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Great Find!

Joined
Apr 11, 2019
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58
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8
So I came across a "8 watt laser module", with a power supply, adapter and heat sync with fan, that was priced at only $76. Immediately I felt skeptical, since the cheapest I've been able to find a just raw 7 watt blue diode is around $80, and it was a Chinese seller. But since there were some positive reviews, I decided to take a risk and buy it. I assumed there was no way it was near 8 watts. I was partially mistaken.

I don't have a laser meter, but I estimate it's a least 4-5+ watts. This is because I put it up against laser pointers with a confirmed 5 watt output and did similar if not better for burning capabilities with similar focus settings. That said, the divergence is really bad. You can adjust the focus, but it spreads really fast. I think it may be the lens, cause even when I have it at the best focus for long range, I still see that the width of the beam near the lens is very small as if its focused.(Sorry my knowledge on lenses is a bit newbish)

I just wanted to share the link here cause regardless of the wattage rating being exaggerated, I still think this is a pretty awesome deal.

eBay link: https://www.ebay.ca/itm/PWM-Blue-Laser-Engraving-Module-Focusable-450nm-8W-High-Power-Etcher-Laser/264137784877?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m2749.l2649
 



RedCowboy

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Jul 10, 2015
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If it's a de-canned diode and it probably is then it won't last, if de-canned then it will be down to half output in a month of daily light to moderate use.
 
Joined
Apr 11, 2019
Messages
58
Points
8
If it's a de-canned diode and it probably is then it won't last, if de-canned then it will be down to half output in a month of daily light to moderate use.

Even so, laser pointers in this power range are usually $200-$500. $76 doesn't set you back very far. I think it's perfectly fine for a hobbyist looking to make something out of it. The fan cooling will extend it's life I'm sure, I had it on for 3-4 minutes straight and it was barely warm to touch.

Buying any laser is always a risk. There's always a chance a diode can burn out or wear out faster than expected, like a light bulb.
 

RedCowboy

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I would rather have a 5.5w 7A75 than a 6.5w 08 for a home CNC because the beam is tighter and rounder, also the 7A75 has a window can and will last 10 times as long as a de-canned 08, but when buying from China you get what you get, if you decide to upgrade later you can get a NDB7A75 from DTR HERE
 
Joined
Apr 11, 2019
Messages
58
Points
8
I would rather have a 5.5w 7A75 than a 6.5w 08 for a home CNC because the beam is tighter and rounder, also the 7A75 has a window can and will last 10 times as long as a de-canned 08, but when buying from China you get what you get, if you decide to upgrade later you can get a NDB7A75 from DTR HERE

I'm just using this to make a laser pistol for fun. Watt per dollar is all I'm after. :)
 

paul1598419

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Sep 20, 2013
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Your question about the lens does not apply here. The reason the divergence is so awful is because the emitter face of these higher power blue diodes is very large in comparison to the lower power multi-mode diodes below 3 watts. You will not find a 7 watt diode anywhere that doesn't look this way.
 
Joined
Apr 11, 2019
Messages
58
Points
8
Your question about the lens does not apply here. The reason the divergence is so awful is because the emitter face of these higher power blue diodes is very large in comparison to the lower power multi-mode diodes below 3 watts. You will not find a 7 watt diode anywhere that doesn't look this way.

I'm probably not in much of a place to debate here, but my other laser pointers are also high power blue diodes, same wavelength. I took the lens off of both my old 5 watt laser pointer and the new module. The raw diode flash light on the wall at the same distance, was actually smaller on the new one. Not sure if that says much or not. I also noticed that the lens looks almost like a ball lens on the new module.
 

paul1598419

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Sep 20, 2013
Messages
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You can get the divergence down to a degree using a longer FL lens and/or using a beam expander. This will give you less divergence at the expense of having a larger diameter beam leaving the aperture, and less power.
 




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