled a hole lengthwise through the smaller drill lol.
 
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