Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

Buy Site Supporter Role (remove some ads) | LPF Donations

Links below open in new window

FrozenGate by Avery

Laser Harp laser

Tha Greenlander said:
Well the tape method may not be the best way, most of the time the output power will vary slightly.
Click to expand...
Yeah, it's just for my own amusement so it doesn't really matter that much, if it gets to be a problem I may be able to just take it apart and replace the pushbutton with a toggle switch, i'll keep my eye out for one that already has it though.
 





albuser said:
Yeah, it's just for my own amusement so it doesn't really matter that much, if it gets to be a problem I may be able to just take it apart and replace the pushbutton with a toggle switch, i'll keep my eye out for one that already has it though.
Click to expand...

Alright, keep us updated :san:
 
albuser said:
I don't think the laser needs to turn on and off at high speeds, the idea is the beam is continuous but when you place your hand over it the photoresistor will read it and tell the processor at what stage of the stepper motor the signal was read, the stepper motor is creating the split beam effect not the laser itself
Click to expand...

The laser most definitely needs to turn on and off at high speeds (depends on the galvo speed) to produce the fan of multiple beams, otherwise it'll just be one beam producing a giant fan.

Look up "blanking" it will explain why the laser needs to be off.
http://nqlasers.com/scannerreference/index.php?title=Blanking

Think of it this way, you are projecting a dot pattern, without blanking the laser will fill the space between the dots, producing a straight line.

albuser said:
I think a LAB laser is more than I really need, thanks for offering though
Click to expand...

A lab style laser would be perfect for this project.
 
Last edited:
FlutterPie said:
It seems like it would be perfect. Its not big at all (quite small actually). And has a 100% duty cycle. Anyways I was just offering.
Click to expand...
If you'd be willing to let it go for cheap enough i'd probably be willing to buy it but i've got a pretty limited budget so I don't think I can offer you a fair price for it
 
ARG said:
The laser most definitely needs to turn on and off at high speeds (depends on the galvo speed) to produce the fan of multiple beams, otherwise it'll just be one beam producing a giant fan.
Click to expand...

But isn't that why i'm using a stepper motor? The speed of the motor in between each step should ensure that you don't perceive the laser in between each step, and due to persistence of vision you only see the beam at those specific steps. I haven't looked the code over thoroughly enough to see if that's indeed what it's doing that's just what I gathered from the instructions, I could be wrong though.
 
Are you saying that a stepper motor is faster than a light beam and can move the beam through space so fast that it can produce blank spots, keep wishing.

I think light might be just a little faster than something mechanical :thinking:

Your going to need a laser with TTL capability if you want to do this project I believe, other wise you going to get one fan shaped beam out of your stepper motor.



albuser said:
But isn't that why i'm using a stepper motor? The speed of the motor in between each step should ensure that you don't perceive the laser in between each step, and due to persistence of vision you only see the beam at those specific steps. I haven't looked the code over thoroughly enough to see if that's indeed what it's doing that's just what I gathered from the instructions, I could be wrong though.
Click to expand...
 
Last edited:
Flaminpyro said:
Are you saying that a stepper motor is faster than a light beam and can move the beam through space so fast that it can produce blank spots
Click to expand...
Haha not exactly, I just figured that since the stepper motor stays on the steps for longer it would reflect alot more light at those specific intervals and not so much in between them, there'd still be light reflected in between them but because it's not reflecting as much light as the steps you wouldn't see it nearly as clearly. It looks like he's using something with TTL in the first picture but later on I think he has a picture with just a regular handheld one.
 
albuser said:
But isn't that why i'm using a stepper motor? The speed of the motor in between each step should ensure that you don't perceive the laser in between each step, and due to persistence of vision you only see the beam at those specific steps. I haven't looked the code over thoroughly enough to see if that's indeed what it's doing that's just what I gathered from the instructions, I could be wrong though.
Click to expand...

Stepper motors are pretty slow when compared to galvo's. The answer is yes, you will still see the beam in between the steps, though it will be dimmer.
 
You guys are right, the code has the laser turn on and off for each step of the motor, are you sure that that can't be done with just a handheld laser though? He never says you need TTL and he even uses a handheld laser in most of the pictures.
 
so i was looking at the code given for this project. it has variables in it to control and store the state of the laser. This means the TTL laser is needed for this as said before. The laser turns of whenever motor moves and turns on when finished. hope this helps
 
Last edited:
with additional circuitry a handheld might be useable, but some handheld laser moduels can't be modulated fast enough since they are made for CW operation. Some drivers have soft start which would prevent modulation. You would then also have to deal with the short duty cycles.

The right laser for this job is a TTL or analouge lab style laser.

Your choice.
 
Ok thanks, i'll see if anyone's willing to part with their lab for something I can afford, i'll probably just have to go for a lower wattage
 
You must log in or register to reply here.


Back
Top