Robonz wrote:Harry,
Cutting the pockets causes a small amount of warp in the acrylic. I do want to try annealing it in the oven to see what happens. I do have a spare disc to play with now too.
Good to experiment and see this Nipkow made your way was new to me
Yes, I do have an old VCR here for parts, but for now I like to try making all the bits myself. It adds to the mechanical challenge. I am designing new optics for my laser cutter to get the beam really exact so I can laser cut the hub directly. Hopefully It works! Right now if I laser cut hubs they wobble bad.
With your laser cutting gear well worth it i am sort of suck with a drilling hot gluing re purpose what ever i have scrapped .
How small can you make a hole Keith out of interest if you know ? be very useful for higher line rates beyond manual drilling cnc drilling
Seeing as I can make these Nipkow discs without a huge effort I have been considering making a double or even triple spiral to make the picture bigger. I have not seen many people do more than one spiral. Any advice or ideas on that? I do realise the speed has to double or triple. Getting rid of the magnifying glass with a large image would make it look really cool. Plus you get the nice drum behind the Nipkow disc.
Cheers
Keith
Yes that's a good idea.. i know Holtzman did a 2 spiral 60 line with a interrupter bit like the 2 drum monitor ...apart from that only bit of talk .
To get true size with a mechanical monitor either you have to make it bigger or have more light to project to ...or have a 2 drum or disk idea .
Yes it depends on number of slits or holes half the number twice as fast so on ,its a toss up between size wanted and speed you can do and line number ..
With your laser you could cut fine nice line or holes ...i had to do mine with a Stanley knife and black light proof paper...you could sure do better than that a 2 disk monitor would be a lot easier if you don't mind the line curve .....drum you get the correct look for size i am sure the curve would show up on a disk version worse than a Nipkow ...having said that i wouldn't mind seeing one always had in mind to try it .
There's lots of versions of what you have in mind google patents give you a good idea of what has been tried if you want to look i have a lot of file ...so you planning a Drum disk idea i would say i would go slits instead of a Nipkow one you can go multi system for a start if you are going to the trouble of a 2 motor version .
I would make the framing motor always a stepper due to the slower speed and keep the line disk or drum DC for the high speed needed ...also if you go this way a pulley system for the line side of it you get extra speed out of your dc motor for higher line rates ,Doms software does 30 32 48 60 64 line and the new software up to the low 100's any line rate you want what better way to test the mechanical monitors limits !