The Secret Society of Lathe Trolls

High Speed Steel
https://en.wikipedia.org/wiki/High-speed_steel

Good tip with the adhesives. I use HSS. Tungsten needles I never tried, but I have here something laying around (TIG needles) (: wanna buy a diamond in future for real cutting. Mayby I should test some stylus from farmer John to compare. My stylus diameter is 1,2mm. I try to make the degree point un...

now I made the siffnes to circa 100Nm/rad with one torsional spring. And the calculated resonance frequency should be 7,8 Khz. In reality when I emboss/impress its a little bit under 7 kHz with set screw and mounted steel (1,2mm) stylus. Because the stylus "rings" I use a little bit cyanacrylat to g...

I have to say that this is something like a try or experiment. I live in europe and it seems that theese cutting heads a rare on ebay or elsewhere. So I can't buy. And you see here now a not good working emossing head. I take only a ~0,1mm chip from the laminated iron. After that I grinded it with >...

The Frequency Response looks very poor: respnse_emboss_notIRAA_but RIAA.jpg I use components that I have and that I can get quickly. Don't have the patience to wait days and weeks for material :wink: In my little flat I only have a little turning lathe. Actually mounted in the kitchen :shock: millii...

My Armature is now 2,25g without stylus and set-screw. The resonance is 3200Hz. With a CAD program I calculated an moment of inertia of 0,041 kgmm². It's late in the night but I think this should be J = 0,000000041kgm². 1) f = sqareroot ( D / J )*1/(2pi) 2) f²*J*4*pi²=16.7Nm/rad This should be the s...

Thanks Fela. That are good to know. The Resonance is with about 3200Hz and to low. I know the physics about the moment of inertia. tonight I will calculate it. But I have concern about making the armature too thin, when removing material. And at the moment I haven't a lock screw. Try to find a M1.8 ...

... two years later but not ready :oops: I read the Pdf's and looked many pictures and patents I found. My selfmade mono head is near made to the Presto heads. It was not a big thing. A little transformator, some st37 steel, some 08/15 aluminium and two neodym magnets. In year 2019 I will buy a diam...

Hi, try it out. I don't remember if I see anyone who uses stylus-heat for embossing. I got the problem that my emboss needle is out of metal and the heat unglued my cutter head parts and the heating wire :oops: Lots of people are heating the whole disc with a light bulb or something else, I made it ...

Thanks for input. I maka a new transducer with another glue. At the beginning of making my heads, I make some cones out of alu from a beer can. Maybe I should try this again. One speaker I destroyed to look where the coil is situated. Not in the deepening at the diphragm, a little bit more in the in...

Hi Bryan thanks for your feedback (< 1)° . I read and tried to understand your OsoMiso and Groovescribe threads. Very helpful. I wonder that you got such a good phase correlation in contrast of my. I know about these capacitor and on my real (selfmade) lathe I had such of 2,2µF capacitors and parall...

Sorry I forgot to name the diagrams. the first of the spektral (fft) diagram shows the frequency response taken from the feedbackcoil. Without mixing feedback to the main-signal. The second below shows it with mixed Feedback. The main resonance is around 830Hz - 840Hz. Second(?) resonance is about 1...

I made a phase diagram out of the wave files. Limiting and mixing. The rest is to check manual out how the phase is going. I'm confusing phase.JPG The phase shift comes from +90° goes over zero at 1. Resonance and then -180° and then over -360° (2. Resonance). I can't understand it. The weight is un...

Hey I confuse the polarity of the feedback. This night I builded a mixer and added some feedback. There is no EQ in the signalpath. There are only some DC killing capacitors at the beginning of the mixer circuit. Very simple. I feel good cause it seems to eliminate the first resonance at ~830Hz. :D ...

I don't found out how to edit my text.
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Here is a picture of the driver with mounted feedback. The Coil is < 5mm diameter wound around a 3mm polythylen socket at the aluminium rod.

Hi, This forum is very helpful for me, problem is my bad english. So I read to much over :( Since a few weeks I startet to build a new head out of car speakers. This time I'm experimenting with Feedback. I make paperglued cones with an aluminium push rod at the end. These pushrod is not connected to...

Hey, I tested carbide too. There exists many kinds of it. The Problem is the dimensions of the powder/corn from which is this material is made of. I taked very fine one and tried to polish or lap it. Under the microscope I see the surface roughness. But with HSS you can get very sharp edges and a mi...

funny:
https://www.youtube.com/watch?v=byH2uWEwZg8

can you play your records backward/reverse by hand ? or is the needle jumping in another groove ? <-

thanks, so many info and answers