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Re: Polygon mirror made on the laser cutter

PostPosted: Fri Nov 23, 2018 7:57 pm
by Harry Dalek
Robonz wrote:To answer you questions Harry, here are some calculations/specs I made today.

They are not set in concrete, just an experiment for now but I will keep you updated. Its all about whether I can make some polygon and drum mirrors good enough. It certainly is a fun challenge. One thing that inspires me is I have not seen a good working Scophony replica. Maybe I missed it but that's good motivation for me. !938 style.

Cheers
Keith


I was wondering how it was going excellent idea Keith ,it is some thing that is a very much a challenge in the higher end of mechanical television ,60 lines is very doable and much easier with the mirror drums you are using ...as i recall True Scophony is a touch different Keith or there was more than one version i will have refresh of my memory and have a look what i have on file or i have posted up in the past and let you know ,i will do a search .

Re: Polygon mirror made on the laser cutter

PostPosted: Fri Nov 23, 2018 8:45 pm
by Harry Dalek
Here's some stuff on file i have found so far .
As you see in the first link below its not as easy as a 2 mirror drum system it also use's a beam converter so apart from that and as Gary mentioned on the light modulating system used its hard to call any thing that uses a mirror drum a Scophony system as it was pretty unique.
Don't let that put you off on your 2 drum system its just another way to our hobby ,a laser and 2 drums you can do many line rate and frame rates ...only limited to the drum speeds..so 60 lines is just one it could do it could do all the lower nbtv rates and higher is up to you if you if want to experiment with it ...a pulley system on the line mirror drum so as to increase the rotation with a larger pulley wheel on the motor shaft to a smaller on the line mirror drum you could triple say its speed so on so really push it and make up for lack of mirror faces for a high line system and slower motor ..just keep in mind its multi system not just limited to one line rate even to what you have in plan.
http://www.earlytelevision.org/pdf/prac ... 9-58-2.pdf
http://www.earlytelevision.org/pdf/nature_7-9-38.pdf
http://www.earlytelevision.org/yanczer_scophony.html
http://www.earlytelevision.org/pdf/Radi ... vision.pdf
http://www.earlytelevision.org/pdf/pop_sci_7-49.pdf

Re: Polygon mirror made on the laser cutter

PostPosted: Sat Nov 24, 2018 12:52 pm
by Robonz
Just a quick update. Here is the Fusion 360 cad so far.
first_cad_render.png


And yes Gary the Jeffree Cell is on the list. do you have a better picture than this to work from?
Aug38F1.jpg
Aug38F1.jpg (17.18 KiB) Viewed 3470 times


Cheers
Keith

Re: Polygon mirror made on the laser cutter

PostPosted: Sat Nov 24, 2018 3:19 pm
by gary
Robonz wrote:And yes Gary the Jeffree Cell is on the list. do you have a better picture than this to work from?
Aug38F1.jpg


Cheers
Keith


Well there is a lot on information on the cell here:
http://www.bluehaze.com.au/modlight/UltrasoundMod.htm

but you are probably aware of it.

...and here:
http://www.televisionexperimenters.com/scophony.html

Re: Polygon mirror made on the laser cutter

PostPosted: Thu Dec 06, 2018 10:24 am
by Harry Dalek

Re: Polygon mirror made on the laser cutter

PostPosted: Sun Dec 30, 2018 6:10 pm
by Harry Dalek
Heres one Troy found 1938 Scophony style mechanical Television pt1 hope it was ok to upload as you have not done this yet Robonz
link here to youtube player does not work for some reason
https://www.youtube.com/watch?v=syPK9Mu ... Q_CeYIWRB-


youtu.be/syPK9MupIaY

Edit: I have put in the correct youtube link, which is working OK - moderator.

Re: Polygon mirror made on the laser cutter

PostPosted: Mon Dec 31, 2018 1:28 pm
by Robonz
No worries Harry. I did post it earlier here http://www.taswegian.com/NBTV/forum/viewtopic.php?f=12&t=2654&p=24256#p24256

Carter gets back around the end of the month and we can get to work on the next stage being the large drum mirror. Most of the cad for the drum is done so we need to cut and assemble it next. Hopefully it runs fairly true,

Cheers
Keith