Ultrasonic flying spot scanner NBTV

[gary]

Somewhat OT but US related and quite fascinating:

http://www.youtube.com/watch?v=qy1w6rTpC2g#t=1425

[Harry Dalek]

Somewhat OT but US related and quite fascinating:

http://www.youtube.com/watch?v=qy1w6rTpC2g#t=1425

Hi Gary the thin film of soap is interesting a way of seeing the U..S beam i haven,t seen that before .

I have been stuck not on the Ultrasonic side but the polygon laser mirror monitor side of things since i don't have a spare laser printer mirror at the moment ..
as you saw in the last post i had made one out of of steel nuts and little mirrors ...i like the motor i was going to use but i think the shaft at the end is a little bent or the pulley thing on it i am using as the base , does not take much to send a laser beam off track ..

So apart from this i have been looking into polygon or multiple shapes to reflect the laser ...some of the polished nuts are not to bad which would do away with the mirrors .

What i have found is even with the best i have a which is a 4 sided high polished steel door stopper, metal mirrors defocus at distance not so much a problem for this one but of cause less sides it has higher speed you need to rotate it ...The best shape i have found handy is our 50 cent coin 12 sides...if i learn how to polish coin to a mirror finish this could come in handy ..
But i think for now i will stick with a polished nut or again one with mirrors and try again with a different motor ///
Been a bit like make it test it pull it to bits try again.

[gary]

Sorry Harry, what is the laser polygon for?

[Harry Dalek]

Sorry Harry, what is the laser polygon for?

I think for it to work i need a monitor it will have 2 nuts side by side lined up on the line speed motor ...one will reflect a laser the other the ultrasonic beam both to the frame rotating square shape which i still have to glue some mirrors to ...the laser is for a monitor the ultrasonic the camera ...bit like a nipkow monitor camera idea using the same shaft so no syncing problems ...

But i am doing it with 2 motors for the line and frame the laser and transducer are mounted side by side above the 2 nuts only reason using 2 is mounting problems .

If the ultrasonic side of things cooperate monitor camera should work at any speed really just more or less lines with motor speeds .

[Harry Dalek]

I forgot that the ultrasonic scanning beam would be picked up by another transducer close to the object its scanning and high low signal sent to its receiver which modulates the laser ...

[Harry Dalek]

Heres a test of my laser pointer and polygon nut ....its not to bad and using a pretty crappy laser pointer as well.

I ended up changing the motor for a tiny one , so far so good for over lapping laser lines ,i will see for sure at speed .

The tiny laser i am using is mounted above the nut it has adjustable focus ,i haven't got around to the second nut for the transducer yet ,just trying to remake the brackets and all for this smaller motor.

The wood square for the other scanning line direction is balsa wood pretty lite i will mount some mirrors on this as in my octagon monitor .

If all else fails least i will have a tiny version of the octagon project...

[Harry Dalek]

Not much on the postings side of things of late but have been bogged down on the monitor side of it .

I am a bit fussy since using the laser scanner mirrors saved me any errors ..in the way of misaligned laser lines in the past...

In the picture this is the best i have got so far with a glued on mirror home made idea, i tried to find out what the problem is ...you can see at the top of the laser line they spread giving a little tap to it the gap changes between the lines so it must be the mounting to the motor it does the same on the bolt idea where theres no glued mirrors so i expect this mounting must have to be pretty accurate..i must be getting a slight wobble on rotation trying to connect my mirrors to a motor connection .

So changing the motors.... mirror mounts.... so on for me direct drive of home made type mirrors is not so easy .

I am thinking of trying for the laser line drive .......mounting the mirrors on a video head or smaller size wise old HD motor ...need those laser lines to over lap.....the premade large area connections should have no wobble.

I am always going back to glued on mirrors due to the laser light loss perhaps not so much a problem with a high powered laser but i am using a not so great one for testing at the moment .

I will get on to the Ultra sonic side of things when i fixed this monitor idea up.