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Sanwu Lasers - Offical thread

paul1598419

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The diode used to get 800 mW has such a large emitter that it produces a line instead of the dot that the single mode diode does. I have one putting out over 1 watt of power that I built and these highly divergent 638nm laser diodes are very inexpensive. They are likely using a long focal length single element or multi element lens to try to reduce the size of the line, which is why it is only 800 mW instead of a full watt. The single mode diode will give you a nice dot even with a short focal length aspheric lens.
 
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droidlaser

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Thank you paul1598419! That makes good sense and I knew it had to be something along those lines. I would want the 200mw in that case. The Guardians look like a very nice pocket carry unit.
 

paul1598419

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I think you will be happier with the single mode even though it is 4X less power. The 638nm diodes are much brighter than the older 660nm and 650nm red diodes. Good luck with your new laser.
 

droidlaser

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One other option on the Guardian I am a bit confused about is the "Smooth" versus "Stainless Smooth" Style option (both same price). Is one Aluminum and one Stainless - I thought they were all stainless steel except the Red Copper Guardian. :thanks: again paul1598419 for the help on the diode modes.
 

paul1598419

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Steel may feel good in the hand, but it stinks as a heat sink. It has a very low thermal capacity coefficient when compared to metals like copper or aluminum. Most heat sinks and hosts are made of aluminum because it is cheap, light and has a high capacity to move heat away from the laser diode and out to the air where it can be carried away. Copper is even better, but it is more expensive and softer.
 

Alaskan

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I wonder, since copper soaks up heat so well, and I've heard aluminum is good at transferring heat to the air, is the combination of a copper core and aluminum fins really better than just using copper alone? Or is it just a cost savings to use aluminum fins for both material and machinability?
 

RedCowboy

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Copper is a good heat mover but will tarnish when regularly handled.
 

paul1598419

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Thermal conductivity is the measure of a substance's ability to hold or move heat. Since copper has a higher thermal conductivity than aluminum it is better for moving heat into the air than aluminum. I've heard people say that copper cores surrounded by aluminum works best for moving heat into the air, but never give a reason for this. It is just wrong. Only the thermal conductivity is the measure of this ability.
 

Alaskan

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Some posts on this here: https://arstechnica.com/civis/viewtopic.php?t=811894&start=40

Seems aluminum is chosen more often due to its lower cost and ease of machining, & its higher durability in regard to softness and its superior resistance to oxidation causing copper to discolor so quickly, especially with handling. Of course, environment plays a factor, i.e. wet with salt air will degrade either quickly, unless the alum. is anodized.
 
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Podo

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You can now select "magnetic controls" for the striker saber laser!
Mag.png

Magnetic control rings(Optional)
The magnetic control rings allow user to adjust the power of the laser from 100mW to 5000mW(5W 445nm for example) by twisting the control rings along with the control to the operation mode.
 
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Pelagius

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Very cool!

You can now select "magnetic controls" for the striker saber laser!
View attachment 61348

Magnetic control rings(Optional)
The magnetic control rings allow user to adjust the power of the laser from 100mW to 5000mW(5W 445nm for example) by twisting the control rings along with the control to the operation mode.
 

Gazen

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Nice, but $50 is pretty pricey. Any updates on the rgb or lpm? :) Hopefully they'll be out by next Easter.
 

Accutronitis

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I wonder, since copper soaks up heat so well, and I've heard aluminum is good at transferring heat to the air, is the combination of a copper core and aluminum fins really better than just using copper alone? Or is it just a cost savings to use aluminum fins for both material and machinability?
Thats what intel does with their top of the line OEM CPU air coolers "combination of a copper core and aluminum fins" So there must be something to it I would think.

Here are some solid 99.9% copper cores straight out of two such OEM coolers...



The rest of one of those coolers is part of my "Hammer"...
 
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Cyparagon

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I wonder, since copper soaks up heat so well
Just some fun with numbers because I need to practice.

The specitic heat of Aluminium is 0.902 J/Cg (joules per degree C per gram)
The specific heat of copper is 0.385

However, since copper has a density of 8.96g/ml, and aluminium has a density of 2.7g/ml, holding the volumes equal (since this is often the limiting factor) instead of weight gives figures of 3.45 J/Cml for copper and 2.44 J/Cml for aluminium. It isn't a particularly large difference. Making your aluminium block slightly larger would hold the same amount of heat as the copper one would. Since Aluminium is way cheaper and easy to machine, it may be a better choice in some scenarios.
 




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