The dark art of diamond sharpening

[alexsation]

I'll also add: if you're making a stylus from scratch, you should have another machine with a cast-iron diamond blade. The sword shape should only be shaped on a cast-iron diamond blade; if you use a metal-ceramic diamond blade, the entire surface will be covered in deep pits.

P.S.
Perhaps my translator is translating the text incorrectly. If something is not clear, please write to me and I will try to respond in a timely manner.

[classd2008]

I'll also add: if you're making a stylus from scratch, you should have another machine with a cast-iron diamond blade. The sword shape should only be shaped on a cast-iron diamond blade; if you use a metal-ceramic diamond blade, the entire surface will be covered in deep pits.

P.S.
Perhaps my translator is translating the text incorrectly. If something is not clear, please write to me and I will try to respond in a timely manner.

Thank you for replying; in fact, I'm on a path to do something good that doesn't cost a fortune. Regarding the cast iron disc, I didn't see that machine on your Instagram channel, or maybe I saw it and missed it.

I noticed you've been making your own cutting needles. Have you achieved a satisfactory result yet?

[alexsation]

Thanks for the question!
I've been through this difficult process for a long time. I spent a whole year experimenting. I've been producing perfect diamond needles for a long time now, and I have no problems with it. Many people ask me to sell and repair needles, but despite having a well-established process, I have no desire to sell needles. I supply needles to everyone who does lathe cutting in Russia. I have a lot of Instagram posts where I show my results and processes. I have a powerful machine with a cast-iron disk; it's a large and heavy machine weighing 200 kilograms.
If you're interested, here's my Instagram: @vinyliumrecords

[classd2008]

Thanks for the question!
I've been through this difficult process for a long time. I spent a whole year experimenting. I've been producing perfect diamond needles for a long time now, and I have no problems with it. Many people ask me to sell and repair needles, but despite having a well-established process, I have no desire to sell needles. I supply needles to everyone who does lathe cutting in Russia. I have a lot of Instagram posts where I show my results and processes. I have a powerful machine with a cast-iron disk; it's a large and heavy machine weighing 200 kilograms.
If you're interested, here's my Instagram: @vinyliumrecords

Yes, I've been following you on Instagram for a while and I've noticed that you're someone who doesn't hide anything and is always posting about your machines and how they work. In this field, I've noticed that not everyone wants to help, but rather to profit. That said, even here on the forum, many people ask for help and when things start working, they don't share anything anymore and use it commercially. I don't think it's wrong for some to do that, but with you it's always different, and you share everything on Instagram. I'm developing my vinyl cutting machine based on yours, not the most recent lathe, but the one from some time ago. I would really like to know the exact measurements because I'm designing one very similar to yours in SolidWorks, but since I don't have the measurements, I'm trying to figure it out from references. Thank you very much for sharing so much on Instagram.

[alexsation]

I'm glad people follow my work. Since this forum thread is about diamond machining and not lathes, I'll keep it short. I spent several years developing and refining the lathe you're talking about. A huge amount of money was spent making it profitable. I cannot give you the work of several years of my life.
If you own a Solid Works, it shouldn't be difficult for you to make your own.
If you have any questions about grinding diamond needles, I'd be happy to share my knowledge.

[Estrada]

I'm glad people follow my work. Since this forum thread is about diamond machining and not lathes, I'll keep it short. I spent several years developing and refining the lathe you're talking about. A huge amount of money was spent making it profitable. I cannot give you the work of several years of my life.
If you own a Solid Works, it shouldn't be difficult for you to make your own.
If you have any questions about grinding diamond needles, I'd be happy to share my knowledge.

Hi, thanks for your input into this thread. I've also been following your work on instagram, in fact my current methods are based on your earlier work with resin bonded discs. I did want to ask you one question about your stylus making. I none of your videos you are installing the diamonds into the aluminium shanks using what looks like a 2 part epoxy which is thin enough to be injected with a medical syringe. Unless it is a trade secret, are you able to tell me what type of adhesive is this and where it is available from?

[alexsation]

Hi!!
I have no secrets, and I'd be happy to help. Gluing the diamond into the shank is the easiest and fastest part of the process. I use a one-component epoxy adhesive called DKD. I don't think you'll find the same adhesive in your country, but I might be wrong. It's a liquid adhesive designed for gluing speaker and subwoofer voice coils. To dry the adhesive, bake it in the oven for 1 hour at 120 degrees Celsius. Once baked, the adhesive can never be dissolved by anything, and the diamond will never come off.

1) I insert the diamond into the aluminum shank. Next, I use a syringe with glue and a 0.1 mm needle. The needle is not a medical one, but a technical one with a blunt tip. The glue fills the voids around the diamond core, and that's it. After that, the stylus is placed in the oven.

2) The heating wire is glued with the same glue. First, the wire is wound, then the wound coil is coated with glue using the same syringe and placed in the oven for 1 hour.

3) Cleaning the diamond of glue and shank.

Previously, I mechanically removed the shank and removed the glue with a jeweler's knife. A lot of diamonds disappeared without a trace during the cleaning process. After some research, I found another method. If I place the diamond stylus in 15% hydrochloric acid, the aluminum shank dissolves within 1 hour. Then I remove the diamond from the hydrochloric acid and place it in 50-70% nitric acid. After a few hours, the glue softens, and after rinsing in pure alcohol, the glue can be removed by hand. I receive a perfectly clean stylus ready for repair. This is my personal method. It works like a Swiss watch.
The glue is baked in a miniature kitchen oven, which costs $20-30.
I'll try to make videos of some of the processes and post them here.

