The farmer and his plow - When I set out to build a record cutter

[farmersplow]

Hello Thomas, very happy to help you test the machine out if you'd like to just ship it over to me here in America, not a problem at all. All kidding aside, very impressive as usual, it's as beautiful as it is technically proficient. Excited to hear more samples, what a testament to craftsmanship!

I was about to ask if I could send it to you for testing. Then I realised that I couldn't get it through the door. I'm glad you like it. I'll send you more audio samples soon. Greetings to Philadelphia.

[farmersplow]

I want to see what I hear! - Microscope second attempt

A new design should eliminate the weaknesses and ensure good operability.
So back to the drawing board, the lathe and the milling machine.
First I build a slightly longer arm to hold the microscope part.
Everything has to be stable!
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VIDEO:

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VIDEO:

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A new holding element also has to be made.

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VIDEO:

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Now I have to build a new, longer holding cylinder. Good cords can be used to create a non-slip surface.
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Greetings from Austria
Thomas

[farmersplow]

I want to see what I hear! - Microscope second attempt

I also fitted a spring-loaded piston and a micrometer screw into the construction. This means that it is now possible to precisely adjust the height of the entire support arm by turning the micrometer screw and thus focus can be set.
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In this short video, the damped spring load can be easily recognised.
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VIDEO:

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Assembled with the microscope it looks like this:
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Greetings from Austria
Thomas

[farmersplow]

I want to see what I hear! - Microscope second attempt

It looks much better when installed. I have mounted a lamp on the support arm.
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The following video shows the focusing:
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VIDEO presentation of a test groove:

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Greetings from Austria
Thomas

[markrob]

Hi Thomas,

Looks pretty good. The cost of the scope is reasonable. What is the optical magnification you are running at here? What is the groove LPI we are seeing? Does the software that comes with the scope allow for calibration and measurements? Any ability to create a custom video overlay?

Mark

[farmersplow]

Hi Thomas,

Looks pretty good. The cost of the scope is reasonable. What is the optical magnification you are running at here? What is the groove LPI we are seeing? Does the software that comes with the scope allow for calibration and measurements? Any ability to create a custom video overlay?

Mark

The magnification used is 700x.
I don't know the groove spacing of this image for sure - it's been a while and I don't have any records from back then. (Either 120µm = 210 LPI or 150µm = 170 LPI). At the end of this ‘microscope’ article I plan to show some pictures with actual measurements and dB values. Then I can say exactly.
The supplied software allows only minor calibrations and measurements. It is possible to display defined horizontal and vertical lines in different colours and thicknesses. These can be positioned precisely on the screen. However, you can only take measurements if you place a reference measure (measuring strip) underneath. Then you can calibrate and measure.
Is that what you mean by a customised overlay? This also works with video. You can record videos. An overlay (as with smartphones) directly in the microscope for videos is not possible.

[markrob]

Hi Thomas,

Thanks for the explanation. 700X seems optimistic. How is that determined? From what I can see there are about ten grooves on the screen at a spacing of about 200 lpi. So you see about .05" of distance. If the screen is 10" diagonal, then I calculate about 200X. Is there any digital zoom being used here? It can be hard to separate the true optical magnification in one of these scope cameras. I'm also not sure how the definition of magnification is determined. Is it based on the size of the sensor dimensions and the distance displayed?

The software I'm using (ToupView), lets you do a calibration using a reference ruler like yours. Then you can read distances by out distances in real time by defining line endpoints. It has quite a nice set of features. Here is a link to a short video showing how this is done.

https://www.youtube.com/watch?v=j9fBjG14P5U

The software may work with your scope. You can download it here:

https://www.touptekphotonics.com/download/

Mark

[farmersplow]

... 700X seems optimistic. How is that determined? From what I can see there are about ten grooves on the screen at a spacing of about 200 lpi. So you see about .05" of distance. If the screen is 10" diagonal, then I calculate about 200X. Is there any digital zoom being used here? It can be hard to separate the true optical magnification in one of these scope cameras. I'm also not sure how the definition of magnification is determined. Is it based on the size of the sensor dimensions and the distance displayed?

The software I'm using (ToupView), lets you do a calibration using a reference ruler like yours. Then you can read distances by out distances in real time by defining line endpoints. It has quite a nice set of features. Here is a link to a short video showing how this is done...
Mark

Hello Mark,

Thanks for the additional information. 700x is indeed optimistic and I used the manufacturer's specifications without doing more detailed research (I wanted to do that). In fact, even your 200x is optimistic! I quickly calculated 100x. I will have to analyse what is correct with further tests once I know the parameters. I will also try to find out how strong the optical and digital magnification is.
Your tip with the calibration software is great! I will check over the holidays whether it can be installed on my microscope. That would be a real gain.

Thank you
Thomas

[farmersplow]

Merry Christmas

[farmersplow]

I want to see what I hear! - Microscope second attempt

This is how the microscope is moved, i.e. brought to the desired position via the plate groove:
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The video shows the observation of the groove during the cut:
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Greetings from Austria
Thomas

[farmersplow]

I want to see what I hear! - Microscope second attempt

The groove can be viewed closely with the microscope.
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VIDEO:

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Photos and videos can be taken at any time using the remote control.
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Greetings from Austria
Thomas

[zdenek]

How do you measure the actual width of the groove? Have you seen the magnification of my microscope?https://www.youtube.com/watch?v=bwzHBUGGtrA

[farmersplow]

How to measure the grooves:

Looking at the grooves under the microscope is a beautiful thing in itself. Almost all things look beautiful under the microscope, probably because the images show us a world that we do not recognise.

