NBTV Television Project Help

[McGee2021]

So is it still possible to get some sort of image on this disk?

You could get an image of of this disk if you install lenses and acquire a crater lamp.

[gary]

So is it still possible to get some sort of image on this disk?

You would get a very crude image at best.

However, if you bought some of these:

http://www.delviesplastics.com/acrylic_balls.htm

and pooped them into the holes (as a force fit no glue required)

Then provided your holes are accurately centred you will get a very bright crisp image indeed.

Best of all you will need only one ultra high brightness white LED (available everywhere now).

It would look something like this.

download/file.php?id=2756

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

(note the annoying bars are an artefact of recording 12.5 fps at 30 fps and are not present when viewed by eye.

I personally believe that this is the easiest way to construct a Nipkow based television monitor.

PS The link to the optical balls given above has a minimum 1/4" but I also use 3/16" and 1/8" which you will find somewhere on the internet I am sure.

Sorry about the imperial measurements but they all appear to be manufactured in the US.

Again I repeat the result you get will depend highly on how accurately you have positioned the holes - it does for a a standard aperture Nipkow disk too.

Good luck!

(Oh as an old Electrical Engineer with 40 odd years of experience - please consider becoming a certified accountant (or similar) instead - you will have less stress, more money, and definitely more success with the girls!

[reshiram202]

I live in the US so its fine. I already made a new disk with much smaller holes. I thought I already posted a picture about it but I guess not.

[gary]

I live in the US so its fine. I already made a new disk with much smaller holes. I thought I already posted a picture about it but I guess not.

Yes you did but it seemed to be using thick corrugated cardboard like the first - that's another problem that is solved by using the beads.

BTW the beads (or balls) are readily available and CHEAP in the US. But it is good to make a standard Nipkow disk first even if you go onto making the bead disk, so you can compare the difference, however if you use anything greater than say about 1/16th of an inch thick cardboard you will only see an image when your eye directly is in line with the hole and even then the outer parts of the image will probably be much dimmer. When it comes to standard Nipkow disks thinner is always better.

[McGee2021]

I live in the US so its fine. I already made a new disk with much smaller holes. I thought I already posted a picture about it but I guess not.

Yes you did but it seemed to be using thick corrugated cardboard like the first - that's another problem that is solved by using the beads.

BTW the beads (or balls) are readily available and CHEAP in the US. But it is good to make a standard Nipkow disk first even if you go onto making the bead disk, so you can compare the difference, however if you use anything greater than say about 1/16th of an inch thick cardboard you will only see an image when your eye directly is in line with the hole and even then the outer parts of the image will probably be much dimmer. When it comes to standard Nipkow disks thinner is always better.

I think the only problem so far would be the way he mounts the disc to the motor. He would need some strong method to connect it with only one hole.

[Klaas Robers]

(Oh as an old Electrical Engineer with 40 odd years of experience - please consider becoming a certified accountant (or similar) instead - you will have less stress, more money, and definitely more success with the girls!

That might be Gary. But imagine and reflect what you think that is important for you?

For our young and enthousiastic guys, think of this:

If you want to have large amounts of money, a castle to live in, a big and expensive car, a boring life with lots of stress and no time to enjoy the money, this is indeed what you should do: Go into business and/or the financial world.

But if you want to have an interesting job, which brings you enough money to have a good life, a reasonable home, a real hobby and a good car that brings you wherever you want, be a technician (in electronics or what else) and refuse to grow into a managers role. Stay in engineering. That is exactly what I did.

Technicians are making the future world. Look around. All those technical things are invented and designed by technicians. Don't you want to be one of them?

[McGee2021]

(Oh as an old Electrical Engineer with 40 odd years of experience - please consider becoming a certified accountant (or similar) instead - you will have less stress, more money, and definitely more success with the girls!

That might be Gary. But imagine and reflect what you think that is important for you?

For our young and enthousiastic guys, think of this:

If you want to have large amounts of money, a castle to live in, a big and expensive car, a boring life with lots of stress and no time to enjoy the money, this is indeed what you should do: Go into business and/or the financial world.

But if you want to have an interesting job, which brings you enough money to have a good life, a reasonable home, a real hobby and a good car that brings you wherever you want, be a technician (in electronics or what else) and refuse to grow into a managers role. Stay in engineering. That is exactly what I did.

Technicians are making the future world. Look around. All those technical things are invented and designed by technicians. Don't you want to be one of them?

I plan to be an electrical engineer, and i already have a place being held for me at a company, so no problem so far!

[reshiram202]

No I have an newer one with much thinner cardboard and very small holes. I thought I posted it but, oh well.

[gary]

Fair enough, so it was Scanning disk mark III? Anyway good luck with that.

[McGee2021]

Just one last thing, make sure you have everything put together properly and strongly!

[reshiram202]

No it is a mark II but I thought I had posted the image here but it appears it didn't.

[gary]

No it is a mark II but I thought I had posted the image here but it appears it didn't.

No it IS here but you have to open it up in a viewer - I have done that but the cardboard still looks quite thick and corrugated. The cardboard type you want is like the cardboard you find left over after you have used all the pages of a note or sketch pad, or poster cardboard. You want something no thicker than a CD or DVD (indeed they have been used as a Nipkow disk but produce a very small picture). Also realise that a Nipkow disk doesn't necessarily have to support it's own weight, it can be floppy because when you spin it around at 750 RPM it straightens out.

But hey! We are telling you things from our own experience - but there is NOTHING wrong with using the materials you have there AS A STARTING POINT, just don't be too disappointed with the results, if you get any recognisable picture at all - even if it is just a shadow or silhouette you are at least treading the same path as the original pioneers and that should make you proud and happy. After that you can say, "what can I do to improve things?" and go from there - the sky is literally the limit. Just always remember, when it comes to aperture type Nipkow disks thinner is always better, and accuracy even more important for good results. Good luck.

[reshiram202]

It is actually thinner than notebook cardboard. I don't know, maybe I can make this work. All I know is is that using my computer monitor as light and spinning the disk on a screwdriver shows a lot of black lines. Maybe because it isn't up near 750 rpm? I don't know. Planning on upgrading to maybe 45 lines and make a camera.

[gary]

It is actually thinner than notebook cardboard. I don't know, maybe I can make this work. All I know is is that using my computer monitor as light and spinning the disk on a screwdriver shows a lot of black lines. Maybe because it isn't up near 750 rpm? I don't know. Planning on upgrading to maybe 45 lines and make a camera.

Ok, it certainly looks thicker than that on your picture, and I have never seen corrugated cardboard that thin, but if you are happy with it that's fine.

You will get black lines if the spacing between holes (we call them apertures) is wider than the aperture size, theoretically the spacing between the apertures (along the radius) should be the same as the aperture size - in practice some prefer to have some overlap to mitigate the dark lines cause by the fact the apertures are circles not rectangles. Some line structure is normal with a raster based monitor.

Personally I think you should persevere with what you have for the time being - mount it on a motor (this is one drawback with the shape of your disk - with a round disk it is easy to *carefully* place your finger on the edge of the disk to slow it down [nearly all motors spin faster than 750 RPM] - there is much to be learned by using this method as a first iteration). Just a small toy DC motor would suffice for your first attempt.

I STRONGLY suggest you stick to NBTVA standards, and build a monitor first, as this will allow us to provide you with more advice and help. Later on, when you are more proficient, you can do your own thing with more confidence.

Note: Building a camera is significantly more difficult than building a monitor.

[reshiram202]

I probably won't be able to finish everything until mid 2016 anyways because of other projects I am currently working in the meantime. Hopefully my little breadboard can make this happen.