1W 520 in a 501B host W/ Pictures

hello friends.
I'd like to introduce you to the newest laser in my collection: The NDG7475 520nm diode in a 501B host.
I kept the build pretty simple but I feel like it is exactly what I wanted. Thank you to DTR and Blord for answering a few questions about the diode and host. :beer:

When I decided I wanted to build a laser with this diode I immediately started looking for a perfect host. I'm not the type to have large bulky hosts even with the trade off of long duty cycles so I started looking into the 501B blord was selling with its LARGE copper heat sink. PERFECT.
next I wanted high quality batteries to power this beast so I looked around and found Keeppower was selling a decent 18350. however I haven't used these before so I queried the forum about them and found them to be tested well with Panasonic cells.
Not pictured in this Building process is the module in the heat sink. I guess when I was putting it together I didn't pause to photo splicing the wires and heat shrinking the connections. something you have all seen.

One issue I thought I might have is soldering the contact blank to the heatsink. I knew it would take a lot of heat but I couldn't get the blank to stick. A tip Blord mentioned was to put an excess solder blob on the side of the blank and press it into the heat sink. I soldered two wires on and carefully bent them around the blank and they ensured a firm fit. A quick resistance test ensured that the ground was solid and there was very little resistance.

Ok now We're up and running

This laser is very powerful, typically we associate "good burners" with the 405s and the 445/450s but I tried to get a photo of the output at 4 feet against a black surface and it caused the surface to smoke rapidly. (I should have photographed it at 20feet for a better picture)

This diode, like the 9mm ,has a rectangular shape and a box underneath(G2 lens) and with a three element lens beam quality is improved but does have some dim wings.

Power readings
When I ordered the driver from DTR I requested the driver set light so i would have better chances of a nice healthy life. I measured a bit over 1W. Note: these batteries didn't start off fully charged. I measured voltage to be 3.9V each so its possible that when fully charged I could increase this output.

lets see some more beam shots!
1W 520 vs 2.7W 445

Conclusion.
I love this laser. Beam quality isn't excellent but its really not feasible for indoor use(i used goggles) and outside its not a big deal. After about 30-40seconds i can feel the head get warm but certainly not hot. One thing I did not do was heat sink the driver. If I have time I might do that at a later date. the batteries seem to be able to handle the power requirements i measured a current draw of 1.9A at the tail cap which is a little higher than my other lasers but after 30seconds they were reasonably cool. AWESOME LASER
hope you enjoyed
Comments suggestions always welcome
thanks
Jefferson




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I may have to bite the bullet and get one of these.

I would DEFINITELY heatsink the driver. At 2.4a or whatever it's set at, a heatsink would be ideal for such an expensive build.

Awesome job. Thanks for rubbing it in, I mean sharing

The driver is set somewhere around 2.3a, when I get back to my house I have some small copper tubing that can be thermal adhesived to the driver and still fit in the heat sink. I did the same with the 9mm 2.7W.

very cool.. how hot does that thing get really? like a 445 laser or more?

Nice laser! I would love to make one of those 1W 520nm but I cannot justify the cost. Having owned one now do you think it was worth the 700 price tag?

I've never seen a watt of green, bet you do need goggles indoors. Nice choice of hosts.

Great build. Nice touch with the green host. Glad it worked out as you wanted.:beer:

Tmack said:

I may have to bite the bullet and get one of these.

I would DEFINITELY heatsink the driver. At 2.4a or whatever it's set at, a heatsink would be ideal for such an expensive build.

Awesome job. Thanks for rubbing it in, I mean sharing

Click to expand...

Why "DEFINITELY"? In that host I would really not suggest trying to keep over 120 second duty cycles with this diode actually probably much lower with the heat these diodes create plus it is an extra step where a mistake could be make with this expensive module although unlikely to mess up heatsinking but I have seen people do it. In my opinion if it ain't broke don't fix it.

Nice work

The green host looks very nice ... :beer:

I would just make everything as strong and solid as possible. Even though it's not needed to function, wouldn't you want to take every precaution possible? Something as easy as heatsinking the driver does more good than it is trouble to do.

If it were MINE, I would DEFINITELY do it

$700 diode is expensive to a guy like me. And after I did everything I could to build it strong, I don't want to have to crack it open for a long time.

Sure I respect your opinion and like to sink the drivers myself but in this case where there is not any realized benefit unless he wants to run the diode longer than 120 seconds I would not suggest the extra steps.

Not sure what sinking would be a precaution against or how it make it more solid/strong? The built in thermal shutdown in the driver is the precaution. As far as solid/strong it keeps a constant current at all times so it should not have a problem with strong and operates within a temperature range that is fine for the driver. I have yet to see an X-drive just give out from running unsinked so I don't see a solid issue.

Sinking it an upgrade to add a feature that takes the runtime from 120 seconds to unlimited and hey if anything it could protect the diode if left on too long as it will let you know by shutting off which could save the diode from overheating.:beer:

LOL, $700 diode in a $8 host. I can respect needing your 520 fix, RIGHT NOW.
I just did the same thing for the new 405 I got, was going to get a fancy single 26650 host but got impatient and said screw it

Thanks everyone for their input.
This is a diode I have saved up a long time for and The price tag was very hefty but it is one of the most beautiful colors I have ever seen. Worth it? Yea. Personally I prefer the deep green of the 520 rather than the lime green of the 532. I took this build very seriously and did some research before just diving in. Though I was anxious to finish it I check my connections, rechecked my connections, verified my battery voltages, applied a coating of Arctic Silver between my module and heatsink. i went through the steps in my mind how I was going to proceed throughout the whole process. Another precaution I took was left the aluminum module housing on. In my opinion it aids in heat transfer to the copper heat sink itself. I trimmed the wires and had plenty of room between the blank contact and the back of the module.

Where I am right now I don't have access to thermal apoxy. When I get to my desk if its feasible I will try to heat sink the driver. I don't know about you guys but I RARELY ever exceed 25seconds run time.
Tonight I can do a quick test. Ill do a 40 sec. on then measure the temp of the heatsink of both the 520 and the 9mm 445 i have. Ideally we would do this with two identical builds but the 445 is built with a Mrcrouse V12 aluminum host.

I still have to say my favorite laser is the JDSU argon Cheech sold me. But this laser comes in a close second.
Indoors goggles i would really recommend. It's just so damn bright.

I have never heatsinked a driver

Lol, thought about it many times but I am always afraid I will short something. Leaving it hanging there doesn't pose a problem for any of my builds so I don't sweat it.

wannaburnstuff said:

I have never heatsinked a diode

Click to expand...

You mean driver? Some I have some I haven't.
I know I store all my lasers in a hard case with foam padding because knowing me I would drop this laser or it would fall out of my pocket. There's nothing more scary if you've ever had that happen.

Whoops, yeah driver is what I meant lol.

Good point about the driver being a fail safe. With a small host like this, I guess there is no need.
Maybe strong /solid were a bad choice of words. Consider my recommendation, thoroughly disproven and retracted.

Heatsinking them has worked well for me. So I'll continue to do mine, but I can see how it may be overkill.