Reflector Beam

Reflector beams.
I thought about this for some time, toying with different ways to put it together, and decided that given the materials on hand this was the way to go.
First I had to make the initial frame which was pretty straight forward, except for making sure that the top and bottom which held the mirrors was parallel, to do this I made the top on a swivel.
That sorted, the next area I looked at was the laser, I needed some way to be able to adjust it for angle and align it centrally, for this I found a piece of electrical conduit pipe with a socket on the end, I cut two 1/4 inch pieces from the socket, and a suitable length of the pipe, slipping the socket pieces onto the end, this at first was a little tight, but rubbing the inside with some sandpaper eased it nicely. I drilled a hole in the centre of the pipe to fit the laser, which was held in place with a little super glue.

The placement of the detector, depends on where the beam end's. The circuit  was  that used in the Crossbeam article.

Adding power to the laser and trying to align the beams proved to be much more difficult than I had imagined, instead of getting a nice line of laser dots I got an arc, but by lifting the opposite end to the laser did straighten the dots to a useful degree, but the dots were not an equal distance apart. This was quite a puzzle to me at first, but on doing some research, I found out that the main problem was caused by refraction, as far as I could make out, the first  reflection bounced of the glass surface, another passing through the glass got refracted, was then reflected by the mirror surface and refracted again, this happened over and over again.
I had heard about surface mirrors, so again made a search of the internet, and found that someone making Spirographs had found a method of removing the protective coating on the back of the mirrors. So I tried this method and it worked perfect on both glass and Acrylic mirrors.

Requirements.

1. Mirrored Acrylic, or Glass Mirror.
2. "Mötsenböcker’s Lift off 5 Latex Based Paint Remover" . This is the one I found here in Australia.
Mötsenböcker’s doesn't damage the mirror surface or the acrylic at all. You have to let it sit for awhile though, about 5 - 30 minutes. You shouldn't have to "rub" to get the paint off, if you let it sit long enough, the paint will just float off.
3. Once the paint cracks up, remove it from the lift off and rinse under running tap. the liquid can be returned to it's container for  reuse.
4. let it Dry, then polish lightly with soft cloth to remove any water smear.
Another product that works equally well is "Winning  Colors Stain Remover". ("not found here in Australia").
Both are available in the USA.

Ok, here's the big question ("Did it work ?") Well yes in the first instance, to a fashion that is, but not how I wished as explained above, but since using the surface mirror idea, things have changed.

I still got the arc, but with a bit of adjustment of the Laser itself, it worked fine, it does take some fiddling but the end result is pretty good, I managed to get the gapes between the beam dots to about 1/2 inch apart.

Not sure how this would work on a larger scale, it may need to use two laser’s.

Being as my Olympus E520 camera has a shutter lag of 500ms I can’t do any real trials outdoors, But I am in the process of making a unit via an Arduino that will allow me to use the Panasonic FZ50  which they tell me is pretty quick, time will tell.

This photo was taken before I changed the mirrors

Here are a couple of examples taken in the dark via flash, will try to add some real-time camera shots later

Crossbeam

 

Crossbeam Sensor.
As you can see form the images below, the frame is made from plastic water pipe, I tried electrical conduit but found it to be too flexible. Using pipe for frames is of course  not new, so I will not take any credit for the idea, also the crossbeam was also made by someone else as well, but where mine differs is I have used lasers instead of infra red, because the lasers will work over larger distances, and are easier to align. also the original idea had the wire affixed to the exterior of the frame, held in place with tape. Though my idea takes a little longer to construct, I believe it to be much neater and more efficient.
Size of the frame doesn't matter to much, it can be as small as two inches or large enough to catch larger animals walking through it. Though a larger size I would think, would need a bigger diameter pipe.
Start by cutting four equal lengths of pipe, mark the centre's and drill holes in two of them to suit the laser modules you are using, in the other two drill hole to suit which ever detector you plan on using, I chose Photo resisters (LDR"s) simply because I had them on hand, but phototransistor's will work as well, maybe better. Directly behind these holes I made a cut out  with a dremel type tool so as to be able to get at the circuitry, not that there is much involved in mine, it depends on the voltage requirements  of the laser modules to be used.
Wire up the circuitry and thread it though the pipe and corners, measure the distance from the centre to the bends making sure they are all equal, once it is all in place line up the lasers and detectors, by twisting the pipes, and tweaking the components, adding power to the laser's will be a great help, once aligned put a little super glue against them, and some hot glue to hold the pipes in place. Attach inline 3.5 sockets to the leads and where done.
I wonder if we could parallel more lasers and LDR's, I might give it a try.
I had tried a crossbeam before, using a none microcontroller unit, and found that to trigger it you had to break both beams at the same moment, but with this one it doesn't matter which beam you break it will fire, I thought at first that this was because the Camera Axe was  turning off the lasers, but on testing this with my Arduino Prototyping setup, i t performed in the same way, and it is not set to turn off the laser's.
I took a couple of pics with it, I just threw the model through the beam, I know it is not very well focused, but it proved it worked. I set a 70ms delay. this would depend on how fast the subject was moving, I haven't tried it, but should imagine that dropping a heavier object through the beam  would increase the speed, thus the delay. My object at 70ms only travelled about 4-5 inches.
On reflection, as this stands it would be very hit and miss for insects, there is too much space around the beams, But if you were to make one on a much smaller scale say 2 inches square, and set it close to a flower then maybe it would be ok.
I think my next project would be much better.
 
 
 

 

 

I haven't as yet tried it in real life situation, it would  more than likely take much
more trial and error in setting up, to allow for shutter lag etc..
Link to Lasers below.
https://sslrelay.com/odicforce.com/shop/article_OFL85/New-Micro-Red-Laser-Module---5-Pack.html?sessid=C9hMotrTiiwudszXISr2qYXzizv2Cb4Tv5wjeRvhzYQqUKIGLGOmpt4NK4fyjM8I&shop_param=cid%3D13%26aid%3DOFL85%26
Hope someone will find this useful.   Ernie

Getting started

Nov 09 2010.

About 12 months ago I found some info on High Speed Photography, and decided that I would like to get into this.
I tried some electronic circuits, which worked quite well, but each module was a seperate item, and I found setting delays was quite a pain.
So I made a search , and found DreamingRobots.com where the owner Maurice Ribble had done a lot of work with the Arduino Microcontroller board, there were a lot of different projects to wet ones appetite.
Having played around with the Arduino, I decided this was what I was looking for.
With a lot of breadboarding I finally came up with three sensors, Sound, Lightning, and photogate, all working as one unit with the Arduino. I designed and made a circuit board to handle all three sensors each with there own input, and outputs for three Flash units or camera. The threshholds and delays were set by potentiometers.
My biggest problem was the programing side of the project, but with examples on Maurice Ribbles site, and, much trial and error I got it all working, be it some what touchy.
In the meantime Maurice developed a unit ( The Camera AXE ) which left mine for dead, I could never dream of adding the sophistication of his software, so I purchased one along with some of his sensors. Now I have developed some sensors of my own, which I will be writting up here, very soon, along with pictures, I hope you find them of use.