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3w laser for beginner build

badboybilly

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Hi I have had this laser for more than a year it was one of my first NDB7875
I haven't got pics of the inner workings, but I'll explain for anyone interested in making an easy quality first laser,

So it's mainly just an aluminium bar with a 12mm whole straight threw the centre, great heatsinking, an NDB7875 9mm diode with a 2.4a xdrive from DTR attached straight to the diode,
it was pressed in with a vice were I managed to damage The threading for the lens, so the top cap is the focus cap from DTRs 510 adapters witch was thermally attached to the bar focused to burn at 5 meters, so it's no longer adjustable, due to damaging the lens threading,
these diodes are awesome, and I must have one of the best G2 lenses I have seen there is absolutely 'no' artifacts around the beam dot and burns everything.

For the positive connection a hardened plastic plug with a brass screw screwed through the centre soldered and heat shrinked on the rear and very tight fit,
But before pressing all the way in the negative wire was attached to the side of the plug.

The switch took a little moding not much to explain there just look at the pic, I don't think it's possible to have the light in the switch light up as you press in this situation I tried many different ways, anyway the switch is a nice touch that
Compliments the laser, it just slides in and out for easy access to the batteries,

It's nice and tight so won't fall out,
Well there you have it a very easy and effective looking laser to build for anyone looking for an easy build.

Thanks for looking!
 

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VirtueViolater

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Sweet! Simple and effective. How many builds do you have under your belt Billy?
 

badboybilly

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Not that many bro
There all on my sig except the last one the Tank007
12 I think!
 

monkeydan

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lol are you sure 3W is for beginner? Anyway, you have another nice build :gj:
 

badboybilly

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Really have you tried changing from lightweight to darkshadow or default you now the forum views!
 

OVNI

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... I don't think it's possible to have the light in the switch light up as you press in this situation I tried many different ways ...
I posted this diagram of a host with two switches, one 'clicky' in the back that switches the batteries ON and OFF, and the other a momentary switch which connects the batteries to the Laser Diode Driver. It shows the wiring to the back of a switch that looks like yours. This might help you figure out how to use your switch. Are you using a momentary on yours? To get the LED to light up is not hard, I can walk you through it if you want to pursue it. Just send/post a picture of the back of your switch if it's different than what I posted.

I also recently came across this DynaOhm™ Variable Resistor that keeps the current level to the LED part of the switch constant even as the battery goes from fully charged to needing a charge but it might be too big/bulky for your host. It essentially is a fixed constant current source in a relatively small package and is available in 20mA, 25mA, and 30mA versions. The picture below shows one attached to one leg of a 5mm LED so you can get some sense of its size.



Otherwise you could use a smaller, much cheaper resistor. Assuming the LED is a 3V (not a 12V), with two batteries and driving the LED at 20mA the resistor value is 220 Ohms [R=(2x3.7-3.0)/0.020], 1/10th Watt or greater (or use 1/8th or greater and have some margin). With a fixed resistor, a fully charged battery at 4.2V creates ~25mA and at 3.2V it generates ~15mA. That's not super noticeable.
 
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RB astro

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Another beauty Billy.
+Rep from me buddy.

:yh:
 

badboybilly

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I posted this diagram of a host with two switches, one 'clicky' in the back that switches the batteries ON and OFF, and the other a momentary switch which connects the batteries to the Laser Diode Driver. It shows the wiring to the back of a switch that looks like yours. This might help you figure out how to use your switch. Are you using a momentary on yours? To get the LED to light up is not hard, I can walk you through it if you want to pursue it. Just send/post a picture of the back of your switch if it's different than what I posted.

I also recently came across this DynaOhm™ Variable Resistor that keeps the current level to the LED part of the switch constant even as the battery goes from fully charged to needing a charge but it might be too big/bulky for your host. It essentially is a fixed constant current source in a relatively small package and is available in 20mA, 25mA, and 30mA versions. The picture below shows one attached to one leg of a 5mm LED so you can get some sense of its size.



Otherwise you could use a smaller, much cheaper resistor. Assuming the LED is a 3V (not a 12V), with two batteries and driving the LED at 20mA the resistor value is 220 Ohms [R=(2x3.7-3.0)/0.020], 1/10th Watt or greater (or use 1/8th or greater and have some margin). With a fixed resistor, a fully charged battery at 4.2V creates ~25mA and at 3.2V it generates ~15mA. That's not super noticeable.

Bro the switch I used is very simple it has 4 outputs 2 for the led and 2 for the switch I tried many scenarios, like I said though in this particular situation I couldn't have the led work on the switch becouse I was just using it to complete the negative path for the laser, there's no wiring I cut off the 2 pins for the led and the 2 pins that were left were for the switch one was bent back to the case of the switch and the other to a brass washer to complete the battery negative,
In order to usu the led I would need to have wires going threw the host from positive and negative, as I said in the thread there was some moding to the switch and it just slides in and out, but works great.

Actually this switch in the pic isn't the exact one but very similar!
 

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Hibro

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Nice work billy. I love the host. +rep for your work
 

OVNI

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...I tried many scenarios, like I said though in this particular situation I couldn't have the led work on the switch becouse I was just using it to complete the negative path for the laser...
Sometimes switches just don't work. I ordered a bunch of 12mm LED switches like the one you pictured recently to use in some Eghemus hosts I have. About half weren't what was advertised or the LED just didn't work. These were all new switches. I noticed that almost all of the sellers (eBay) I ordered from had them dropped shipped from the same company. The quality control is pretty dismal. All of them tried to get me to keep it for a discount but I didn't need what I didn't order and said no and they're all refunding me anyway and not asking for them back.
 




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