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Re: 0 to 360 degree camera and MORE!

PostPosted: Thu Sep 15, 2016 1:40 pm
by Harry Dalek
Viewmaster wrote:
Harry Dalek wrote: small and having mucked about with this stuff pretty hard get to work accurately and smaller


Yes, Harry, accuracy is king. The 45 degree mirror angle has to be spot on.
The line mirror axis has to be exactly 90 degree from frame mirror axis.
Unless both of these are correct then scanning lines will not be straight.

This first rig may not be up to that but it will work, albeit with some image distortion.

That in itself might lead me to play around with large deliberate distortion ........
.....but I don't want Paul Nipkow to turn in his grave.......... at 12.5 revs. :D


Hi Albert hats off to you i know it does not take much when trying to make a mirror swing in a correct arc for it to be a touch off due to mounting lining up it can be very frustrating !

Klaas mentioned once its easier to repurpose things than make them from scratch for me i find that works as i am not good at the first and don't have the tools and skills .
So on this ....i like mirrors if i can be already lined up and mounted ...thus i always pick up those dead laser printers on the side of road when i need a polygon mirror but they are going cheap these days down to a square mirror ! .,,,,,,that works for the line mirror for me the hard one ...the frame i tend to make and after lots of trying i found the mirror surface you placed it on needs to be simple and accurate i pick a square ...lego block or what ever that is accurate and never glue behind the mirror even with a thin film of glue its enough to throw that mirrors reflection off .

Good idea keep improving where you can some times you only see it needs it when you have made something ,but yes see how you go with this and the results it gives,

Re: 0 to 360 degree camera and MORE!

PostPosted: Thu Sep 15, 2016 9:27 pm
by Viewmaster
Latest progress.........back to the drawing board ! :D

More anon.

Re: 0 to 360 degree camera and MORE!

PostPosted: Mon Sep 19, 2016 2:26 am
by Viewmaster
The long frame mirror is too non linear so MARK 2 has been constructed.

Still keeping the high speed 45 degree mirror for line scan but now
going back to a rack and pinion for frame.

A slower down scan and a fast flyback back to the top of the frame now works OK.

If I allowed the laptop to draw the flyback I would be going 405 line TV nostalgia. :)

Photo to follow.

Re: 0 to 360 degree camera and MORE!

PostPosted: Wed Sep 28, 2016 6:19 pm
by Viewmaster
Here's the new system. The 45 degree fast spinning mirror is mounted on the arm actuated by rack and pinion (white)
3 cheap bought PWM boards on left. One for 45 mirror and 2 others for frame scan and other for fast fly back.

Relay board in centre and ADC on right. Large cable is to laptop input printer port for video and sync pulses.

I wired the 28 pin ADC with narrow socket and then shock, horror found it was the wider version required.
So new socket is piggy backed onto old now.

The biggest problem is super glueing that tiny mirror at exactly 45 degree to get a perfectly straight line scan.
Getting there though.



Image

Re: 0 to 360 degree camera and MORE!

PostPosted: Wed Sep 28, 2016 11:09 pm
by Harry Dalek
I like the look of this version of your invention Albert .

I will look forward to seeing a future test run . :wink:

Re: 0 to 360 degree camera and MORE!

PostPosted: Wed Sep 28, 2016 11:28 pm
by Viewmaster
Harry Dalek wrote:I like the look of this version of your invention Albert .

I will look forward to seeing a future test run . :wink:


That's quite some distance in the future.

All the very best designs have either a piece of string or an elastic band
integrated into the design to make 'em go, Harry.

Note my blue elastic band used to keep the rack in contact with the pinion.........
Aw, and a couple of drawing pins too.
That blue colour doesn't necessarily reflect my politics. :lol:

Re: 0 to 360 degree camera and MORE!

PostPosted: Thu Sep 29, 2016 9:09 pm
by Harry Dalek
Viewmaster wrote:
That's quite some distance in the future.


I will be waiting ! :wink:

All the very best designs have either a piece of string or an elastic band
integrated into the design to make 'em go, Harry.


I tried the elastic bands Albert a little to stretchy i am keen on rubber bands for pulleys :D
I am not sure of your speed for the vertical scan here is a video of a idea i had for SSTV vertical scan off center wheel on a microwave oven plate motor.i was going to try it for either a direct camera or a laser flying spot so sort of similar scanning in a way on yours

Note my blue elastic band used to keep the rack in contact with the pinion.........
Aw, and a couple of drawing pins too.


Well if it works use it i say and you never know unless you try it is the way of the prototype :idea:

That blue colour doesn't necessarily reflect my politics.


Well thats good to hear its not my colour either but for a project why not :wink:

Re: 0 to 360 degree camera and MORE!

PostPosted: Thu Sep 29, 2016 11:30 pm
by Viewmaster
Never use elastic bands for any drive system. My band is only to pull a rack onto a pinion.
Any belt drives I have ever used have been toothed belts.

You seem to use everything available to make NBTV, Harry.
Microwave overs but not yet used the kitchen sink though :lol:

Here's the line sync idea I had. Tiny piece of polished steel reflects laser onto photo diode. In this was there
are no vibration problems one would have with a high speed running opto disc. The brown mount can be swivelled to give
any angular line pulse position and so vary start of image scan. (panning image)
I get a good pulse off this reflection.

The 45 degree mirror is about 1/4 inch long.

Image

Re: 0 to 360 degree camera and MORE!

PostPosted: Wed Oct 12, 2016 7:19 pm
by Viewmaster
I have now given this machine a name, "The Lapkow."
Any further news etc will be on the new thread.