laser guide

[turnerted]

Hi
I have been building a laser guided rig for deep hollowing and my little laser pointer which I bought on ebay turned up today . It makes a brilliant red spot . So I made up a holder to fit it and mounted it to my rig and all went fine for a few minutes then the light faded and went out , probably only run for a total of 10 minutes. I thought dud batteries so went off and bought another set . These also only worked for a short time then died . After a while I tried the original batteries and found they worked again for a while . what I am wondering is are these cheep lasers rated for continuous usage? It only cost me 99 cents. I was the only bidder .
Anyone else had experience with lasers ?

Ted

[bigfish]

You may be experiencing a sort of memory effect - when you drain a battery (especiallyt at high discharge rates) it can often recover slightly after resting. Try it with a mobile phone - let it go flat and shut down. Then wait a few minutes and it will power up again. I think my record is about 10 cycles like this.

Laser pointers are solid state devices and typically don't drawn a lot of power. Many SSDs do include temperature and over voltage protection but I would be surprised if this was the case in a mass produced "disposable" item - there is no value proposition in doing so.

I suspect that the design is intended to get the maximum lumens at the expense of battery life and hence high current drain. Mind you, try short circuiting a AAA battery with a paper clip - its amazing at just how much heat is generated!

You could look at a bit of disassembly with a view to connecting a plug pack in place of the batteries. Of course that may not be an option with such an expensive piece of technology!:D

If you search Youtube, you can find video showing how to power a large TV from a single AAA battery ( http://www.youtube.com/watch?v=0rA-zhTJuFU ). It works! Not for long though! :U

[Robomanic]

The laser Diode should happily run off ~3.2V. Jaycar Electronics have little battery packs which hold two AA batteries and includes a switch. It should last much longer than watch cells as AA batteries have the best capacity for size ratio.

[OGYT]

Cheers, Ted. It could be like a problem I had with some of those little Chiwanese lasers. When I'd put it in the holder, the vibration would jar the battery(s) ever downward, til the contact at the North end of the battery would barely make contact. The light would finally go out.
I would opt for the battery pack. You can get a holder from an electronics supply house, and run a wire along the hollowing rig to the Battery Pack on the ways, or taped to the Hollower. They'd last longer.

[joe greiner]

What material are you using to support the laser? Vibration can be reduced by selecting the right combinations of cross-section stiffness and length of supports (both vertical and horizontal). Might have to do some experimentation, and also find an optimum speed. YMMV, of course.

Joe

[hughie]

What material are you using to support the laser? Vibration can be reduced by selecting the right combinations of cross-section stiffness and length of supports (both vertical and horizontal). Might have to do some experimentation, and also find an optimum speed. YMMV, of course.


Good point Joe I made mine from small bore hydrualic tube, a couple of pieces tack welded to gether to improve the stiffness.

[turnerted]

Thanks for the suggestions . Looks like I had better investigate a battery pack .
Joe , I made the support out of 1/2'' allthread with the rightangle joint made of wood with 1/2'' holes drilled at rightangles .I welded up a bracket to clamp it on to the hollowing tool shaft . It all seems solid enough .
Ted