In most cases, looking at the grooves is enough to check that there is enough space between the grooves and that there is no overlap. Sufficient land between the grooves!

When setting up the lathe and the cutterhead, it is also necessary to know the groove depth (usually = groove width/2) and the groove spacing.

In my case, the microscope has three different lenses. The ‘strongest’ lens must be brought very close to the surface of the record (4 - 5mm). I only use this lens to check the diamond stylus. The reason for this is the small image section and the fact that it is difficult to illuminate sufficiently to get good contrasts.

Here is a picture of the three lenses and a shot with the strongest lens (~700x magnification) of the Ortofon test record Left channel only 1000Hz:
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For groove measurement I only use the centre lens with a distance of about 12mm to the record.
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Measure grooves:

Measuring means comparing!

First, I use a calibration film that I place on the record:
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Then I set the microscope to my usual magnification, focus the image and take a picture of the calibration film with the microscope. I take a picture of the scale (4 lines = 1.5mm = 1500µm). I also take pictures of the line thicknesses on the calibration film (0.076mm; 0.1mm; 0.5mm).
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The microscope is supplied with software. This software is accurate and the calibration process works well, but afterwards the software hangs and I have to restart the program. Maybe because I'm using Windows 11? Never mind.
In the software, the image is imported, can be enlarged and reduced and then a measurement between two points is marked and the value (in my case 1500µm) is saved. This completes the calibration process. (Several calibration values can be saved).
The official software and user manual can be found in the manufacturer's download centre https://andonstar.com/download/ . Many other functions are also described there, but I will not go into these in detail.

The measurement can be checked in the measurement function of the software. To do this, select an image (in my case the same image I used for the calibration) and mark a measurement between two points. The measurement is then displayed on the screen (1504µm). So it fits.
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I do further tests with the lines 0.076mm; 0.1mm; 0.5mm:
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To be continued:

Greetings from Austria
Thomas

[Thelatheofus]

Wow that second image looks amazing !

[zdenek]

I don't know how to measure the width of the groove with the lens fixed at an angle, as it looks like in your second photo. I have to have the microscope positioned completely perpendicular to the vinyl record for the measurement to be correct, this is what it says in the manual of the old microscope I used. Can you make a recording with the highest magnification lens of your microscope?
And anyway, it's not the most important thing, what matters is what you hear and how you hear it.

[farmersplow]

Wow that second image looks amazing !

Thank you very much. I like it very much too. This is the largest magnification possible, apart from the additional 3x zoom function. But the picture doesn't get any better, just bigger.

[farmersplow]

I don't know how to measure the width of the groove with the lens fixed at an angle, as it looks like in your second photo. I have to have the microscope positioned completely perpendicular to the vinyl record for the measurement to be correct, this is what it says in the manual of the old microscope I used. Can you make a recording with the highest magnification lens of your microscope?
And anyway, it's not the most important thing, what matters is what you hear and how you hear it.

With the analogue microscope it will be difficult to measure diagonally. As a rule, analogue magnifiers have a scale in the optics. With some microscopes you can also rotate them. Some do not.
With my digital microscope, I can define two points between which the distance is measured (or circular scale, etc.). Each system has advantages and disadvantages.
No single part of a complex lathe is the most important part. But a microscope should not be missing from the overall concept.

[zdenek]

The photo of the groove you presented looks like from a scanning microscope because there are no light reflections visible. Is your microscope a scanning microscope?https://thevinylfactory.com/news/incredible-photos-of-record-grooves-under-an-electron-microscope/

[zdenek]

I'm asking you because the photos I obtained from a similar microscope to yours are as you see.What does it depend on?

[farmersplow]

I'm asking you because the photos I obtained from a similar microscope to yours are as you see.What does it depend on?

My microscope is not a scanning microscope but as described above. The result depends on various factors.

A: The material. Different materials give different results. The photo above was taken from the Ortofon test disc (VINYL). PVC looks different and so does PET-G. There are also differences with PET-G. With sandwich PET-G (black film between two transparent PET-G sheets) there are reflections (artefacts). These do not exist with black PET-G. Transparent blanks look different again. I will provide some examples in the next reports.

B: The light. The result looks different depending on the lighting. With a ring lamp (circular around the lens), the image is illuminated from all sides. Circular LED makes many single points. Usually 6-10 LEDs are used, which results in a 6-10 cornered illumination and therefore also inhomogeneous reflections, which have an influence at high magnification. The light intensity must also be adjusted so that there is no overexposure. With a light source, the angle at which the light shines on the groove must be selected so that as few shadows as possible are created.

C: The microscope. There are of course many differences.

My example from the picture above:
Here I have looked at vinyl and aligned a strong light source along the groove. If you look closely at the two grains of dirt in the picture, you can see that the light source is coming from the left-hand side.

Additional information:
I found a test cut in my archives that I made with my old digital microscope. Apart from the fact that the section is not good, you can see the reflections of the ring illumination (8-LEDs). Then the image looks similar to yours (only not as magnified).

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