[alexsation]

This is a glue that will bond a stylus or any audio coil for ages. I think many people repair and create cutting heads. You won't find a better glue than this. Let me warn you right away: I'm not a supplier and I don't resell glue.

[classd2008]

Hi!!
I have no secrets, and I'd be happy to help. Gluing the diamond into the shank is the easiest and fastest part of the process. I use a one-component epoxy adhesive called DKD. I don't think you'll find the same adhesive in your country, but I might be wrong. It's a liquid adhesive designed for gluing speaker and subwoofer voice coils. To dry the adhesive, bake it in the oven for 1 hour at 120 degrees Celsius. Once baked, the adhesive can never be dissolved by anything, and the diamond will never come off.

1) I insert the diamond into the aluminum shank. Next, I use a syringe with glue and a 0.1 mm needle. The needle is not a medical one, but a technical one with a blunt tip. The glue fills the voids around the diamond core, and that's it. After that, the stylus is placed in the oven.

2) The heating wire is glued with the same glue. First, the wire is wound, then the wound coil is coated with glue using the same syringe and placed in the oven for 1 hour.

3) Cleaning the diamond of glue and shank.

Previously, I mechanically removed the shank and removed the glue with a jeweler's knife. A lot of diamonds disappeared without a trace during the cleaning process. After some research, I found another method. If I place the diamond stylus in 15% hydrochloric acid, the aluminum shank dissolves within 1 hour. Then I remove the diamond from the hydrochloric acid and place it in 50-70% nitric acid. After a few hours, the glue softens, and after rinsing in pure alcohol, the glue can be removed by hand. I receive a perfectly clean stylus ready for repair. This is my personal method. It works like a Swiss watch.
The glue is baked in a miniature kitchen oven, which costs $20-30.
I'll try to make videos of some of the processes and post them here.

Thank you for sharing.

[Fela Borbone]

I used this varnish, I think is similar, i baked it with a big infrared lamp

[Fela Borbone]

I can't find It anymore,
Thanks Alexsation for sharing...
Why stones are grinded whitout shank?

[alexsation]

1) The shank has a high-precision conical fit; after being installed in the cutting head seat, the shank changes shape slightly. If you resharpen the shank, you'll need to clamp the shank a second time in the collet, then reinsert the shank into the cutting head. The shank's shape and surface will be significantly deformed; you might not notice it, but it's true. If you follow this path, the cutting head seat will wear out much faster. This applies to the 320 shank.
2) The second reason is the shank design. If the diamond stylus has a fairly long diamond rod extension from the shank, you'll only be able to polish it once or twice. Once the diamond becomes shorter, the square skirt on the 320 shank will prevent you from sharpening the diamond; it will interfere and wear away along with the diamond.

The most accurate way is to remove the diamond from the shank, insert it into a collet, and sharpen it. When installing the diamond in a new shank, you can always control the diamond rod's protrusion from the shank to achieve the desired blade length.
The shank is a consumable item that only lasts one time, so don't skimp on it; repairing the cutting head will cost much more.

[classd2008]

Alexsation.
You use two machines to hone the needle, one to cut to the triangle point and the other for polishing. You use two disc weights; if you could say, what are they? Also, in one of your Instagram videos, you polish at 9,000 RPM, and how many RPM do you use to cut to the triangle point?

[alexsation]

I make the sword shape on a 300mm cast iron diamond disc. For polishing, I use a 100mm metal-ceramic diamond disc. There are standards for the rotation of diamond discs. A certain linear speed is required to remove the diamond mass. You can calculate it yourself. A 300mm diamond disc should rotate at 2800-3000 rpm; this is the standard specified in all textbooks. To achieve the same linear speed on a 100mm diamond disc, 9000 rpm is required. You can also use 6000 rpm to polish the blade, it will take more time to polish, but the result will still be good. The most important thing at this speed is perfect balance and a flawless surface; surface runout should not exceed 1-2 microns. Polishing the stylus will take a few seconds. At a lower speed, polishing one side can take anywhere from several minutes to tens of minutes.

[classd2008]

Alexsation.
Do you use Grit 10000 in all stages? Sorry for silly questions, but I'm really a layman on this subject.

[alexsation]

I wrote about the grain size of diamond discs in previous posts, please read them above.

[Estrada]

This is a glue that will bond a stylus or any audio coil for ages. I think many people repair and create cutting heads. You won't find a better glue than this. Let me warn you right away: I'm not a supplier and I don't resell glue.

Thanks Alexsation for your advice on this, and for your other input into the thread. It looks like the DKD adhesive is not available in many parts of the world but there may be some other options out there. Here are few I found after a quick google search.

https://thelordofbass.com/product/bpc6020-voice-coil-winding-laminating-cement/?srsltid=AfmBOoooRpOAcn254FNRDshZqQM9nu26CWXliBZLQs2t64818I6QXO8V

https://www.intertronics.co.uk/product/high-temperature-epoxy-adhesive-opti-tec-5054/

https://lautsprecher-technik.com/Speaker-Repair-Parts/Speaker-Repair-Parts-67/Glue-Adhesive/Voice-Coil-Winding-SV-Glue-Adhesive.html?language=en&srsltid=AfmBOooON6zTbvnF_knHKAHqUMfQlivPCiieUjBbKgh_dSfGML4JZRmA

There are likely others out there that I haven't stumbled across. I'm not sure if any of these have the low viscosity of the DKD so this is something I will need to look into more before ordering anything.

[Estrada]

I'm thinking that the Lord of the Bass option might be the one as it can be thinned with MEK.